Commit Graph

16953 Commits

Author SHA1 Message Date
Gavin Shan
fda88cfda1 mm/debug_vm_pgtable: remove unused code
The variables used by old implementation isn't needed as we switched to
"struct pgtable_debug_args".  Lets remove them and related code in
debug_vm_pgtable().

Link: https://lkml.kernel.org/r/20210809092631.1888748-12-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:10 -07:00
Gavin Shan
2f87f8c39a mm/debug_vm_pgtable: use struct pgtable_debug_args in PGD and P4D modifying tests
This uses struct pgtable_debug_args in PGD/P4D modifying tests.  No
allocated huge page is used in these tests.  Besides, the unused variable
@saved_p4dp and @saved_pudp are dropped.

Link: https://lkml.kernel.org/r/20210809092631.1888748-11-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:10 -07:00
Gavin Shan
4cbde03bdb mm/debug_vm_pgtable: use struct pgtable_debug_args in PUD modifying tests
This uses struct pgtable_debug_args in PUD modifying tests.  The allocated
huge page is used when set_pud_at() is used.  The corresponding tests are
skipped if the huge page doesn't exist.  Besides, the following unused
variables in debug_vm_pgtable() are dropped: @prot, @paddr, @pud_aligned.

Link: https://lkml.kernel.org/r/20210809092631.1888748-10-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
c0fe07b0aa mm/debug_vm_pgtable: use struct pgtable_debug_args in PMD modifying tests
This uses struct pgtable_debug_args in PMD modifying tests.  The allocated
huge page is used when set_pmd_at() is used.  The corresponding tests are
skipped if the huge page doesn't exist.  Besides, the unused variable
@pmd_aligned in debug_vm_pgtable() is dropped.

Link: https://lkml.kernel.org/r/20210809092631.1888748-9-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
44966c4480 mm/debug_vm_pgtable: use struct pgtable_debug_args in PTE modifying tests
This uses struct pgtable_debug_args in PTE modifying tests.  The allocated
page is used as set_pte_at() is used there.  The tests are skipped if the
allocated page doesn't exist.  It's notable that args->ptep need to be
mapped before the tests.  The reason why we don't map args->ptep at the
beginning is PTE entry is only mapped and accessible in atomic context
when CONFIG_HIGHPTE is enabled.  So we avoid to do that so that atomic
context is only enabled if needed.

Besides, the unused variable @pte_aligned and @ptep in debug_vm_pgtable()
are dropped.

Link: https://lkml.kernel.org/r/20210809092631.1888748-8-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
4878a88882 mm/debug_vm_pgtable: use struct pgtable_debug_args in migration and thp tests
This uses struct pgtable_debug_args in the migration and thp test
functions.  It's notable that the pre-allocated page is used in
swap_migration_tests() as set_pte_at() is used there.

Link: https://lkml.kernel.org/r/20210809092631.1888748-7-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
5f447e8067 mm/debug_vm_pgtable: use struct pgtable_debug_args in soft_dirty and swap tests
This uses struct pgtable_debug_args in the soft_dirty and swap test
functions.

Link: https://lkml.kernel.org/r/20210809092631.1888748-6-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
8cb183f2f2 mm/debug_vm_pgtable: use struct pgtable_debug_args in protnone and devmap tests
This uses struct pgtable_debug_args in protnone and devmap test functions.
After that, the unused variable @protnone in debug_vm_pgtable() is
dropped.

Link: https://lkml.kernel.org/r/20210809092631.1888748-5-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
8983d231c7 mm/debug_vm_pgtable: use struct pgtable_debug_args in leaf and savewrite tests
This uses struct pgtable_debug_args in the leaf and savewrite test
functions.

Link: https://lkml.kernel.org/r/20210809092631.1888748-4-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
36b77d1e15 mm/debug_vm_pgtable: use struct pgtable_debug_args in basic tests
This uses struct pgtable_debug_args in the basic test functions.  The
unused variables @pgd_aligned and @p4d_aligned in debug_vm_pgtable() are
dropped.

Link: https://lkml.kernel.org/r/20210809092631.1888748-3-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
Gavin Shan
3c9b84f044 mm/debug_vm_pgtable: introduce struct pgtable_debug_args
Patch series "mm/debug_vm_pgtable: Enhancements", v6.

There are a couple of issues with current implementations and this series
tries to resolve the issues:

  (a) All needed information are scattered in variables, passed to various
      test functions. The code is organized in pretty much relaxed fashion.

  (b) The page isn't allocated from buddy during page table entry modifying
      tests. The page can be invalid, conflicting to the implementations
      of set_xxx_at() on ARM64. The target page is accessed so that the
      iCache can be flushed when execution permission is given on ARM64.
      Besides, the target page can be unmapped and accessing to it causes
      kernel crash.

"struct pgtable_debug_args" is introduced to address issue (a).  For issue
(b), the used page is allocated from buddy in page table entry modifying
tests.  The corresponding tets will be skipped if we fail to allocate the
(huge) page.  For other test cases, the original page around to kernel
symbol (@start_kernel) is still used.

The patches are organized as below.  PATCH[2-10] could be combined to one
patch, but it will make the review harder:

  PATCH[1] introduces "struct pgtable_debug_args" as place holder of all
           needed information. With it, the old and new implementation
           can coexist.
  PATCH[2-10] uses "struct pgtable_debug_args" in various test functions.
  PATCH[11] removes the unused code for old implementation.
  PATCH[12] fixes the issue of corrupted page flag for ARM64

This patch (of 6):

In debug_vm_pgtable(), there are many local variables introduced to track
the needed information and they are passed to the functions for various
test cases.  It'd better to introduce a struct as place holder for these
information.  With it, what the tests functions need is the struct.  In
this way, the code is simplified and easier to be maintained.

Besides, set_xxx_at() could access the data on the corresponding pages in
the page table modifying tests.  So the accessed pages in the tests should
have been allocated from buddy.  Otherwise, we're accessing pages that
aren't owned by us.  This causes issues like page flag corruption or
kernel crash on accessing unmapped page when CONFIG_DEBUG_PAGEALLOC is
enabled.

This introduces "struct pgtable_debug_args".  The struct is initialized
and destroyed, but the information in the struct isn't used yet.  It will
be used in subsequent patches.

Link: https://lkml.kernel.org/r/20210809092631.1888748-1-gshan@redhat.com
Link: https://lkml.kernel.org/r/20210809092631.1888748-2-gshan@redhat.com
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>	[powerpc 8xx]
Tested-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>	[s390]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03 09:58:09 -07:00
David Hildenbrand
6128b3af2a mm: ignore MAP_DENYWRITE in ksys_mmap_pgoff()
Let's also remove masking off MAP_DENYWRITE from ksys_mmap_pgoff():
the last in-tree occurrence of MAP_DENYWRITE is now in LEGACY_MAP_MASK,
which accepts the flag e.g., for MAP_SHARED_VALIDATE; however, the flag
is ignored throughout the kernel now.

Add a comment to LEGACY_MAP_MASK stating that MAP_DENYWRITE is ignored.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
2021-09-03 18:42:01 +02:00
David Hildenbrand
8d0920bde5 mm: remove VM_DENYWRITE
All in-tree users of MAP_DENYWRITE are gone. MAP_DENYWRITE cannot be
set from user space, so all users are gone; let's remove it.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
2021-09-03 18:42:01 +02:00
Linus Torvalds
612b23f277 memblock: robustness and debug improvements
* add check for memory add/cap ordering
 * add missing debug code to memblock_add_node()
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Merge tag 'memblock-v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock updates from Mike Rapoport:
 "Robustness and debug improvements:

   - add check for memory add/cap ordering

   - add missing debug code to memblock_add_node()"

* tag 'memblock-v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  memblock: Check memory add/cap ordering
  memblock: Add missing debug code to memblock_add_node()
2021-09-02 12:26:31 -07:00
Linus Torvalds
7661809d49 mm: don't allow oversized kvmalloc() calls
'kvmalloc()' is a convenience function for people who want to do a
kmalloc() but fall back on vmalloc() if there aren't enough physically
contiguous pages, or if the allocation is larger than what kmalloc()
supports.

However, let's make sure it doesn't get _too_ easy to do crazy things
with it.  In particular, don't allow big allocations that could be due
to integer overflow or underflow.  So make sure the allocation size fits
in an 'int', to protect against trivial integer conversion issues.

Acked-by: Willy Tarreau <w@1wt.eu>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-02 09:47:01 -07:00
Linus Torvalds
90c90cda05 New code for 5.15:
- Fix a potential log livelock on busy filesystems when there's so much
    work going on that we can't finish a quotaoff before filling up the log
    by removing the ability to disable quota accounting.
  - Introduce the ability to use per-CPU data structures in XFS so that
    we can do a better job of maintaining CPU locality for certain
    operations.
  - Defer inode inactivation work to per-CPU lists, which will help us
    batch that processing.  Deletions of large sparse files will *appear*
    to run faster, but all that means is that we've moved the work to the
    backend.
  - Drop the EXPERIMENTAL warnings from the y2038+ support and the inode
    btree counters, since it's been nearly a year and no complaints have
    come in.
  - Remove more of our bespoke kmem* variants in favor of using the
    standard Linux calls.
  - Prepare for the addition of log incompat features in upcoming cycles
    by actually adding code to support this.
  - Small cleanups of the xattr code in preparation for landing support
    for full logging of extended attribute updates in a future cycle.
  - Replace the various log shutdown state and flag code all over xfs
    with a single atomic bit flag.
  - Fix a serious log recovery bug where log item replay can be skipped
    based on the start lsn of a transaction even though the transaction
    commit lsn is the key data point for that by enforcing start lsns to
    appear in the log in the same order as commit lsns.
  - Enable pipelining in the code that pushes log items to disk.
  - Drop ->writepage.
  - Fix some bugs in GETFSMAP where the last fsmap record reported for a
    device could extend beyond the end of the device, and a separate bug
    where query keys for one device could be applied to another.
  - Don't let GETFSMAP query functions edit their input parameters.
  - Small cleanups to the scrub code's handling of perag structures.
  - Small cleanups to the incore inode tree walk code.
  - Constify btree function parameters that aren't changed, so that there
    will never again be confusion about range query functions changing
    their input parameters.
  - Standardize the format and names of tracepoint data attributes.
  - Clean up all the mount state and feature flags to use wrapped bitset
    functions instead of inconsistently open-coded flag checks.
  - Fix some confusion between xfs_buf hash table key variable vs. block
    number.
  - Fix a mis-interaction with iomap where we reported shared delalloc
    cow fork extents to iomap, which would cause the iomap unshare
    operation to return IO errors unnecessarily.
  - Fix DONTCACHE behavior.
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Merge tag 'xfs-5.15-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
 "There's a lot in this cycle.

  Starting with bug fixes: To avoid livelocks between the logging code
  and the quota code, we've disabled the ability of quotaoff to turn off
  quota accounting. (Admins can still disable quota enforcement, but
  truly turning off accounting requires a remount.) We've tried to do
  this in a careful enough way that there shouldn't be any user visible
  effects aside from quotaoff no longer randomly hanging the system.

  We've also fixed some bugs in runtime log behavior that could trip up
  log recovery if (otherwise unrelated) transactions manage to start and
  commit concurrently; some bugs in the GETFSMAP ioctl where we would
  incorrectly restrict the range of records output if the two xfs
  devices are of different sizes; a bug that resulted in fallocate
  funshare failing unnecessarily; and broken behavior in the xfs inode
  cache when DONTCACHE is in play.

  As for new features: we now batch inode inactivations in percpu
  background threads, which sharply decreases frontend thread wait time
  when performing file deletions and should improve overall directory
  tree deletion times. This eliminates both the problem where closing an
  unlinked file (especially on a frozen fs) can stall for a long time,
  and should also ease complaints about direct reclaim bogging down on
  unlinked file cleanup.

  Starting with this release, we've enabled pipelining of the XFS log.
  On workloads with high rates of metadata updates to different shards
  of the filesystem, multiple threads can be used to format committed
  log updates into log checkpoints.

  Lastly, with this release, two new features have graduated to
  supported status: inode btree counters (for faster mounts), and
  support for dates beyond Y2038. Expect these to be enabled by default
  in a future release of xfsprogs.

  Summary:

   - Fix a potential log livelock on busy filesystems when there's so
     much work going on that we can't finish a quotaoff before filling
     up the log by removing the ability to disable quota accounting.

   - Introduce the ability to use per-CPU data structures in XFS so that
     we can do a better job of maintaining CPU locality for certain
     operations.

   - Defer inode inactivation work to per-CPU lists, which will help us
     batch that processing. Deletions of large sparse files will
     *appear* to run faster, but all that means is that we've moved the
     work to the backend.

   - Drop the EXPERIMENTAL warnings from the y2038+ support and the
     inode btree counters, since it's been nearly a year and no
     complaints have come in.

   - Remove more of our bespoke kmem* variants in favor of using the
     standard Linux calls.

   - Prepare for the addition of log incompat features in upcoming
     cycles by actually adding code to support this.

   - Small cleanups of the xattr code in preparation for landing support
     for full logging of extended attribute updates in a future cycle.

   - Replace the various log shutdown state and flag code all over xfs
     with a single atomic bit flag.

   - Fix a serious log recovery bug where log item replay can be skipped
     based on the start lsn of a transaction even though the transaction
     commit lsn is the key data point for that by enforcing start lsns
     to appear in the log in the same order as commit lsns.

   - Enable pipelining in the code that pushes log items to disk.

   - Drop ->writepage.

   - Fix some bugs in GETFSMAP where the last fsmap record reported for
     a device could extend beyond the end of the device, and a separate
     bug where query keys for one device could be applied to another.

   - Don't let GETFSMAP query functions edit their input parameters.

   - Small cleanups to the scrub code's handling of perag structures.

   - Small cleanups to the incore inode tree walk code.

   - Constify btree function parameters that aren't changed, so that
     there will never again be confusion about range query functions
     changing their input parameters.

   - Standardize the format and names of tracepoint data attributes.

   - Clean up all the mount state and feature flags to use wrapped
     bitset functions instead of inconsistently open-coded flag checks.

   - Fix some confusion between xfs_buf hash table key variable vs.
     block number.

   - Fix a mis-interaction with iomap where we reported shared delalloc
     cow fork extents to iomap, which would cause the iomap unshare
     operation to return IO errors unnecessarily.

   - Fix DONTCACHE behavior"

* tag 'xfs-5.15-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (103 commits)
  xfs: fix I_DONTCACHE
  xfs: only set IOMAP_F_SHARED when providing a srcmap to a write
  xfs: fix perag structure refcounting error when scrub fails
  xfs: rename buffer cache index variable b_bn
  xfs: convert bp->b_bn references to xfs_buf_daddr()
  xfs: introduce xfs_buf_daddr()
  xfs: kill xfs_sb_version_has_v3inode()
  xfs: introduce xfs_sb_is_v5 helper
  xfs: remove unused xfs_sb_version_has wrappers
  xfs: convert xfs_sb_version_has checks to use mount features
  xfs: convert scrub to use mount-based feature checks
  xfs: open code sb verifier feature checks
  xfs: convert xfs_fs_geometry to use mount feature checks
  xfs: replace XFS_FORCED_SHUTDOWN with xfs_is_shutdown
  xfs: convert remaining mount flags to state flags
  xfs: convert mount flags to features
  xfs: consolidate mount option features in m_features
  xfs: replace xfs_sb_version checks with feature flag checks
  xfs: reflect sb features in xfs_mount
  xfs: rework attr2 feature and mount options
  ...
2021-09-02 08:26:03 -07:00
Linus Torvalds
57c78a234e arm64 updates for 5.15:
- Support for 32-bit tasks on asymmetric AArch32 systems (on top of the
   scheduler changes merged via the tip tree).
 
 - More entry.S clean-ups and conversion to C.
 
 - MTE updates: allow a preferred tag checking mode to be set per CPU
   (the overhead of synchronous mode is smaller for some CPUs than
   others); optimisations for kernel entry/exit path; optionally disable
   MTE on the kernel command line.
 
 - Kselftest improvements for SVE and signal handling, PtrAuth.
 
 - Fix unlikely race where a TLBI could use stale ASID on an ASID
   roll-over (found by inspection).
 
 - Miscellaneous fixes: disable trapping of PMSNEVFR_EL1 to higher
   exception levels; drop unnecessary sigdelsetmask() call in the
   signal32 handling; remove BUG_ON when failing to allocate SVE state
   (just signal the process); SYM_CODE annotations.
 
 - Other trivial clean-ups: use macros instead of magic numbers, remove
   redundant returns, typos.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - Support for 32-bit tasks on asymmetric AArch32 systems (on top of the
   scheduler changes merged via the tip tree).

 - More entry.S clean-ups and conversion to C.

 - MTE updates: allow a preferred tag checking mode to be set per CPU
   (the overhead of synchronous mode is smaller for some CPUs than
   others); optimisations for kernel entry/exit path; optionally disable
   MTE on the kernel command line.

 - Kselftest improvements for SVE and signal handling, PtrAuth.

 - Fix unlikely race where a TLBI could use stale ASID on an ASID
   roll-over (found by inspection).

 - Miscellaneous fixes: disable trapping of PMSNEVFR_EL1 to higher
   exception levels; drop unnecessary sigdelsetmask() call in the
   signal32 handling; remove BUG_ON when failing to allocate SVE state
   (just signal the process); SYM_CODE annotations.

 - Other trivial clean-ups: use macros instead of magic numbers, remove
   redundant returns, typos.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (56 commits)
  arm64: Do not trap PMSNEVFR_EL1
  arm64: mm: fix comment typo of pud_offset_phys()
  arm64: signal32: Drop pointless call to sigdelsetmask()
  arm64/sve: Better handle failure to allocate SVE register storage
  arm64: Document the requirement for SCR_EL3.HCE
  arm64: head: avoid over-mapping in map_memory
  arm64/sve: Add a comment documenting the binutils needed for SVE asm
  arm64/sve: Add some comments for sve_save/load_state()
  kselftest/arm64: signal: Add a TODO list for signal handling tests
  kselftest/arm64: signal: Add test case for SVE register state in signals
  kselftest/arm64: signal: Verify that signals can't change the SVE vector length
  kselftest/arm64: signal: Check SVE signal frame shows expected vector length
  kselftest/arm64: signal: Support signal frames with SVE register data
  kselftest/arm64: signal: Add SVE to the set of features we can check for
  arm64: replace in_irq() with in_hardirq()
  kselftest/arm64: pac: Fix skipping of tests on systems without PAC
  Documentation: arm64: describe asymmetric 32-bit support
  arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores
  arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0
  arm64: Advertise CPUs capable of running 32-bit applications in sysfs
  ...
2021-09-01 15:04:29 -07:00
Linus Torvalds
9e9fb7655e Core:
- Enable memcg accounting for various networking objects.
 
 BPF:
 
  - Introduce bpf timers.
 
  - Add perf link and opaque bpf_cookie which the program can read
    out again, to be used in libbpf-based USDT library.
 
  - Add bpf_task_pt_regs() helper to access user space pt_regs
    in kprobes, to help user space stack unwinding.
 
  - Add support for UNIX sockets for BPF sockmap.
 
  - Extend BPF iterator support for UNIX domain sockets.
 
  - Allow BPF TCP congestion control progs and bpf iterators to call
    bpf_setsockopt(), e.g. to switch to another congestion control
    algorithm.
 
 Protocols:
 
  - Support IOAM Pre-allocated Trace with IPv6.
 
  - Support Management Component Transport Protocol.
 
  - bridge: multicast: add vlan support.
 
  - netfilter: add hooks for the SRv6 lightweight tunnel driver.
 
  - tcp:
     - enable mid-stream window clamping (by user space or BPF)
     - allow data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD
     - more accurate DSACK processing for RACK-TLP
 
  - mptcp:
     - add full mesh path manager option
     - add partial support for MP_FAIL
     - improve use of backup subflows
     - optimize option processing
 
  - af_unix: add OOB notification support.
 
  - ipv6: add IFLA_INET6_RA_MTU to expose MTU value advertised by
          the router.
 
  - mac80211: Target Wake Time support in AP mode.
 
  - can: j1939: extend UAPI to notify about RX status.
 
 Driver APIs:
 
  - Add page frag support in page pool API.
 
  - Many improvements to the DSA (distributed switch) APIs.
 
  - ethtool: extend IRQ coalesce uAPI with timer reset modes.
 
  - devlink: control which auxiliary devices are created.
 
  - Support CAN PHYs via the generic PHY subsystem.
 
  - Proper cross-chip support for tag_8021q.
 
  - Allow TX forwarding for the software bridge data path to be
    offloaded to capable devices.
 
 Drivers:
 
  - veth: more flexible channels number configuration.
 
  - openvswitch: introduce per-cpu upcall dispatch.
 
  - Add internet mix (IMIX) mode to pktgen.
 
  - Transparently handle XDP operations in the bonding driver.
 
  - Add LiteETH network driver.
 
  - Renesas (ravb):
    - support Gigabit Ethernet IP
 
  - NXP Ethernet switch (sja1105)
    - fast aging support
    - support for "H" switch topologies
    - traffic termination for ports under VLAN-aware bridge
 
  - Intel 1G Ethernet
     - support getcrosststamp() with PCIe PTM (Precision Time
       Measurement) for better time sync
     - support Credit-Based Shaper (CBS) offload, enabling HW traffic
       prioritization and bandwidth reservation
 
  - Broadcom Ethernet (bnxt)
     - support pulse-per-second output
     - support larger Rx rings
 
  - Mellanox Ethernet (mlx5)
     - support ethtool RSS contexts and MQPRIO channel mode
     - support LAG offload with bridging
     - support devlink rate limit API
     - support packet sampling on tunnels
 
  - Huawei Ethernet (hns3):
     - basic devlink support
     - add extended IRQ coalescing support
     - report extended link state
 
  - Netronome Ethernet (nfp):
     - add conntrack offload support
 
  - Broadcom WiFi (brcmfmac):
     - add WPA3 Personal with FT to supported cipher suites
     - support 43752 SDIO device
 
  - Intel WiFi (iwlwifi):
     - support scanning hidden 6GHz networks
     - support for a new hardware family (Bz)
 
  - Xen pv driver:
     - harden netfront against malicious backends
 
  - Qualcomm mobile
     - ipa: refactor power management and enable automatic suspend
     - mhi: move MBIM to WWAN subsystem interfaces
 
 Refactor:
 
  - Ambient BPF run context and cgroup storage cleanup.
 
  - Compat rework for ndo_ioctl.
 
 Old code removal:
 
  - prism54 remove the obsoleted driver, deprecated by the p54 driver.
 
  - wan: remove sbni/granch driver.
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - Enable memcg accounting for various networking objects.

  BPF:

   - Introduce bpf timers.

   - Add perf link and opaque bpf_cookie which the program can read out
     again, to be used in libbpf-based USDT library.

   - Add bpf_task_pt_regs() helper to access user space pt_regs in
     kprobes, to help user space stack unwinding.

   - Add support for UNIX sockets for BPF sockmap.

   - Extend BPF iterator support for UNIX domain sockets.

   - Allow BPF TCP congestion control progs and bpf iterators to call
     bpf_setsockopt(), e.g. to switch to another congestion control
     algorithm.

  Protocols:

   - Support IOAM Pre-allocated Trace with IPv6.

   - Support Management Component Transport Protocol.

   - bridge: multicast: add vlan support.

   - netfilter: add hooks for the SRv6 lightweight tunnel driver.

   - tcp:
       - enable mid-stream window clamping (by user space or BPF)
       - allow data-less, empty-cookie SYN with TFO_SERVER_COOKIE_NOT_REQD
       - more accurate DSACK processing for RACK-TLP

   - mptcp:
       - add full mesh path manager option
       - add partial support for MP_FAIL
       - improve use of backup subflows
       - optimize option processing

   - af_unix: add OOB notification support.

   - ipv6: add IFLA_INET6_RA_MTU to expose MTU value advertised by the
     router.

   - mac80211: Target Wake Time support in AP mode.

   - can: j1939: extend UAPI to notify about RX status.

  Driver APIs:

   - Add page frag support in page pool API.

   - Many improvements to the DSA (distributed switch) APIs.

   - ethtool: extend IRQ coalesce uAPI with timer reset modes.

   - devlink: control which auxiliary devices are created.

   - Support CAN PHYs via the generic PHY subsystem.

   - Proper cross-chip support for tag_8021q.

   - Allow TX forwarding for the software bridge data path to be
     offloaded to capable devices.

  Drivers:

   - veth: more flexible channels number configuration.

   - openvswitch: introduce per-cpu upcall dispatch.

   - Add internet mix (IMIX) mode to pktgen.

   - Transparently handle XDP operations in the bonding driver.

   - Add LiteETH network driver.

   - Renesas (ravb):
       - support Gigabit Ethernet IP

   - NXP Ethernet switch (sja1105):
       - fast aging support
       - support for "H" switch topologies
       - traffic termination for ports under VLAN-aware bridge

   - Intel 1G Ethernet
       - support getcrosststamp() with PCIe PTM (Precision Time
         Measurement) for better time sync
       - support Credit-Based Shaper (CBS) offload, enabling HW traffic
         prioritization and bandwidth reservation

   - Broadcom Ethernet (bnxt)
       - support pulse-per-second output
       - support larger Rx rings

   - Mellanox Ethernet (mlx5)
       - support ethtool RSS contexts and MQPRIO channel mode
       - support LAG offload with bridging
       - support devlink rate limit API
       - support packet sampling on tunnels

   - Huawei Ethernet (hns3):
       - basic devlink support
       - add extended IRQ coalescing support
       - report extended link state

   - Netronome Ethernet (nfp):
       - add conntrack offload support

   - Broadcom WiFi (brcmfmac):
       - add WPA3 Personal with FT to supported cipher suites
       - support 43752 SDIO device

   - Intel WiFi (iwlwifi):
       - support scanning hidden 6GHz networks
       - support for a new hardware family (Bz)

   - Xen pv driver:
       - harden netfront against malicious backends

   - Qualcomm mobile
       - ipa: refactor power management and enable automatic suspend
       - mhi: move MBIM to WWAN subsystem interfaces

  Refactor:

   - Ambient BPF run context and cgroup storage cleanup.

   - Compat rework for ndo_ioctl.

  Old code removal:

   - prism54 remove the obsoleted driver, deprecated by the p54 driver.

   - wan: remove sbni/granch driver"

* tag 'net-next-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1715 commits)
  net: Add depends on OF_NET for LiteX's LiteETH
  ipv6: seg6: remove duplicated include
  net: hns3: remove unnecessary spaces
  net: hns3: add some required spaces
  net: hns3: clean up a type mismatch warning
  net: hns3: refine function hns3_set_default_feature()
  ipv6: remove duplicated 'net/lwtunnel.h' include
  net: w5100: check return value after calling platform_get_resource()
  net/mlxbf_gige: Make use of devm_platform_ioremap_resourcexxx()
  net: mdio: mscc-miim: Make use of the helper function devm_platform_ioremap_resource()
  net: mdio-ipq4019: Make use of devm_platform_ioremap_resource()
  fou: remove sparse errors
  ipv4: fix endianness issue in inet_rtm_getroute_build_skb()
  octeontx2-af: Set proper errorcode for IPv4 checksum errors
  octeontx2-af: Fix static code analyzer reported issues
  octeontx2-af: Fix mailbox errors in nix_rss_flowkey_cfg
  octeontx2-af: Fix loop in free and unmap counter
  af_unix: fix potential NULL deref in unix_dgram_connect()
  dpaa2-eth: Replace strlcpy with strscpy
  octeontx2-af: Use NDC TX for transmit packet data
  ...
2021-08-31 16:43:06 -07:00
Linus Torvalds
87045e6546 for-5.15-tag
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Merge tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "The highlights of this round are integrations with fs-verity and
  idmapped mounts, the rest is usual mix of minor improvements, speedups
  and cleanups.

  There are some patches outside of btrfs, namely updating some VFS
  interfaces, all straightforward and acked.

  Features:

   - fs-verity support, using standard ioctls, backward compatible with
     read-only limitation on inodes with previously enabled fs-verity

   - idmapped mount support

   - make mount with rescue=ibadroots more tolerant to partially damaged
     trees

   - allow raid0 on a single device and raid10 on two devices,
     degenerate cases but might be useful as an intermediate step during
     conversion to other profiles

   - zoned mode block group auto reclaim can be disabled via sysfs knob

  Performance improvements:

   - continue readahead of node siblings even if target node is in
     memory, could speed up full send (on sample test +11%)

   - batching of delayed items can speed up creating many files

   - fsync/tree-log speedups
       - avoid unnecessary work (gains +2% throughput, -2% run time on
         sample load)
       - reduced lock contention on renames (on dbench +4% throughput,
         up to -30% latency)

  Fixes:

   - various zoned mode fixes

   - preemptive flushing threshold tuning, avoid excessive work on
     almost full filesystems

  Core:

   - continued subpage support, preparation for implementing remaining
     features like compression and defragmentation; with some
     limitations, write is now enabled on 64K page systems with 4K
     sectors, still considered experimental
       - no readahead on compressed reads
       - inline extents disabled
       - disabled raid56 profile conversion and mount

   - improved flushing logic, fixing early ENOSPC on some workloads

   - inode flags have been internally split to read-only and read-write
     incompat bit parts, used by fs-verity

   - new tree items for fs-verity
       - descriptor item
       - Merkle tree item

   - inode operations extended to be namespace-aware

   - cleanups and refactoring

  Generic code changes:

   - fs: new export filemap_fdatawrite_wbc

   - fs: removed sync_inode

   - block: bio_trim argument type fixups

   - vfs: add namespace-aware lookup"

* tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
  btrfs: reset replace target device to allocation state on close
  btrfs: zoned: fix ordered extent boundary calculation
  btrfs: do not do preemptive flushing if the majority is global rsv
  btrfs: reduce the preemptive flushing threshold to 90%
  btrfs: tree-log: check btrfs_lookup_data_extent return value
  btrfs: avoid unnecessarily logging directories that had no changes
  btrfs: allow idmapped mount
  btrfs: handle ACLs on idmapped mounts
  btrfs: allow idmapped INO_LOOKUP_USER ioctl
  btrfs: allow idmapped SUBVOL_SETFLAGS ioctl
  btrfs: allow idmapped SET_RECEIVED_SUBVOL ioctls
  btrfs: relax restrictions for SNAP_DESTROY_V2 with subvolids
  btrfs: allow idmapped SNAP_DESTROY ioctls
  btrfs: allow idmapped SNAP_CREATE/SUBVOL_CREATE ioctls
  btrfs: check whether fsgid/fsuid are mapped during subvolume creation
  btrfs: allow idmapped permission inode op
  btrfs: allow idmapped setattr inode op
  btrfs: allow idmapped tmpfile inode op
  btrfs: allow idmapped symlink inode op
  btrfs: allow idmapped mkdir inode op
  ...
2021-08-31 09:41:22 -07:00
Catalin Marinas
65266a7c6a Merge remote-tracking branch 'tip/sched/arm64' into for-next/core
* tip/sched/arm64: (785 commits)
  Documentation: arm64: describe asymmetric 32-bit support
  arm64: Remove logic to kill 32-bit tasks on 64-bit-only cores
  arm64: Hook up cmdline parameter to allow mismatched 32-bit EL0
  arm64: Advertise CPUs capable of running 32-bit applications in sysfs
  arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system
  arm64: exec: Adjust affinity for compat tasks with mismatched 32-bit EL0
  arm64: Implement task_cpu_possible_mask()
  sched: Introduce dl_task_check_affinity() to check proposed affinity
  sched: Allow task CPU affinity to be restricted on asymmetric systems
  sched: Split the guts of sched_setaffinity() into a helper function
  sched: Introduce task_struct::user_cpus_ptr to track requested affinity
  sched: Reject CPU affinity changes based on task_cpu_possible_mask()
  cpuset: Cleanup cpuset_cpus_allowed_fallback() use in select_fallback_rq()
  cpuset: Honour task_cpu_possible_mask() in guarantee_online_cpus()
  cpuset: Don't use the cpu_possible_mask as a last resort for cgroup v1
  sched: Introduce task_cpu_possible_mask() to limit fallback rq selection
  sched: Cgroup SCHED_IDLE support
  sched/topology: Skip updating masks for non-online nodes
  Linux 5.14-rc6
  lib: use PFN_PHYS() in devmem_is_allowed()
  ...
2021-08-31 09:10:00 +01:00
Linus Torvalds
679369114e for-5.15/block-2021-08-30
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Merge tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "Nothing major in here - lots of good cleanups and tech debt handling,
  which is also evident in the diffstats. In particular:

   - Add disk sequence numbers (Matteo)

   - Discard merge fix (Ming)

   - Relax disk zoned reporting restrictions (Niklas)

   - Bio error handling zoned leak fix (Pavel)

   - Start of proper add_disk() error handling (Luis, Christoph)

   - blk crypto fix (Eric)

   - Non-standard GPT location support (Dmitry)

   - IO priority improvements and cleanups (Damien)o

   - blk-throtl improvements (Chunguang)

   - diskstats_show() stack reduction (Abd-Alrhman)

   - Loop scheduler selection (Bart)

   - Switch block layer to use kmap_local_page() (Christoph)

   - Remove obsolete disk_name helper (Christoph)

   - block_device refcounting improvements (Christoph)

   - Ensure gendisk always has a request queue reference (Christoph)

   - Misc fixes/cleanups (Shaokun, Oliver, Guoqing)"

* tag 'for-5.15/block-2021-08-30' of git://git.kernel.dk/linux-block: (129 commits)
  sg: pass the device name to blk_trace_setup
  block, bfq: cleanup the repeated declaration
  blk-crypto: fix check for too-large dun_bytes
  blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN
  blk-zoned: allow zone management send operations without CAP_SYS_ADMIN
  block: mark blkdev_fsync static
  block: refine the disk_live check in del_gendisk
  mmc: sdhci-tegra: Enable MMC_CAP2_ALT_GPT_TEGRA
  mmc: block: Support alternative_gpt_sector() operation
  partitions/efi: Support non-standard GPT location
  block: Add alternative_gpt_sector() operation
  bio: fix page leak bio_add_hw_page failure
  block: remove CONFIG_DEBUG_BLOCK_EXT_DEVT
  block: remove a pointless call to MINOR() in device_add_disk
  null_blk: add error handling support for add_disk()
  virtio_blk: add error handling support for add_disk()
  block: add error handling for device_add_disk / add_disk
  block: return errors from disk_alloc_events
  block: return errors from blk_integrity_add
  block: call blk_register_queue earlier in device_add_disk
  ...
2021-08-30 18:52:11 -07:00
Linus Torvalds
08403e2174 SMP core updates:
- Replace get/put_online_cpus() in various places. The final removal will
     happen shortly before v5.15-rc1 when the rest of the patches have been
     merged.
 
   - Add debug code to help the analysis of CPU hotplug failures
 
   - A set of kernel doc updates
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Merge tag 'smp-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull SMP core updates from Thomas Gleixner:

 - Replace get/put_online_cpus() in various places. The final removal
   will happen shortly before v5.15-rc1 when the rest of the patches
   have been merged.

 - Add debug code to help the analysis of CPU hotplug failures

 - A set of kernel doc updates

* tag 'smp-core-2021-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  mm: Replace deprecated CPU-hotplug functions.
  md/raid5: Replace deprecated CPU-hotplug functions.
  Documentation: Replace deprecated CPU-hotplug functions.
  smp: Fix all kernel-doc warnings
  cpu/hotplug: Add debug printks for hotplug callback failures
  cpu/hotplug: Use DEVICE_ATTR_*() macro
  cpu/hotplug: Eliminate all kernel-doc warnings
  cpu/hotplug: Fix kernel doc warnings for __cpuhp_setup_state_cpuslocked()
  cpu/hotplug: Fix comment typo
  smpboot: Replace deprecated CPU-hotplug functions.
2021-08-30 14:10:07 -07:00
Linus Torvalds
c7a5238ef6 s390 updates for 5.15 merge window
- Improve ftrace code patching so that stop_machine is not required anymore.
   This requires a small common code patch acked by Steven Rostedt:
   https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/
 
 - Enable KCSAN for s390. This comes with a small common code change to fix a
   compile warning. Acked by Marco Elver:
   https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com
 
 - Add KFENCE support for s390. This also comes with a minimal x86 patch from
   Marco Elver who said also this can be carried via the s390 tree:
   https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/
 
 - More changes to prepare the decompressor for relocation.
 
 - Enable DAT also for CPU restart path.
 
 - Final set of register asm removal patches; leaving only three locations where
   needed and sane.
 
 - Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO support to
   hwcaps flags.
 
 - Cleanup hwcaps implementation.
 
 - Add new instructions to in-kernel disassembler.
 
 - Various QDIO cleanups.
 
 - Add SCLP debug feature.
 
 - Various other cleanups and improvements all over the place.
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Merge tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Improve ftrace code patching so that stop_machine is not required
   anymore. This requires a small common code patch acked by Steven
   Rostedt:

     https://lore.kernel.org/linux-s390/20210730220741.4da6fdf6@oasis.local.home/

 - Enable KCSAN for s390. This comes with a small common code change to
   fix a compile warning. Acked by Marco Elver:

     https://lore.kernel.org/r/20210729142811.1309391-1-hca@linux.ibm.com

 - Add KFENCE support for s390. This also comes with a minimal x86 patch
   from Marco Elver who said also this can be carried via the s390 tree:

     https://lore.kernel.org/linux-s390/YQJdarx6XSUQ1tFZ@elver.google.com/

 - More changes to prepare the decompressor for relocation.

 - Enable DAT also for CPU restart path.

 - Final set of register asm removal patches; leaving only three
   locations where needed and sane.

 - Add NNPA, Vector-Packed-Decimal-Enhancement Facility 2, PCI MIO
   support to hwcaps flags.

 - Cleanup hwcaps implementation.

 - Add new instructions to in-kernel disassembler.

 - Various QDIO cleanups.

 - Add SCLP debug feature.

 - Various other cleanups and improvements all over the place.

* tag 's390-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (105 commits)
  s390: remove SCHED_CORE from defconfigs
  s390/smp: do not use nodat_stack for secondary CPU start
  s390/smp: enable DAT before CPU restart callback is called
  s390: update defconfigs
  s390/ap: fix state machine hang after failure to enable irq
  KVM: s390: generate kvm hypercall functions
  s390/sclp: add tracing of SCLP interactions
  s390/debug: add early tracing support
  s390/debug: fix debug area life cycle
  s390/debug: keep debug data on resize
  s390/diag: make restart_part2 a local label
  s390/mm,pageattr: fix walk_pte_level() early exit
  s390: fix typo in linker script
  s390: remove do_signal() prototype and do_notify_resume() function
  s390/crypto: fix all kernel-doc warnings in vfio_ap_ops.c
  s390/pci: improve DMA translation init and exit
  s390/pci: simplify CLP List PCI handling
  s390/pci: handle FH state mismatch only on disable
  s390/pci: fix misleading rc in clp_set_pci_fn()
  s390/boot: factor out offset_vmlinux_info() function
  ...
2021-08-30 13:07:15 -07:00
Linus Torvalds
6f01c935d9 File locking changes for v5.15.
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Merge tag 'locks-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull file locking updates from Jeff Layton:
 "This starts with a couple of fixes for potential deadlocks in the
  fowner/fasync handling.

  The next patch removes the old mandatory locking code from the kernel
  altogether.

  The last patch cleans up rw_verify_area a bit more after the mandatory
  locking removal"

* tag 'locks-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  fs: clean up after mandatory file locking support removal
  fs: remove mandatory file locking support
  fcntl: fix potential deadlock for &fasync_struct.fa_lock
  fcntl: fix potential deadlocks for &fown_struct.lock
2021-08-30 12:38:13 -07:00
Linus Torvalds
aa99f3c2b9 \n
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Merge tag 'hole_punch_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fs hole punching vs cache filling race fixes from Jan Kara:
 "Fix races leading to possible data corruption or stale data exposure
  in multiple filesystems when hole punching races with operations such
  as readahead.

  This is the series I was sending for the last merge window but with
  your objection fixed - now filemap_fault() has been modified to take
  invalidate_lock only when we need to create new page in the page cache
  and / or bring it uptodate"

* tag 'hole_punch_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  filesystems/locking: fix Malformed table warning
  cifs: Fix race between hole punch and page fault
  ceph: Fix race between hole punch and page fault
  fuse: Convert to using invalidate_lock
  f2fs: Convert to using invalidate_lock
  zonefs: Convert to using invalidate_lock
  xfs: Convert double locking of MMAPLOCK to use VFS helpers
  xfs: Convert to use invalidate_lock
  xfs: Refactor xfs_isilocked()
  ext2: Convert to using invalidate_lock
  ext4: Convert to use mapping->invalidate_lock
  mm: Add functions to lock invalidate_lock for two mappings
  mm: Protect operations adding pages to page cache with invalidate_lock
  documentation: Sync file_operations members with reality
  mm: Fix comments mentioning i_mutex
2021-08-30 10:24:50 -07:00
Sebastian Andrzej Siewior
7625eccd18 mm: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-21-bigeasy@linutronix.de
2021-08-28 01:46:17 +02:00
Christian König
880121be11 mm/vmscan: add sync_shrinkers function v3
While unplugging a device the TTM shrinker implementation
needs a barrier to make sure that all concurrent shrink
operations are done and no other CPU is referring to a
device specific pool any more.

Taking and releasing the shrinker semaphore on the write
side after unmapping and freeing all pages from the device
pool should make sure that no shrinker is running in
paralell.

This allows us to avoid the contented mutex in the TTM pool
implementation for every alloc/free operation.

v2: rework the commit message to make clear why we need this
v3: rename the function and add more doc as suggested by Daniel

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210820120528.81114-2-christian.koenig@amd.com
2021-08-27 09:55:15 +02:00
Jakub Kicinski
97c78d0af5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/wwan/mhi_wwan_mbim.c - drop the extra arg.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-26 17:57:57 -07:00
Miaohe Lin
946746d1ad mm/memory_hotplug: fix potential permanent lru cache disable
If offline_pages failed after lru_cache_disable(), it forgot to do
lru_cache_enable() in error path.  So we would have lru cache disabled
permanently in this case.

Link: https://lkml.kernel.org/r/20210821094246.10149-3-linmiaohe@huawei.com
Fixes: d479960e44 ("mm: disable LRU pagevec during the migration temporarily")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-25 12:25:12 -07:00
Josef Bacik
5a798493b8 fs: add a filemap_fdatawrite_wbc helper
Btrfs sometimes needs to flush dirty pages on a bunch of dirty inodes in
order to reclaim metadata reservations.  Unfortunately most helpers in
this area are too smart for us:

1) The normal filemap_fdata* helpers only take range and sync modes, and
   don't give any indication of how much was written, so we can only
   flush full inodes, which isn't what we want in most cases.
2) The normal writeback path requires us to have the s_umount sem held,
   but we can't unconditionally take it in this path because we could
   deadlock.
3) The normal writeback path also skips inodes with I_SYNC set if we
   write with WB_SYNC_NONE.  This isn't the behavior we want under heavy
   ENOSPC pressure, we want to actually make sure the pages are under
   writeback before returning, and if another thread is in the middle of
   writing the file we may return before they're under writeback and
   miss our ordered extents and not properly wait for completion.
4) sync_inode() uses the normal writeback path and has the same problem
   as #3.

What we really want is to call do_writepages() with our wbc.  This way
we can make sure that writeback is actually started on the pages, and we
can control how many pages are written as a whole as we write many
inodes using the same wbc.  Accomplish this with a new helper that does
just that so we can use it for our ENOSPC flushing infrastructure.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2021-08-23 13:19:07 +02:00
Jeff Layton
f7e33bdbd6 fs: remove mandatory file locking support
We added CONFIG_MANDATORY_FILE_LOCKING in 2015, and soon after turned it
off in Fedora and RHEL8. Several other distros have followed suit.

I've heard of one problem in all that time: Someone migrated from an
older distro that supported "-o mand" to one that didn't, and the host
had a fstab entry with "mand" in it which broke on reboot. They didn't
actually _use_ mandatory locking so they just removed the mount option
and moved on.

This patch rips out mandatory locking support wholesale from the kernel,
along with the Kconfig option and the Documentation file. It also
changes the mount code to ignore the "mand" mount option instead of
erroring out, and to throw a big, ugly warning.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
2021-08-23 06:15:36 -04:00
Mike Kravetz
c7b1850dfb hugetlb: don't pass page cache pages to restore_reserve_on_error
syzbot hit kernel BUG at fs/hugetlbfs/inode.c:532 as described in [1].
This BUG triggers if the HPageRestoreReserve flag is set on a page in
the page cache.  It should never be set, as the routine
huge_add_to_page_cache explicitly clears the flag after adding a page to
the cache.

The only code other than huge page allocation which sets the flag is
restore_reserve_on_error.  It will potentially set the flag in rare out
of memory conditions.  syzbot was injecting errors to cause memory
allocation errors which exercised this specific path.

The code in restore_reserve_on_error is doing the right thing.  However,
there are instances where pages in the page cache were being passed to
restore_reserve_on_error.  This is incorrect, as once a page goes into
the cache reservation information will not be modified for the page
until it is removed from the cache.  Error paths do not remove pages
from the cache, so even in the case of error, the page will remain in
the cache and no reservation adjustment is needed.

Modify routines that potentially call restore_reserve_on_error with a
page cache page to no longer do so.

Note on fixes tag: Prior to commit 846be08578 ("mm/hugetlb: expand
restore_reserve_on_error functionality") the routine would not process
page cache pages because the HPageRestoreReserve flag is not set on such
pages.  Therefore, this issue could not be trigggered.  The code added
by commit 846be08578 ("mm/hugetlb: expand restore_reserve_on_error
functionality") is needed and correct.  It exposed incorrect calls to
restore_reserve_on_error which is the root cause addressed by this
commit.

[1] https://lore.kernel.org/linux-mm/00000000000050776d05c9b7c7f0@google.com/

Link: https://lkml.kernel.org/r/20210818213304.37038-1-mike.kravetz@oracle.com
Fixes: 846be08578 ("mm/hugetlb: expand restore_reserve_on_error functionality")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: <syzbot+67654e51e54455f1c585@syzkaller.appspotmail.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-20 11:31:42 -07:00
Johannes Weiner
57f29762cd mm: vmscan: fix missing psi annotation for node_reclaim()
In a debugging session the other day, Rik noticed that node_reclaim()
was missing memstall annotations.  This means we'll miss pressure and
lost productivity resulting from reclaim on an overloaded local NUMA
node when vm.zone_reclaim_mode is enabled.

There haven't been any reports, but that's likely because
vm.zone_reclaim_mode hasn't been a commonly used feature recently, and
the intersection between such setups and psi users is probably nil.

But secondary memory such as CXL-connected DIMMS, persistent memory etc,
and the page demotion patches that handle them
(https://lore.kernel.org/lkml/20210401183216.443C4443@viggo.jf.intel.com/)
could soon make this a more common codepath again.

Link: https://lkml.kernel.org/r/20210818152457.35846-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-20 11:31:42 -07:00
Naoya Horiguchi
fcc00621d8 mm/hwpoison: retry with shake_page() for unhandlable pages
HWPoisonHandlable() sometimes returns false for typical user pages due
to races with average memory events like transfers over LRU lists.  This
causes failures in hwpoison handling.

There's retry code for such a case but does not work because the retry
loop reaches the retry limit too quickly before the page settles down to
handlable state.  Let get_any_page() call shake_page() to fix it.

[naoya.horiguchi@nec.com: get_any_page(): return -EIO when retry limit reached]
  Link: https://lkml.kernel.org/r/20210819001958.2365157-1-naoya.horiguchi@linux.dev

Link: https://lkml.kernel.org/r/20210817053703.2267588-1-naoya.horiguchi@linux.dev
Fixes: 25182f05ff ("mm,hwpoison: fix race with hugetlb page allocation")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>		[5.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-20 11:31:42 -07:00
Johannes Weiner
f56ce412a5 mm: memcontrol: fix occasional OOMs due to proportional memory.low reclaim
We've noticed occasional OOM killing when memory.low settings are in
effect for cgroups.  This is unexpected and undesirable as memory.low is
supposed to express non-OOMing memory priorities between cgroups.

The reason for this is proportional memory.low reclaim.  When cgroups
are below their memory.low threshold, reclaim passes them over in the
first round, and then retries if it couldn't find pages anywhere else.
But when cgroups are slightly above their memory.low setting, page scan
force is scaled down and diminished in proportion to the overage, to the
point where it can cause reclaim to fail as well - only in that case we
currently don't retry, and instead trigger OOM.

To fix this, hook proportional reclaim into the same retry logic we have
in place for when cgroups are skipped entirely.  This way if reclaim
fails and some cgroups were scanned with diminished pressure, we'll try
another full-force cycle before giving up and OOMing.

[akpm@linux-foundation.org: coding-style fixes]

Link: https://lkml.kernel.org/r/20210817180506.220056-1-hannes@cmpxchg.org
Fixes: 9783aa9917 ("mm, memcg: proportional memory.{low,min} reclaim")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Leon Yang <lnyng@fb.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>		[5.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-20 11:31:42 -07:00
Doug Berger
47aef6010b mm/page_alloc: don't corrupt pcppage_migratetype
When placing pages on a pcp list, migratetype values over
MIGRATE_PCPTYPES get added to the MIGRATE_MOVABLE pcp list.

However, the actual migratetype is preserved in the page and should
not be changed to MIGRATE_MOVABLE or the page may end up on the wrong
free_list.

The impact is that HIGHATOMIC or CMA pages getting bulk freed from the
PCP lists could potentially end up on the wrong buddy list.  There are
various consequences but minimally NR_FREE_CMA_PAGES accounting could
get screwed up.

[mgorman@techsingularity.net: changelog update]

Link: https://lkml.kernel.org/r/20210811182917.2607994-1-opendmb@gmail.com
Fixes: df1acc8569 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-20 11:31:42 -07:00
Yang Shi
c04b3d0690 Revert "mm: swap: check if swap backing device is congested or not"
Due to the change about how block layer detects congestion the
justification of commit 8fd2e0b505 ("mm: swap: check if swap backing
device is congested or not") doesn't stand anymore, so the commit could
be just reverted in order to solve the race reported by commit
2efa33fc7f ("mm/shmem: fix shmem_swapin() race with swapoff").  The
fix was reverted by the previous patch.

Link: https://lkml.kernel.org/r/20210810202936.2672-3-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-20 11:31:42 -07:00
Yang Shi
b1e1ef3454 Revert "mm/shmem: fix shmem_swapin() race with swapoff"
Due to the change about how block layer detects congestion the
justification of commit 8fd2e0b505 ("mm: swap: check if swap backing
device is congested or not") doesn't stand anymore, so the commit could
be just reverted in order to solve the race reported by commit
2efa33fc7f ("mm/shmem: fix shmem_swapin() race with swapoff"), so the
fix commit could be just reverted as well.

And that fix is also kind of buggy as discussed by [1] and [2].

[1] https://lore.kernel.org/linux-mm/24187e5e-069-9f3f-cefe-39ac70783753@google.com/
[2] https://lore.kernel.org/linux-mm/e82380b9-3ad4-4a52-be50-6d45c7f2b5da@google.com/

Link: https://lkml.kernel.org/r/20210810202936.2672-2-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-20 11:31:41 -07:00
Arnd Bergmann
2423de2e6f ARM: 9115/1: mm/maccess: fix unaligned copy_{from,to}_kernel_nofault
On machines such as ARMv5 that trap unaligned accesses, these
two functions can be slow when each access needs to be emulated,
or they might not work at all.

Change them so that each loop is only used when both the src
and dst pointers are naturally aligned.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20 11:39:25 +01:00
Jakub Kicinski
f444fea789 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/ptp/Kconfig:
  55c8fca1da ("ptp_pch: Restore dependency on PCI")
  e5f3155267 ("ethernet: fix PTP_1588_CLOCK dependencies")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-19 18:09:18 -07:00
Alexey Dobriyan
c0891ac15f isystem: ship and use stdarg.h
Ship minimal stdarg.h (1 type, 4 macros) as <linux/stdarg.h>.
stdarg.h is the only userspace header commonly used in the kernel.

GPL 2 version of <stdarg.h> can be extracted from
http://archive.debian.org/debian/pool/main/g/gcc-4.2/gcc-4.2_4.2.4.orig.tar.gz

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-08-19 09:02:55 +09:00
Wei Wang
4b1327be9f net-memcg: pass in gfp_t mask to mem_cgroup_charge_skmem()
Add gfp_t mask as an input parameter to mem_cgroup_charge_skmem(),
to give more control to the networking stack and enable it to change
memcg charging behavior. In the future, the networking stack may decide
to avoid oom-kills when fallbacks are more appropriate.

One behavior change in mem_cgroup_charge_skmem() by this patch is to
avoid force charging by default and let the caller decide when and if
force charging is needed through the presence or absence of
__GFP_NOFAIL.

Signed-off-by: Wei Wang <weiwan@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-18 11:39:44 +01:00
Waiman Long
7fa0dacbaf mm/memcg: fix incorrect flushing of lruvec data in obj_stock
When mod_objcg_state() is called with a pgdat that is different from
that in the obj_stock, the old lruvec data cached in obj_stock are
flushed out.  Unfortunately, they were flushed to the new pgdat and so
the data go to the wrong node.  This will screw up the slab data
reported in /sys/devices/system/node/node*/meminfo.

Fix that by flushing the data to the cached pgdat instead.

Link: https://lkml.kernel.org/r/20210802143834.30578-1-longman@redhat.com
Fixes: 68ac5b3c8d ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-13 14:09:32 -10:00
David Hildenbrand
eb2faa513c mm/madvise: report SIGBUS as -EFAULT for MADV_POPULATE_(READ|WRITE)
Doing some extended tests and polishing the man page update for
MADV_POPULATE_(READ|WRITE), I realized that we end up converting also
SIGBUS (via -EFAULT) to -EINVAL, making it look like yet another
madvise() user error.

We want to report only problematic mappings and permission problems that
the user could have know as -EINVAL.

Let's not convert -EFAULT arising due to SIGBUS (or SIGSEGV) to -EINVAL,
but instead indicate -EFAULT to user space.  While we could also convert
it to -ENOMEM, using -EFAULT looks more helpful when user space might
want to troubleshoot what's going wrong: MADV_POPULATE_(READ|WRITE) is
not part of an final Linux release and we can still adjust the behavior.

Link: https://lkml.kernel.org/r/20210726154932.102880-1-david@redhat.com
Fixes: 4ca9b3859d ("mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables")
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-13 14:09:31 -10:00
Vlastimil Babka
a7f1d48585 mm: slub: fix slub_debug disabling for list of slabs
Vijayanand Jitta reports:

  Consider the scenario where CONFIG_SLUB_DEBUG_ON is set and we would
  want to disable slub_debug for few slabs. Using boot parameter with
  slub_debug=-,slab_name syntax doesn't work as expected i.e; only
  disabling debugging for the specified list of slabs. Instead it
  disables debugging for all slabs, which is wrong.

This patch fixes it by delaying the moment when the global slub_debug
flags variable is updated.  In case a "slub_debug=-,slab_name" has been
passed, the global flags remain as initialized (depending on
CONFIG_SLUB_DEBUG_ON enabled or disabled) and are not simply reset to 0.

Link: https://lkml.kernel.org/r/8a3d992a-473a-467b-28a0-4ad2ff60ab82@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Vijayanand Jitta <vjitta@codeaurora.org>
Reviewed-by: Vijayanand Jitta <vjitta@codeaurora.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-13 14:09:31 -10:00
Shakeel Butt
1ed7ce574c slub: fix kmalloc_pagealloc_invalid_free unit test
The unit test kmalloc_pagealloc_invalid_free makes sure that for the
higher order slub allocation which goes to page allocator, the free is
called with the correct address i.e.  the virtual address of the head
page.

Commit f227f0faf6 ("slub: fix unreclaimable slab stat for bulk free")
unified the free code paths for page allocator based slub allocations
but instead of using the address passed by the caller, it extracted the
address from the page.  Thus making the unit test
kmalloc_pagealloc_invalid_free moot.  So, fix this by using the address
passed by the caller.

Should we fix this? I think yes because dev expect kasan to catch these
type of programming bugs.

Link: https://lkml.kernel.org/r/20210802180819.1110165-1-shakeelb@google.com
Fixes: f227f0faf6 ("slub: fix unreclaimable slab stat for bulk free")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-13 14:09:31 -10:00
Kuan-Ying Lee
340caf178d kasan, slub: reset tag when printing address
The address still includes the tags when it is printed.  With hardware
tag-based kasan enabled, we will get a false positive KASAN issue when
we access metadata.

Reset the tag before we access the metadata.

Link: https://lkml.kernel.org/r/20210804090957.12393-3-Kuan-Ying.Lee@mediatek.com
Fixes: aa1ef4d7b3 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-13 14:09:31 -10:00
Kuan-Ying Lee
6c7a00b843 kasan, kmemleak: reset tags when scanning block
Patch series "kasan, slub: reset tag when printing address", v3.

With hardware tag-based kasan enabled, we reset the tag when we access
metadata to avoid from false alarm.

This patch (of 2):

Kmemleak needs to scan kernel memory to check memory leak.  With hardware
tag-based kasan enabled, when it scans on the invalid slab and
dereference, the issue will occur as below.

Hardware tag-based KASAN doesn't use compiler instrumentation, we can not
use kasan_disable_current() to ignore tag check.

Based on the below report, there are 11 0xf7 granules, which amounts to
176 bytes, and the object is allocated from the kmalloc-256 cache.  So
when kmemleak accesses the last 256-176 bytes, it causes faults, as those
are marked with KASAN_KMALLOC_REDZONE == KASAN_TAG_INVALID == 0xfe.

Thus, we reset tags before accessing metadata to avoid from false positives.

  BUG: KASAN: out-of-bounds in scan_block+0x58/0x170
  Read at addr f7ff0000c0074eb0 by task kmemleak/138
  Pointer tag: [f7], memory tag: [fe]

  CPU: 7 PID: 138 Comm: kmemleak Not tainted 5.14.0-rc2-00001-g8cae8cd89f05-dirty #134
  Hardware name: linux,dummy-virt (DT)
  Call trace:
   dump_backtrace+0x0/0x1b0
   show_stack+0x1c/0x30
   dump_stack_lvl+0x68/0x84
   print_address_description+0x7c/0x2b4
   kasan_report+0x138/0x38c
   __do_kernel_fault+0x190/0x1c4
   do_tag_check_fault+0x78/0x90
   do_mem_abort+0x44/0xb4
   el1_abort+0x40/0x60
   el1h_64_sync_handler+0xb4/0xd0
   el1h_64_sync+0x78/0x7c
   scan_block+0x58/0x170
   scan_gray_list+0xdc/0x1a0
   kmemleak_scan+0x2ac/0x560
   kmemleak_scan_thread+0xb0/0xe0
   kthread+0x154/0x160
   ret_from_fork+0x10/0x18

  Allocated by task 0:
   kasan_save_stack+0x2c/0x60
   __kasan_kmalloc+0xec/0x104
   __kmalloc+0x224/0x3c4
   __register_sysctl_paths+0x200/0x290
   register_sysctl_table+0x2c/0x40
   sysctl_init+0x20/0x34
   proc_sys_init+0x3c/0x48
   proc_root_init+0x80/0x9c
   start_kernel+0x648/0x6a4
   __primary_switched+0xc0/0xc8

  Freed by task 0:
   kasan_save_stack+0x2c/0x60
   kasan_set_track+0x2c/0x40
   kasan_set_free_info+0x44/0x54
   ____kasan_slab_free.constprop.0+0x150/0x1b0
   __kasan_slab_free+0x14/0x20
   slab_free_freelist_hook+0xa4/0x1fc
   kfree+0x1e8/0x30c
   put_fs_context+0x124/0x220
   vfs_kern_mount.part.0+0x60/0xd4
   kern_mount+0x24/0x4c
   bdev_cache_init+0x70/0x9c
   vfs_caches_init+0xdc/0xf4
   start_kernel+0x638/0x6a4
   __primary_switched+0xc0/0xc8

  The buggy address belongs to the object at ffff0000c0074e00
   which belongs to the cache kmalloc-256 of size 256
  The buggy address is located 176 bytes inside of
   256-byte region [ffff0000c0074e00, ffff0000c0074f00)
  The buggy address belongs to the page:
  page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x100074
  head:(____ptrval____) order:2 compound_mapcount:0 compound_pincount:0
  flags: 0xbfffc0000010200(slab|head|node=0|zone=2|lastcpupid=0xffff|kasantag=0x0)
  raw: 0bfffc0000010200 0000000000000000 dead000000000122 f5ff0000c0002300
  raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff0000c0074c00: f0 f0 f0 f0 f0 f0 f0 f0 f0 fe fe fe fe fe fe fe
   ffff0000c0074d00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
  >ffff0000c0074e00: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 fe fe fe fe fe
                                                      ^
   ffff0000c0074f00: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
   ffff0000c0075000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ==================================================================
  Disabling lock debugging due to kernel taint
  kmemleak: 181 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

Link: https://lkml.kernel.org/r/20210804090957.12393-1-Kuan-Ying.Lee@mediatek.com
Link: https://lkml.kernel.org/r/20210804090957.12393-2-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-08-13 14:09:31 -10:00
Geert Uytterhoeven
e888fa7bb8 memblock: Check memory add/cap ordering
For memblock_cap_memory_range() to work properly, it should be called
after memory is detected and added to memblock with memblock_add() or
memblock_add_node().  If memblock_cap_memory_range() would be called
before memory is registered, we may silently corrupt memory later
because the crash kernel will see all memory as available.

Print a warning and bail out if ordering is not satisfied.

Suggested-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/aabc5bad008d49f07d542815c6c8d28ec90bb09e.1628672091.git.geert+renesas@glider.be
2021-08-11 14:50:50 +03:00
Geert Uytterhoeven
00974b9a83 memblock: Add missing debug code to memblock_add_node()
All other memblock APIs built on top of memblock_add_range() contain
debug code to print their parameters.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/c45e5218b6fcf0e3aeb63d9a9d9792addae0bb7a.1628672041.git.geert+renesas@glider.be
2021-08-11 14:50:42 +03:00
Dave Chinner
de2860f463 mm: Add kvrealloc()
During log recovery of an XFS filesystem with 64kB directory
buffers, rebuilding a buffer split across two log records results
in a memory allocation warning from krealloc like this:

xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff)
XFS (dm-0): Unmounting Filesystem
XFS (dm-0): Mounting V5 Filesystem
XFS (dm-0): Starting recovery (logdev: internal)
------------[ cut here ]------------
WARNING: CPU: 5 PID: 3435170 at mm/page_alloc.c:3539 get_page_from_freelist+0xdee/0xe40
.....
RIP: 0010:get_page_from_freelist+0xdee/0xe40
Call Trace:
 ? complete+0x3f/0x50
 __alloc_pages+0x16f/0x300
 alloc_pages+0x87/0x110
 kmalloc_order+0x2c/0x90
 kmalloc_order_trace+0x1d/0x90
 __kmalloc_track_caller+0x215/0x270
 ? xlog_recover_add_to_cont_trans+0x63/0x1f0
 krealloc+0x54/0xb0
 xlog_recover_add_to_cont_trans+0x63/0x1f0
 xlog_recovery_process_trans+0xc1/0xd0
 xlog_recover_process_ophdr+0x86/0x130
 xlog_recover_process_data+0x9f/0x160
 xlog_recover_process+0xa2/0x120
 xlog_do_recovery_pass+0x40b/0x7d0
 ? __irq_work_queue_local+0x4f/0x60
 ? irq_work_queue+0x3a/0x50
 xlog_do_log_recovery+0x70/0x150
 xlog_do_recover+0x38/0x1d0
 xlog_recover+0xd8/0x170
 xfs_log_mount+0x181/0x300
 xfs_mountfs+0x4a1/0x9b0
 xfs_fs_fill_super+0x3c0/0x7b0
 get_tree_bdev+0x171/0x270
 ? suffix_kstrtoint.constprop.0+0xf0/0xf0
 xfs_fs_get_tree+0x15/0x20
 vfs_get_tree+0x24/0xc0
 path_mount+0x2f5/0xaf0
 __x64_sys_mount+0x108/0x140
 do_syscall_64+0x3a/0x70
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Essentially, we are taking a multi-order allocation from kmem_alloc()
(which has an open coded no fail, no warn loop) and then
reallocating it out to 64kB using krealloc(__GFP_NOFAIL) and that is
then triggering the above warning.

This is a regression caused by converting this code from an open
coded no fail/no warn reallocation loop to using __GFP_NOFAIL.

What we actually need here is kvrealloc(), so that if contiguous
page allocation fails we fall back to vmalloc() and we don't
get nasty warnings happening in XFS.

Fixes: 771915c4f6 ("xfs: remove kmem_realloc()")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2021-08-09 15:57:43 -07:00
Christoph Hellwig
5ed964f8e5 mm: hide laptop_mode_wb_timer entirely behind the BDI API
Don't leak the detaіls of the timer into the block layer, instead
initialize the timer in bdi_alloc and delete it in bdi_unregister.
Note that this means the timer is initialized (but not armed) for
non-block queues as well now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210809141744.1203023-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-09 11:52:28 -06:00
Mark Rutland
7672150301 arm64: kasan: mte: remove redundant mte_report_once logic
We have special logic to suppress MTE tag check fault reporting, based
on a global `mte_report_once` and `reported` variables. These can be
used to suppress calling kasan_report() when taking a tag check fault,
but do not prevent taking the fault in the first place, nor does they
affect the way we disable tag checks upon taking a fault.

The core KASAN code already defaults to reporting a single fault, and
has a `multi_shot` control to permit reporting multiple faults. The only
place we transiently alter `mte_report_once` is in lib/test_kasan.c,
where we also the `multi_shot` state as the same time. Thus
`mte_report_once` and `reported` are redundant, and can be removed.

When a tag check fault is taken, tag checking will be disabled by
`do_tag_recovery` and must be explicitly re-enabled if desired. The test
code does this by calling kasan_enable_tagging_sync().

This patch removes the redundant mte_report_once() logic and associated
variables.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20210714143843.56537-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 18:15:28 +01:00
Mark Rutland
8286824789 arm64: kasan: mte: use a constant kernel GCR_EL1 value
When KASAN_HW_TAGS is selected, KASAN is enabled at boot time, and the
hardware supports MTE, we'll initialize `kernel_gcr_excl` with a value
dependent on KASAN_TAG_MAX. While the resulting value is a constant
which depends on KASAN_TAG_MAX, we have to perform some runtime work to
generate the value, and have to read the value from memory during the
exception entry path. It would be better if we could generate this as a
constant at compile-time, and use it as such directly.

Early in boot within __cpu_setup(), we initialize GCR_EL1 to a safe
value, and later override this with the value required by KASAN. If
CONFIG_KASAN_HW_TAGS is not selected, or if KASAN is disabeld at boot
time, the kernel will not use IRG instructions, and so the initial value
of GCR_EL1 is does not matter to the kernel. Thus, we can instead have
__cpu_setup() initialize GCR_EL1 to a value consistent with
KASAN_TAG_MAX, and avoid the need to re-initialize it during hotplug and
resume form suspend.

This patch makes arem64 use a compile-time constant KERNEL_GCR_EL1
value, which is compatible with KASAN_HW_TAGS when this is selected.
This removes the need to re-initialize GCR_EL1 dynamically, and acts as
an optimization to the entry assembly, which no longer needs to load
this value from memory. The redundant initialization hooks are removed.

In order to do this, KASAN_TAG_MAX needs to be visible outside of the
core KASAN code. To do this, I've moved the KASAN_TAG_* values into
<linux/kasan-tags.h>.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20210714143843.56537-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02 18:14:21 +01:00
Jakub Kicinski
d2e11fd2b7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicting commits, all resolutions pretty trivial:

drivers/bus/mhi/pci_generic.c
  5c2c853159 ("bus: mhi: pci-generic: configurable network interface MRU")
  56f6f4c4eb ("bus: mhi: pci_generic: Apply no-op for wake using sideband wake boolean")

drivers/nfc/s3fwrn5/firmware.c
  a0302ff590 ("nfc: s3fwrn5: remove unnecessary label")
  46573e3ab0 ("nfc: s3fwrn5: fix undefined parameter values in dev_err()")
  801e541c79 ("nfc: s3fwrn5: fix undefined parameter values in dev_err()")

MAINTAINERS
  7d901a1e87 ("net: phy: add Maxlinear GPY115/21x/24x driver")
  8a7b46fa79 ("MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-31 09:14:46 -07:00
Wang Hai
121dffe20b mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook()
When I use kfree_rcu() to free a large memory allocated by kmalloc_node(),
the following dump occurs.

  BUG: kernel NULL pointer dereference, address: 0000000000000020
  [...]
  Oops: 0000 [#1] SMP
  [...]
  Workqueue: events kfree_rcu_work
  RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline]
  RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline]
  RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363
  [...]
  Call Trace:
    kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293
    kfree_bulk include/linux/slab.h:413 [inline]
    kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300
    process_one_work+0x207/0x530 kernel/workqueue.c:2276
    worker_thread+0x320/0x610 kernel/workqueue.c:2422
    kthread+0x13d/0x160 kernel/kthread.c:313
    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

When kmalloc_node() a large memory, page is allocated, not slab, so when
freeing memory via kfree_rcu(), this large memory should not be used by
memcg_slab_free_hook(), because memcg_slab_free_hook() is is used for
slab.

Using page_objcgs_check() instead of page_objcgs() in
memcg_slab_free_hook() to fix this bug.

Link: https://lkml.kernel.org/r/20210728145655.274476-1-wanghai38@huawei.com
Fixes: 270c6a7146 ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data")
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-30 10:14:39 -07:00
Shakeel Butt
f227f0faf6 slub: fix unreclaimable slab stat for bulk free
SLUB uses page allocator for higher order allocations and update
unreclaimable slab stat for such allocations.  At the moment, the bulk
free for SLUB does not share code with normal free code path for these
type of allocations and have missed the stat update.  So, fix the stat
update by common code.  The user visible impact of the bug is the
potential of inconsistent unreclaimable slab stat visible through
meminfo and vmstat.

Link: https://lkml.kernel.org/r/20210728155354.3440560-1-shakeelb@google.com
Fixes: 6a486c0ad4 ("mm, sl[ou]b: improve memory accounting")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-30 10:14:39 -07:00
Aneesh Kumar K.V
b5916c0254 mm/migrate: fix NR_ISOLATED corruption on 64-bit
Similar to commit 2da9f6305f ("mm/vmscan: fix NR_ISOLATED_FILE
corruption on 64-bit") avoid using unsigned int for nr_pages.  With
unsigned int type the large unsigned int converts to a large positive
signed long.

Symptoms include CMA allocations hanging forever due to
alloc_contig_range->...->isolate_migratepages_block waiting forever in
"while (unlikely(too_many_isolated(pgdat)))".

Link: https://lkml.kernel.org/r/20210728042531.359409-1-aneesh.kumar@linux.ibm.com
Fixes: c5fc5c3ae0 ("mm: migrate: account THP NUMA migration counters correctly")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-30 10:14:39 -07:00
Johannes Weiner
30def93565 mm: memcontrol: fix blocking rstat function called from atomic cgroup1 thresholding code
Dan Carpenter reports:

    The patch 2d146aa3aa: "mm: memcontrol: switch to rstat" from Apr
    29, 2021, leads to the following static checker warning:

	    kernel/cgroup/rstat.c:200 cgroup_rstat_flush()
	    warn: sleeping in atomic context

    mm/memcontrol.c
      3572  static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
      3573  {
      3574          unsigned long val;
      3575
      3576          if (mem_cgroup_is_root(memcg)) {
      3577                  cgroup_rstat_flush(memcg->css.cgroup);
			    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    This is from static analysis and potentially a false positive.  The
    problem is that mem_cgroup_usage() is called from __mem_cgroup_threshold()
    which holds an rcu_read_lock().  And the cgroup_rstat_flush() function
    can sleep.

      3578                  val = memcg_page_state(memcg, NR_FILE_PAGES) +
      3579                          memcg_page_state(memcg, NR_ANON_MAPPED);
      3580                  if (swap)
      3581                          val += memcg_page_state(memcg, MEMCG_SWAP);
      3582          } else {
      3583                  if (!swap)
      3584                          val = page_counter_read(&memcg->memory);
      3585                  else
      3586                          val = page_counter_read(&memcg->memsw);
      3587          }
      3588          return val;
      3589  }

__mem_cgroup_threshold() indeed holds the rcu lock.  In addition, the
thresholding code is invoked during stat changes, and those contexts
have irqs disabled as well.  If the lock breaking occurs inside the
flush function, it will result in a sleep from an atomic context.

Use the irqsafe flushing variant in mem_cgroup_usage() to fix this.

Link: https://lkml.kernel.org/r/20210726150019.251820-1-hannes@cmpxchg.org
Fixes: 2d146aa3aa ("mm: memcontrol: switch to rstat")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-30 10:14:39 -07:00
Sven Schnelle
f99e12b21b kfence: add function to mask address bits
s390 only reports the page address during a translation fault.
To make the kfence unit tests pass, add a function that might
be implemented by architectures to mask out address bits.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20210728190254.3921642-3-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-30 17:09:01 +02:00
Qi Zheng
e4dc348914 mm: fix the deadlock in finish_fault()
Commit 63f3655f95 ("mm, memcg: fix reclaim deadlock with writeback")
fix the following ABBA deadlock by pre-allocating the pte page table
without holding the page lock.

	                                lock_page(A)
                                        SetPageWriteback(A)
                                        unlock_page(A)
  lock_page(B)
                                        lock_page(B)
  pte_alloc_one
    shrink_page_list
      wait_on_page_writeback(A)
                                        SetPageWriteback(B)
                                        unlock_page(B)

                                        # flush A, B to clear the writeback

Commit f9ce0be71d ("mm: Cleanup faultaround and finish_fault()
codepaths") reworked the relevant code but ignored this race.  This will
cause the deadlock above to appear again, so fix it.

Link: https://lkml.kernel.org/r/20210721074849.57004-1-zhengqi.arch@bytedance.com
Fixes: f9ce0be71d ("mm: Cleanup faultaround and finish_fault() codepaths")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Muchun Song
e904c2ccf9 mm: mmap_lock: fix disabling preemption directly
Commit 832b507253 ("mm: mmap_lock: use local locks instead of
disabling preemption") fixed a bug by using local locks.

But commit d01079f3d0 ("mm/mmap_lock: remove dead code for
!CONFIG_TRACING configurations") changed those lines back to the
original version.

I guess it was introduced by fixing conflicts.

Link: https://lkml.kernel.org/r/20210720074228.76342-1-songmuchun@bytedance.com
Fixes: d01079f3d0 ("mm/mmap_lock: remove dead code for !CONFIG_TRACING configurations")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Mike Rapoport
af64237461 mm/secretmem: wire up ->set_page_dirty
Make secretmem up to date with the changes done in commit 0af573780b
("mm: require ->set_page_dirty to be explicitly wired up") so that
unconditional call to this method won't cause crashes.

Link: https://lkml.kernel.org/r/20210716063933.31633-1-rppt@kernel.org
Fixes: 0af573780b ("mm: require ->set_page_dirty to be explicitly wired up")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Roman Gushchin
b43a9e76b4 writeback, cgroup: remove wb from offline list before releasing refcnt
Boyang reported that the commit c22d70a162 ("writeback, cgroup:
release dying cgwbs by switching attached inodes") causes the kernel to
crash while running xfstests generic/256 on ext4 on aarch64 and ppc64le.

  run fstests generic/256 at 2021-07-12 05:41:40
  EXT4-fs (vda3): mounted filesystem with ordered data mode. Opts: . Quota mode: none.
  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
  Mem abort info:
     ESR = 0x96000005
     EC = 0x25: DABT (current EL), IL = 32 bits
     SET = 0, FnV = 0
     EA = 0, S1PTW = 0
     FSC = 0x05: level 1 translation fault
  Data abort info:
     ISV = 0, ISS = 0x00000005
     CM = 0, WnR = 0
  user pgtable: 64k pages, 48-bit VAs, pgdp=00000000b0502000
  [0000000000000000] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
  Internal error: Oops: 96000005 [#1] SMP
  Modules linked in: dm_flakey dm_snapshot dm_bufio dm_zero dm_mod loop tls rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs rfkill sunrpc ext4 vfat fat mbcache jbd2 drm fuse xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce virtio_blk virtio_net net_failover virtio_console failover virtio_mmio aes_neon_bs [last unloaded: scsi_debug]
  CPU: 0 PID: 408468 Comm: kworker/u8:5 Tainted: G X --------- ---  5.14.0-0.rc1.15.bx.el9.aarch64 #1
  Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
  Workqueue: events_unbound cleanup_offline_cgwbs_workfn
  pstate: 004000c5 (nzcv daIF +PAN -UAO -TCO BTYPE=--)
  pc : cleanup_offline_cgwbs_workfn+0x320/0x394
  lr : cleanup_offline_cgwbs_workfn+0xe0/0x394
  sp : ffff80001554fd10
  x29: ffff80001554fd10 x28: 0000000000000000 x27: 0000000000000001
  x26: 0000000000000000 x25: 00000000000000e0 x24: ffffd2a2fbe671a8
  x23: ffff80001554fd88 x22: ffffd2a2fbe67198 x21: ffffd2a2fc25a730
  x20: ffff210412bc3000 x19: ffff210412bc3280 x18: 0000000000000000
  x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
  x14: 0000000000000000 x13: 0000000000000030 x12: 0000000000000040
  x11: ffff210481572238 x10: ffff21048157223a x9 : ffffd2a2fa276c60
  x8 : ffff210484106b60 x7 : 0000000000000000 x6 : 000000000007d18a
  x5 : ffff210416a86400 x4 : ffff210412bc0280 x3 : 0000000000000000
  x2 : ffff80001554fd88 x1 : ffff210412bc0280 x0 : 0000000000000003
  Call trace:
     cleanup_offline_cgwbs_workfn+0x320/0x394
     process_one_work+0x1f4/0x4b0
     worker_thread+0x184/0x540
     kthread+0x114/0x120
     ret_from_fork+0x10/0x18
  Code: d63f0020 97f99963 17ffffa6 f8588263 (f9400061)
  ---[ end trace e250fe289272792a ]---
  Kernel panic - not syncing: Oops: Fatal exception
  SMP: stopping secondary CPUs
  SMP: failed to stop secondary CPUs 0-2
  Kernel Offset: 0x52a2e9fa0000 from 0xffff800010000000
  PHYS_OFFSET: 0xfff0defca0000000
  CPU features: 0x00200251,23200840
  Memory Limit: none
  ---[ end Kernel panic - not syncing: Oops: Fatal exception ]---

The problem happens when cgwb_release_workfn() races with
cleanup_offline_cgwbs_workfn(): wb_tryget() in
cleanup_offline_cgwbs_workfn() can be called after percpu_ref_exit() is
cgwb_release_workfn(), which is basically a use-after-free error.

Fix the problem by making removing the writeback structure from the
offline list before releasing the percpu reference counter.  It will
guarantee that cleanup_offline_cgwbs_workfn() will not see and not
access writeback structures which are about to be released.

Link: https://lkml.kernel.org/r/20210716201039.3762203-1-guro@fb.com
Fixes: c22d70a162 ("writeback, cgroup: release dying cgwbs by switching attached inodes")
Signed-off-by: Roman Gushchin <guro@fb.com>
Reported-by: Boyang Xue <bxue@redhat.com>
Suggested-by: Jan Kara <jack@suse.cz>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Mike Rapoport
79e482e9c3 memblock: make for_each_mem_range() traverse MEMBLOCK_HOTPLUG regions
Commit b10d6bca87 ("arch, drivers: replace for_each_membock() with
for_each_mem_range()") didn't take into account that when there is
movable_node parameter in the kernel command line, for_each_mem_range()
would skip ranges marked with MEMBLOCK_HOTPLUG.

The page table setup code in POWER uses for_each_mem_range() to create
the linear mapping of the physical memory and since the regions marked
as MEMORY_HOTPLUG are skipped, they never make it to the linear map.

A later access to the memory in those ranges will fail:

  BUG: Unable to handle kernel data access on write at 0xc000000400000000
  Faulting instruction address: 0xc00000000008a3c0
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 0 PID: 53 Comm: kworker/u2:0 Not tainted 5.13.0 #7
  NIP:  c00000000008a3c0 LR: c0000000003c1ed8 CTR: 0000000000000040
  REGS: c000000008a57770 TRAP: 0300   Not tainted  (5.13.0)
  MSR:  8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 84222202  XER: 20040000
  CFAR: c0000000003c1ed4 DAR: c000000400000000 DSISR: 42000000 IRQMASK: 0
  GPR00: c0000000003c1ed8 c000000008a57a10 c0000000019da700 c000000400000000
  GPR04: 0000000000000280 0000000000000180 0000000000000400 0000000000000200
  GPR08: 0000000000000100 0000000000000080 0000000000000040 0000000000000300
  GPR12: 0000000000000380 c000000001bc0000 c0000000001660c8 c000000006337e00
  GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR20: 0000000040000000 0000000020000000 c000000001a81990 c000000008c30000
  GPR24: c000000008c20000 c000000001a81998 000fffffffff0000 c000000001a819a0
  GPR28: c000000001a81908 c00c000001000000 c000000008c40000 c000000008a64680
  NIP clear_user_page+0x50/0x80
  LR __handle_mm_fault+0xc88/0x1910
  Call Trace:
    __handle_mm_fault+0xc44/0x1910 (unreliable)
    handle_mm_fault+0x130/0x2a0
    __get_user_pages+0x248/0x610
    __get_user_pages_remote+0x12c/0x3e0
    get_arg_page+0x54/0xf0
    copy_string_kernel+0x11c/0x210
    kernel_execve+0x16c/0x220
    call_usermodehelper_exec_async+0x1b0/0x2f0
    ret_from_kernel_thread+0x5c/0x70
  Instruction dump:
  79280fa4 79271764 79261f24 794ae8e2 7ca94214 7d683a14 7c893a14 7d893050
  7d4903a6 60000000 60000000 60000000 <7c001fec> 7c091fec 7c081fec 7c051fec
  ---[ end trace 490b8c67e6075e09 ]---

Making for_each_mem_range() include MEMBLOCK_HOTPLUG regions in the
traversal fixes this issue.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1976100
Link: https://lkml.kernel.org/r/20210712071132.20902-1-rppt@kernel.org
Fixes: b10d6bca87 ("arch, drivers: replace for_each_membock() with for_each_mem_range()")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>	[5.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Sergei Trofimovich
69e5d322a2 mm: page_alloc: fix page_poison=1 / INIT_ON_ALLOC_DEFAULT_ON interaction
To reproduce the failure we need the following system:

 - kernel command: page_poison=1 init_on_free=0 init_on_alloc=0

 - kernel config:
    * CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y
    * CONFIG_INIT_ON_FREE_DEFAULT_ON=y
    * CONFIG_PAGE_POISONING=y

Resulting in:

    0000000085629bdd: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    0000000022861832: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00000000c597f5b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    CPU: 11 PID: 15195 Comm: bash Kdump: loaded Tainted: G     U     O      5.13.1-gentoo-x86_64 #1
    Hardware name: System manufacturer System Product Name/PRIME Z370-A, BIOS 2801 01/13/2021
    Call Trace:
     dump_stack+0x64/0x7c
     __kernel_unpoison_pages.cold+0x48/0x84
     post_alloc_hook+0x60/0xa0
     get_page_from_freelist+0xdb8/0x1000
     __alloc_pages+0x163/0x2b0
     __get_free_pages+0xc/0x30
     pgd_alloc+0x2e/0x1a0
     mm_init+0x185/0x270
     dup_mm+0x6b/0x4f0
     copy_process+0x190d/0x1b10
     kernel_clone+0xba/0x3b0
     __do_sys_clone+0x8f/0xb0
     do_syscall_64+0x68/0x80
     entry_SYSCALL_64_after_hwframe+0x44/0xae

Before commit 51cba1ebc6 ("init_on_alloc: Optimize static branches")
init_on_alloc never enabled static branch by default.  It could only be
enabed explicitly by init_mem_debugging_and_hardening().

But after commit 51cba1ebc6, a static branch could already be enabled
by default.  There was no code to ever disable it.  That caused
page_poison=1 / init_on_free=1 conflict.

This change extends init_mem_debugging_and_hardening() to also disable
static branch disabling.

Link: https://lkml.kernel.org/r/20210714031935.4094114-1-keescook@chromium.org
Link: https://lore.kernel.org/r/20210712215816.1512739-1-slyfox@gentoo.org
Fixes: 51cba1ebc6 ("init_on_alloc: Optimize static branches")
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Kees Cook <keescook@chromium.org>
Reported-by: Mikhail Morfikov <mmorfikov@gmail.com>
Reported-by: <bowsingbetee@pm.me>
Tested-by: <bowsingbetee@protonmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Alexander Potapenko
236e9f1538 kfence: skip all GFP_ZONEMASK allocations
Allocation requests outside ZONE_NORMAL (MOVABLE, HIGHMEM or DMA) cannot
be fulfilled by KFENCE, because KFENCE memory pool is located in a zone
different from the requested one.

Because callers of kmem_cache_alloc() may actually rely on the
allocation to reside in the requested zone (e.g.  memory allocations
done with __GFP_DMA must be DMAable), skip all allocations done with
GFP_ZONEMASK and/or respective SLAB flags (SLAB_CACHE_DMA and
SLAB_CACHE_DMA32).

Link: https://lkml.kernel.org/r/20210714092222.1890268-2-glider@google.com
Fixes: 0ce20dd840 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: <stable@vger.kernel.org>	[5.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Alexander Potapenko
235a85cb32 kfence: move the size check to the beginning of __kfence_alloc()
Check the allocation size before toggling kfence_allocation_gate.

This way allocations that can't be served by KFENCE will not result in
waiting for another CONFIG_KFENCE_SAMPLE_INTERVAL without allocating
anything.

Link: https://lkml.kernel.org/r/20210714092222.1890268-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>	[5.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
Weizhao Ouyang
32ae8a0669 kfence: defer kfence_test_init to ensure that kunit debugfs is created
kfence_test_init and kunit_init both use the same level late_initcall,
which means if kfence_test_init linked ahead of kunit_init,
kfence_test_init will get a NULL debugfs_rootdir as parent dentry, then
kfence_test_init and kfence_debugfs_init both create a debugfs node
named "kfence" under debugfs_mount->mnt_root, and it will throw out
"debugfs: Directory 'kfence' with parent '/' already present!" with
EEXIST.  So kfence_test_init should be deferred.

Link: https://lkml.kernel.org/r/20210714113140.2949995-1-o451686892@gmail.com
Signed-off-by: Weizhao Ouyang <o451686892@gmail.com>
Tested-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23 17:43:28 -07:00
David S. Miller
5af84df962 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts are simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-23 16:13:06 +01:00
Vasily Averin
6126891c6d memcg: enable accounting for IP address and routing-related objects
An netadmin inside container can use 'ip a a' and 'ip r a'
to assign a large number of ipv4/ipv6 addresses and routing entries
and force kernel to allocate megabytes of unaccounted memory
for long-lived per-netdevice related kernel objects:
'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node',
'struct rt6_info', 'struct fib_rules' and ip_fib caches.

These objects can be manually removed, though usually they lives
in memory till destroy of its net namespace.

It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.

One of such objects is the 'struct fib6_node' mostly allocated in
net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section:

 write_lock_bh(&table->tb6_lock);
 err = fib6_add(&table->tb6_root, rt, info, mxc);
 write_unlock_bh(&table->tb6_lock);

In this case it is not enough to simply add SLAB_ACCOUNT to corresponding
kmem cache. The proper memory cgroup still cannot be found due to the
incorrect 'in_interrupt()' check used in memcg_kmem_bypass().

Obsoleted in_interrupt() does not describe real execution context properly.
>From include/linux/preempt.h:

 The following macros are deprecated and should not be used in new code:
 in_interrupt()	- We're in NMI,IRQ,SoftIRQ context or have BH disabled

To verify the current execution context new macro should be used instead:
 in_task()	- We're in task context

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-20 06:00:38 -07:00
Linus Torvalds
ae14c63a9f Revert "mm/slub: use stackdepot to save stack trace in objects"
This reverts commit 788691464c.

It's not clear why, but it causes unexplained problems in entirely
unrelated xfs code.  The most likely explanation is some slab
corruption, possibly triggered due to CONFIG_SLUB_DEBUG_ON.  See [1].

It ends up having a few other problems too, like build errors on
arch/arc, and Geert reporting it using much more memory on m68k [3] (it
probably does so elsewhere too, but it is probably just more noticeable
on m68k).

The architecture issues (both build and memory use) are likely just
because this change effectively force-enabled STACKDEPOT (along with a
very bad default value for the stackdepot hash size).  But together with
the xfs issue, this all smells like "this commit was not ready" to me.

Link: https://lore.kernel.org/linux-xfs/YPE3l82acwgI2OiV@infradead.org/ [1]
Link: https://lore.kernel.org/lkml/202107150600.LkGNb4Vb-lkp@intel.com/ [2]
Link: https://lore.kernel.org/lkml/CAMuHMdW=eoVzM1Re5FVoEN87nKfiLmM2+Ah7eNu2KXEhCvbZyA@mail.gmail.com/ [3]
Reported-by: Christoph Hellwig <hch@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-17 13:27:00 -07:00
Joao Martins
d08af0a596 mm/hugetlb: fix refs calculation from unaligned @vaddr
Commit 82e5d378b0 ("mm/hugetlb: refactor subpage recording")
refactored the count of subpages but missed an edge case when @vaddr is
not aligned to PAGE_SIZE e.g.  when close to vma->vm_end.  It would then
errousnly set @refs to 0 and record_subpages_vmas() wouldn't set the
@pages array element to its value, consequently causing the reported
null-deref by syzbot.

Fix it by aligning down @vaddr by PAGE_SIZE in @refs calculation.

Link: https://lkml.kernel.org/r/20210713152440.28650-1-joao.m.martins@oracle.com
Fixes: 82e5d378b0 ("mm/hugetlb: refactor subpage recording")
Reported-by: syzbot+a3fcd59df1b372066f5a@syzkaller.appspotmail.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15 10:13:49 -07:00
Chuck Lever
061478438d mm/page_alloc: further fix __alloc_pages_bulk() return value
The author of commit b3b64ebd38 ("mm/page_alloc: do bulk array
bounds check after checking populated elements") was possibly
confused by the mixture of return values throughout the function.

The API contract is clear that the function "Returns the number of pages
on the list or array." It does not list zero as a unique return value with
a special meaning.  Therefore zero is a plausible return value only if
@nr_pages is zero or less.

Clean up the return logic to make it clear that the returned value is
always the total number of pages in the array/list, not the number of
pages that were allocated during this call.

The only change in behavior with this patch is the value returned if
prepare_alloc_pages() fails.  To match the API contract, the number of
pages currently in the array/list is returned in this case.

The call site in __page_pool_alloc_pages_slow() also seems to be confused
on this matter.  It should be attended to by someone who is familiar with
that code.

[mel@techsingularity.net: Return nr_populated if 0 pages are requested]

Link: https://lkml.kernel.org/r/20210713152100.10381-4-mgorman@techsingularity.net
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Cc: Zhang Qiang <Qiang.Zhang@windriver.com>
Cc: Yanfei Xu <yanfei.xu@windriver.com>
Cc: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15 10:13:49 -07:00
Yanfei Xu
e5c15cea33 mm/page_alloc: correct return value when failing at preparing
If the array passed in is already partially populated, we should return
"nr_populated" even failing at preparing arguments stage.

Link: https://lkml.kernel.org/r/20210713152100.10381-3-mgorman@techsingularity.net
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/20210709102855.55058-1-yanfei.xu@windriver.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15 10:13:49 -07:00
Mel Gorman
187ad460b8 mm/page_alloc: avoid page allocator recursion with pagesets.lock held
Syzbot is reporting potential deadlocks due to pagesets.lock when
PAGE_OWNER is enabled.  One example from Desmond Cheong Zhi Xi is as
follows

  __alloc_pages_bulk()
    local_lock_irqsave(&pagesets.lock, flags) <---- outer lock here
    prep_new_page():
      post_alloc_hook():
        set_page_owner():
          __set_page_owner():
            save_stack():
              stack_depot_save():
                alloc_pages():
                  alloc_page_interleave():
                    __alloc_pages():
                      get_page_from_freelist():
                        rm_queue():
                          rm_queue_pcplist():
                            local_lock_irqsave(&pagesets.lock, flags);
                            *** DEADLOCK ***

Zhang, Qiang also reported

  BUG: sleeping function called from invalid context at mm/page_alloc.c:5179
  in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
  .....
  __dump_stack lib/dump_stack.c:79 [inline]
  dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:96
  ___might_sleep.cold+0x1f1/0x237 kernel/sched/core.c:9153
  prepare_alloc_pages+0x3da/0x580 mm/page_alloc.c:5179
  __alloc_pages+0x12f/0x500 mm/page_alloc.c:5375
  alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2147
  alloc_pages+0x238/0x2a0 mm/mempolicy.c:2270
  stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303
  save_stack+0x15e/0x1e0 mm/page_owner.c:120
  __set_page_owner+0x50/0x290 mm/page_owner.c:181
  prep_new_page mm/page_alloc.c:2445 [inline]
  __alloc_pages_bulk+0x8b9/0x1870 mm/page_alloc.c:5313
  alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline]
  vm_area_alloc_pages mm/vmalloc.c:2775 [inline]
  __vmalloc_area_node mm/vmalloc.c:2845 [inline]
  __vmalloc_node_range+0x39d/0x960 mm/vmalloc.c:2947
  __vmalloc_node mm/vmalloc.c:2996 [inline]
  vzalloc+0x67/0x80 mm/vmalloc.c:3066

There are a number of ways it could be fixed.  The page owner code could
be audited to strip GFP flags that allow sleeping but it'll impair the
functionality of PAGE_OWNER if allocations fail.  The bulk allocator could
add a special case to release/reacquire the lock for prep_new_page and
lookup PCP after the lock is reacquired at the cost of performance.  The
pages requiring prep could be tracked using the least significant bit and
looping through the array although it is more complicated for the list
interface.  The options are relatively complex and the second one still
incurs a performance penalty when PAGE_OWNER is active so this patch takes
the simple approach -- disable bulk allocation of PAGE_OWNER is active.
The caller will be forced to allocate one page at a time incurring a
performance penalty but PAGE_OWNER is already a performance penalty.

Link: https://lkml.kernel.org/r/20210708081434.GV3840@techsingularity.net
Fixes: dbbee9d5cd ("mm/page_alloc: convert per-cpu list protection to local_lock")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
Reported-by: "Zhang, Qiang" <Qiang.Zhang@windriver.com>
Reported-by: syzbot+127fd7828d6eeb611703@syzkaller.appspotmail.com
Tested-by: syzbot+127fd7828d6eeb611703@syzkaller.appspotmail.com
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15 10:13:49 -07:00
Matteo Croce
54aa386661 Revert "mm/page_alloc: make should_fail_alloc_page() static"
This reverts commit f717309003.

Fix an unresolved symbol error when CONFIG_DEBUG_INFO_BTF=y:

    LD      vmlinux
    BTFIDS  vmlinux
  FAILED unresolved symbol should_fail_alloc_page
  make: *** [Makefile:1199: vmlinux] Error 255
  make: *** Deleting file 'vmlinux'

Link: https://lkml.kernel.org/r/20210708191128.153796-1-mcroce@linux.microsoft.com
Fixes: f717309003 ("mm/page_alloc: make should_fail_alloc_page() static")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15 10:13:49 -07:00
Yee Lee
77a63c69ec kasan: add memzero init for unaligned size at DEBUG
Issue: when SLUB debug is on, hwtag kasan_unpoison() would overwrite the
redzone of object with unaligned size.

An additional memzero_explicit() path is added to replacing init by hwtag
instruction for those unaligned size at SLUB debug mode.

The penalty is acceptable since they are only enabled in debug mode, not
production builds.  A block of comment is added for explanation.

Link: https://lkml.kernel.org/r/20210705103229.8505-3-yee.lee@mediatek.com
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
Suggested-by: Andrey Konovalov <andreyknvl@gmail.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15 10:13:49 -07:00
Marco Elver
0d4a062af2 mm: move helper to check slub_debug_enabled
Move the helper to check slub_debug_enabled, so that we can confine the
use of #ifdef outside slub.c as well.

Link: https://lkml.kernel.org/r/20210705103229.8505-2-yee.lee@mediatek.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Yee Lee <yee.lee@mediatek.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-15 10:13:49 -07:00
Jan Kara
7506ae6a70 mm: Add functions to lock invalidate_lock for two mappings
Some operations such as reflinking blocks among files will need to lock
invalidate_lock for two mappings. Add helper functions to do that.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-13 14:29:00 +02:00
Jan Kara
730633f0b7 mm: Protect operations adding pages to page cache with invalidate_lock
Currently, serializing operations such as page fault, read, or readahead
against hole punching is rather difficult. The basic race scheme is
like:

fallocate(FALLOC_FL_PUNCH_HOLE)			read / fault / ..
  truncate_inode_pages_range()
						  <create pages in page
						   cache here>
  <update fs block mapping and free blocks>

Now the problem is in this way read / page fault / readahead can
instantiate pages in page cache with potentially stale data (if blocks
get quickly reused). Avoiding this race is not simple - page locks do
not work because we want to make sure there are *no* pages in given
range. inode->i_rwsem does not work because page fault happens under
mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes
the performance for mixed read-write workloads suffer.

So create a new rw_semaphore in the address_space - invalidate_lock -
that protects adding of pages to page cache for page faults / reads /
readahead.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-13 13:14:27 +02:00
Matthew Wilcox (Oracle)
79789db03f mm: Make copy_huge_page() always available
Rewrite copy_huge_page() and move it into mm/util.c so it's always
available.  Fixes an exposure of uninitialised memory on configurations
with HUGETLB and UFFD enabled and MIGRATION disabled.

Fixes: 8cc5fcbb5b ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-12 11:30:56 -07:00
Hugh Dickins
efdb6720b4 mm/rmap: fix munlocking Anon THP with mlocked ptes
Many thanks to Kirill for reminding that PageDoubleMap cannot be relied on
to warn of pte mappings in the Anon THP case; and a scan of subpages does
not seem appropriate here.  Note how follow_trans_huge_pmd() does not even
mark an Anon THP as mlocked when compound_mapcount != 1: multiple mlocking
of Anon THP is avoided, so simply return from page_mlock() in this case.

Link: https://lore.kernel.org/lkml/cfa154c-d595-406-eb7d-eb9df730f944@google.com/
Fixes: d9770fcc1c ("mm/rmap: fix old bug: munlocking THP missed other mlocks")
Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-12 11:30:56 -07:00
Jan Kara
9608703e48 mm: Fix comments mentioning i_mutex
inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-12 18:31:16 +02:00
Hugh Dickins
6c855fce2e mm/rmap: try_to_migrate() skip zone_device !device_private
I know nothing about zone_device pages and !device_private pages; but if
try_to_migrate_one() will do nothing for them, then it's better that
try_to_migrate() filter them first, than trawl through all their vmas.

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Link: https://lore.kernel.org/lkml/1241d356-8ec9-f47b-a5ec-9b2bf66d242@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-11 15:05:15 -07:00
Hugh Dickins
023e1a8dd5 mm/rmap: fix new bug: premature return from page_mlock_one()
In the unlikely race case that page_mlock_one() finds VM_LOCKED has been
cleared by the time it got page table lock, page_vma_mapped_walk_done()
must be called before returning, either explicitly, or by a final call
to page_vma_mapped_walk() - otherwise the page table remains locked.

Fixes: cd62734ca6 ("mm/rmap: split try_to_munlock from try_to_unmap")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/20210711151446.GB4070@xsang-OptiPlex-9020/
Link: https://lore.kernel.org/lkml/f71f8523-cba7-3342-40a7-114abc5d1f51@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-11 15:05:15 -07:00
Hugh Dickins
d9770fcc1c mm/rmap: fix old bug: munlocking THP missed other mlocks
The kernel recovers in due course from missing Mlocked pages: but there
was no point in calling page_mlock() (formerly known as
try_to_munlock()) on a THP, because nothing got done even when it was
found to be mapped in another VM_LOCKED vma.

It's true that we need to be careful: Mlocked accounting of pte-mapped
THPs is too difficult (so consistently avoided); but Mlocked accounting
of only-pmd-mapped THPs is supposed to work, even when multiple mappings
are mlocked and munlocked or munmapped.  Refine the tests.

There is already a VM_BUG_ON_PAGE(PageDoubleMap) in page_mlock(), so
page_mlock_one() does not even have to worry about that complication.

(I said the kernel recovers: but would page reclaim be likely to split
THP before rediscovering that it's VM_LOCKED? I've not followed that up)

Fixes: 9a73f61bdb ("thp, mlock: do not mlock PTE-mapped file huge pages")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Link: https://lore.kernel.org/lkml/cfa154c-d595-406-eb7d-eb9df730f944@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-11 15:05:15 -07:00
Hugh Dickins
64b586d192 mm/rmap: fix comments left over from recent changes
Parallel developments in mm/rmap.c have left behind some out-of-date
comments: try_to_migrate_one() also accepts TTU_SYNC (already commented
in try_to_migrate() itself), and try_to_migrate() returns nothing at
all.

TTU_SPLIT_FREEZE has just been deleted, so reword the comment about it
in mm/huge_memory.c; and TTU_IGNORE_ACCESS was removed in 5.11, so
delete the "recently referenced" comment from try_to_unmap_one() (once
upon a time the comment was near the removed codeblock, but they drifted
apart).

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Link: https://lore.kernel.org/lkml/563ce5b2-7a44-5b4d-1dfd-59a0e65932a9@google.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-11 15:05:15 -07:00
Mel Gorman
6bce244390 mm/page_alloc: Revert pahole zero-sized workaround
Commit dbbee9d5cd ("mm/page_alloc: convert per-cpu list protection to
local_lock") folded in a workaround patch for pahole that was unable to
deal with zero-sized percpu structures.

A superior workaround is achieved with commit a0b8200d06 ("kbuild:
skip per-CPU BTF generation for pahole v1.18-v1.21").

This patch reverts the dummy field and the pahole version check.

Fixes: dbbee9d5cd ("mm/page_alloc: convert per-cpu list protection to local_lock")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-10 16:09:39 -07:00
Linus Torvalds
20d5e570ae Merge branch 'for-5.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu
Pull percpu fix from Dennis Zhou:
 "This is just a single change to fix percpu depopulation. The code
  relied on depopulation code written specifically for the free path and
  relied on vmalloc to do the tlb flush lazily. As we're modifying the
  backing pages during the lifetime of a chunk, we need to also flush
  the tlb accordingly.

  Guenter Roeck reported this issue in [1] on mips. I believe we just
  happen to be lucky given the much larger chunk sizes on x86 and
  consequently less churning of this memory"

Link: https://lore.kernel.org/lkml/20210702191140.GA3166599@roeck-us.net/ [1]

* 'for-5.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  percpu: flush tlb in pcpu_reclaim_populated()
2021-07-10 09:06:41 -07:00
Aneesh Kumar K.V
3bbda69c48 mm/mremap: allow arch runtime override
Patch series "Speedup mremap on ppc64", v8.

This patchset enables MOVE_PMD/MOVE_PUD support on power.  This requires
the platform to support updating higher-level page tables without updating
page table entries.  This also needs to invalidate the Page Walk Cache on
architecture supporting the same.

This patch (of 3):

Architectures like ppc64 support faster mremap only with radix
translation.  Hence allow a runtime check w.r.t support for fast mremap.

Link: https://lkml.kernel.org/r/20210616045735.374532-1-aneesh.kumar@linux.ibm.com
Link: https://lkml.kernel.org/r/20210616045735.374532-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:23 -07:00
Aneesh Kumar K.V
97113eb39f mm/mremap: hold the rmap lock in write mode when moving page table entries.
To avoid a race between rmap walk and mremap, mremap does
take_rmap_locks().  The lock was taken to ensure that rmap walk don't miss
a page table entry due to PTE moves via move_pagetables().  The kernel
does further optimization of this lock such that if we are going to find
the newly added vma after the old vma, the rmap lock is not taken.  This
is because rmap walk would find the vmas in the same order and if we don't
find the page table attached to older vma we would find it with the new
vma which we would iterate later.

As explained in commit eb66ae0308 ("mremap: properly flush TLB before
releasing the page") mremap is special in that it doesn't take ownership
of the page.  The optimized version for PUD/PMD aligned mremap also
doesn't hold the ptl lock.  This can result in stale TLB entries as show
below.

This patch updates the rmap locking requirement in mremap to handle the race condition
explained below with optimized mremap::

Optmized PMD move

    CPU 1                           CPU 2                                   CPU 3

    mremap(old_addr, new_addr)      page_shrinker/try_to_unmap_one

    mmap_write_lock_killable()

                                    addr = old_addr
                                    lock(pte_ptl)
    lock(pmd_ptl)
    pmd = *old_pmd
    pmd_clear(old_pmd)
    flush_tlb_range(old_addr)

    *new_pmd = pmd
                                                                            *new_addr = 10; and fills
                                                                            TLB with new addr
                                                                            and old pfn

    unlock(pmd_ptl)
                                    ptep_clear_flush()
                                    old pfn is free.
                                                                            Stale TLB entry

Optimized PUD move also suffers from a similar race.  Both the above race
condition can be fixed if we force mremap path to take rmap lock.

Link: https://lkml.kernel.org/r/20210616045239.370802-7-aneesh.kumar@linux.ibm.com
Fixes: 2c91bd4a4e ("mm: speed up mremap by 20x on large regions")
Fixes: c49dd34018 ("mm: speedup mremap on 1GB or larger regions")
Link: https://lore.kernel.org/linux-mm/CAHk-=wgXVR04eBNtxQfevontWnP6FDm+oj5vauQXP3S-huwbPw@mail.gmail.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:23 -07:00
Aneesh Kumar K.V
0881ace292 mm/mremap: use pmd/pud_poplulate to update page table entries
pmd/pud_populate is the right interface to be used to set the respective
page table entries.  Some architectures like ppc64 do assume that
set_pmd/pud_at can only be used to set a hugepage PTE.  Since we are not
setting up a hugepage PTE here, use the pmd/pud_populate interface.

Link: https://lkml.kernel.org/r/20210616045239.370802-6-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:23 -07:00
Aneesh Kumar K.V
d6655dff2e mm/mremap: don't enable optimized PUD move if page table levels is 2
With two level page table don't enable move_normal_pud.

Link: https://lkml.kernel.org/r/20210616045239.370802-5-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:23 -07:00
Aneesh Kumar K.V
7d846db7d0 mm/mremap: convert huge PUD move to separate helper
With TRANSPARENT_HUGEPAGE_PUD enabled the kernel can find huge PUD
entries.  Add a helper to move huge PUD entries on mremap().

This will be used by a later patch to optimize mremap of PUD_SIZE aligned
level 4 PTE mapped address

This also make sure we support mremap on huge PUD entries even with
CONFIG_HAVE_MOVE_PUD disabled.

[aneesh.kumar@linux.ibm.com: fix build failure with clang-10]
  Link: https://lore.kernel.org/lkml/YMuOSnJsL9qkxweY@archlinux-ax161
  Link: https://lkml.kernel.org/r/20210619134310.89098-1-aneesh.kumar@linux.ibm.com

Link: https://lkml.kernel.org/r/20210616045239.370802-4-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:23 -07:00
Kefeng Wang
5748fbc533 mm: add setup_initial_init_mm() helper
Patch series "init_mm: cleanup ARCH's text/data/brk setup code", v3.

Add setup_initial_init_mm() helper, then use it to cleanup the text, data
and brk setup code.

This patch (of 15):

Add setup_initial_init_mm() helper to setup kernel text, data and brk.

Link: https://lkml.kernel.org/r/20210608083418.137226-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20210608083418.137226-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:21 -07:00
Mike Rapoport
9a436f8ff6 PM: hibernate: disable when there are active secretmem users
It is unsafe to allow saving of secretmem areas to the hibernation
snapshot as they would be visible after the resume and this essentially
will defeat the purpose of secret memory mappings.

Prevent hibernation whenever there are active secret memory users.

Link: https://lkml.kernel.org/r/20210518072034.31572-6-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Will Deacon <will@kernel.org>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:21 -07:00
Mike Rapoport
1507f51255 mm: introduce memfd_secret system call to create "secret" memory areas
Introduce "memfd_secret" system call with the ability to create memory
areas visible only in the context of the owning process and not mapped not
only to other processes but in the kernel page tables as well.

The secretmem feature is off by default and the user must explicitly
enable it at the boot time.

Once secretmem is enabled, the user will be able to create a file
descriptor using the memfd_secret() system call.  The memory areas created
by mmap() calls from this file descriptor will be unmapped from the kernel
direct map and they will be only mapped in the page table of the processes
that have access to the file descriptor.

Secretmem is designed to provide the following protections:

* Enhanced protection (in conjunction with all the other in-kernel
  attack prevention systems) against ROP attacks.  Seceretmem makes
  "simple" ROP insufficient to perform exfiltration, which increases the
  required complexity of the attack.  Along with other protections like
  the kernel stack size limit and address space layout randomization which
  make finding gadgets is really hard, absence of any in-kernel primitive
  for accessing secret memory means the one gadget ROP attack can't work.
  Since the only way to access secret memory is to reconstruct the missing
  mapping entry, the attacker has to recover the physical page and insert
  a PTE pointing to it in the kernel and then retrieve the contents.  That
  takes at least three gadgets which is a level of difficulty beyond most
  standard attacks.

* Prevent cross-process secret userspace memory exposures.  Once the
  secret memory is allocated, the user can't accidentally pass it into the
  kernel to be transmitted somewhere.  The secreremem pages cannot be
  accessed via the direct map and they are disallowed in GUP.

* Harden against exploited kernel flaws.  In order to access secretmem,
  a kernel-side attack would need to either walk the page tables and
  create new ones, or spawn a new privileged uiserspace process to perform
  secrets exfiltration using ptrace.

The file descriptor based memory has several advantages over the
"traditional" mm interfaces, such as mlock(), mprotect(), madvise().  File
descriptor approach allows explicit and controlled sharing of the memory
areas, it allows to seal the operations.  Besides, file descriptor based
memory paves the way for VMMs to remove the secret memory range from the
userspace hipervisor process, for instance QEMU.  Andy Lutomirski says:

  "Getting fd-backed memory into a guest will take some possibly major
  work in the kernel, but getting vma-backed memory into a guest without
  mapping it in the host user address space seems much, much worse."

memfd_secret() is made a dedicated system call rather than an extension to
memfd_create() because it's purpose is to allow the user to create more
secure memory mappings rather than to simply allow file based access to
the memory.  Nowadays a new system call cost is negligible while it is way
simpler for userspace to deal with a clear-cut system calls than with a
multiplexer or an overloaded syscall.  Moreover, the initial
implementation of memfd_secret() is completely distinct from
memfd_create() so there is no much sense in overloading memfd_create() to
begin with.  If there will be a need for code sharing between these
implementation it can be easily achieved without a need to adjust user
visible APIs.

The secret memory remains accessible in the process context using uaccess
primitives, but it is not exposed to the kernel otherwise; secret memory
areas are removed from the direct map and functions in the
follow_page()/get_user_page() family will refuse to return a page that
belongs to the secret memory area.

Once there will be a use case that will require exposing secretmem to the
kernel it will be an opt-in request in the system call flags so that user
would have to decide what data can be exposed to the kernel.

Removing of the pages from the direct map may cause its fragmentation on
architectures that use large pages to map the physical memory which
affects the system performance.  However, the original Kconfig text for
CONFIG_DIRECT_GBPAGES said that gigabyte pages in the direct map "...  can
improve the kernel's performance a tiny bit ..." (commit 00d1c5e057
("x86: add gbpages switches")) and the recent report [1] showed that "...
although 1G mappings are a good default choice, there is no compelling
evidence that it must be the only choice".  Hence, it is sufficient to
have secretmem disabled by default with the ability of a system
administrator to enable it at boot time.

Pages in the secretmem regions are unevictable and unmovable to avoid
accidental exposure of the sensitive data via swap or during page
migration.

Since the secretmem mappings are locked in memory they cannot exceed
RLIMIT_MEMLOCK.  Since these mappings are already locked independently
from mlock(), an attempt to mlock()/munlock() secretmem range would fail
and mlockall()/munlockall() will ignore secretmem mappings.

However, unlike mlock()ed memory, secretmem currently behaves more like
long-term GUP: secretmem mappings are unmovable mappings directly consumed
by user space.  With default limits, there is no excessive use of
secretmem and it poses no real problem in combination with
ZONE_MOVABLE/CMA, but in the future this should be addressed to allow
balanced use of large amounts of secretmem along with ZONE_MOVABLE/CMA.

A page that was a part of the secret memory area is cleared when it is
freed to ensure the data is not exposed to the next user of that page.

The following example demonstrates creation of a secret mapping (error
handling is omitted):

	fd = memfd_secret(0);
	ftruncate(fd, MAP_SIZE);
	ptr = mmap(NULL, MAP_SIZE, PROT_READ | PROT_WRITE,
		   MAP_SHARED, fd, 0);

[1] https://lore.kernel.org/linux-mm/213b4567-46ce-f116-9cdf-bbd0c884eb3c@linux.intel.com/

[akpm@linux-foundation.org: suppress Kconfig whine]

Link: https://lkml.kernel.org/r/20210518072034.31572-5-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Hagen Paul Pfeifer <hagen@jauu.net>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Will Deacon <will@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:21 -07:00
Mike Rapoport
6aeb25425d mmap: make mlock_future_check() global
Patch series "mm: introduce memfd_secret system call to create "secret" memory areas", v20.

This is an implementation of "secret" mappings backed by a file
descriptor.

The file descriptor backing secret memory mappings is created using a
dedicated memfd_secret system call The desired protection mode for the
memory is configured using flags parameter of the system call.  The mmap()
of the file descriptor created with memfd_secret() will create a "secret"
memory mapping.  The pages in that mapping will be marked as not present
in the direct map and will be present only in the page table of the owning
mm.

Although normally Linux userspace mappings are protected from other users,
such secret mappings are useful for environments where a hostile tenant is
trying to trick the kernel into giving them access to other tenants
mappings.

It's designed to provide the following protections:

* Enhanced protection (in conjunction with all the other in-kernel
  attack prevention systems) against ROP attacks.  Seceretmem makes
  "simple" ROP insufficient to perform exfiltration, which increases the
  required complexity of the attack.  Along with other protections like
  the kernel stack size limit and address space layout randomization which
  make finding gadgets is really hard, absence of any in-kernel primitive
  for accessing secret memory means the one gadget ROP attack can't work.
  Since the only way to access secret memory is to reconstruct the missing
  mapping entry, the attacker has to recover the physical page and insert
  a PTE pointing to it in the kernel and then retrieve the contents.  That
  takes at least three gadgets which is a level of difficulty beyond most
  standard attacks.

* Prevent cross-process secret userspace memory exposures.  Once the
  secret memory is allocated, the user can't accidentally pass it into the
  kernel to be transmitted somewhere.  The secreremem pages cannot be
  accessed via the direct map and they are disallowed in GUP.

* Harden against exploited kernel flaws.  In order to access secretmem,
  a kernel-side attack would need to either walk the page tables and
  create new ones, or spawn a new privileged uiserspace process to perform
  secrets exfiltration using ptrace.

In the future the secret mappings may be used as a mean to protect guest
memory in a virtual machine host.

For demonstration of secret memory usage we've created a userspace library

https://git.kernel.org/pub/scm/linux/kernel/git/jejb/secret-memory-preloader.git

that does two things: the first is act as a preloader for openssl to
redirect all the OPENSSL_malloc calls to secret memory meaning any secret
keys get automatically protected this way and the other thing it does is
expose the API to the user who needs it.  We anticipate that a lot of the
use cases would be like the openssl one: many toolkits that deal with
secret keys already have special handling for the memory to try to give
them greater protection, so this would simply be pluggable into the
toolkits without any need for user application modification.

Hiding secret memory mappings behind an anonymous file allows usage of the
page cache for tracking pages allocated for the "secret" mappings as well
as using address_space_operations for e.g.  page migration callbacks.

The anonymous file may be also used implicitly, like hugetlb files, to
implement mmap(MAP_SECRET) and use the secret memory areas with "native"
mm ABIs in the future.

Removing of the pages from the direct map may cause its fragmentation on
architectures that use large pages to map the physical memory which
affects the system performance.  However, the original Kconfig text for
CONFIG_DIRECT_GBPAGES said that gigabyte pages in the direct map "...  can
improve the kernel's performance a tiny bit ..." (commit 00d1c5e057
("x86: add gbpages switches")) and the recent report [1] showed that "...
although 1G mappings are a good default choice, there is no compelling
evidence that it must be the only choice".  Hence, it is sufficient to
have secretmem disabled by default with the ability of a system
administrator to enable it at boot time.

In addition, there is also a long term goal to improve management of the
direct map.

[1] https://lore.kernel.org/linux-mm/213b4567-46ce-f116-9cdf-bbd0c884eb3c@linux.intel.com/

This patch (of 7):

It will be used by the upcoming secret memory implementation.

Link: https://lkml.kernel.org/r/20210518072034.31572-1-rppt@kernel.org
Link: https://lkml.kernel.org/r/20210518072034.31572-2-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tycho Andersen <tycho@tycho.ws>
Cc: Will Deacon <will@kernel.org>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:20 -07:00
Oliver Glitta
788691464c mm/slub: use stackdepot to save stack trace in objects
Many stack traces are similar so there are many similar arrays.
Stackdepot saves each unique stack only once.

Replace field addrs in struct track with depot_stack_handle_t handle.  Use
stackdepot to save stack trace.

The benefits are smaller memory overhead and possibility to aggregate
per-cache statistics in the future using the stackdepot handle instead of
matching stacks manually.

[rdunlap@infradead.org: rename save_stack_trace()]
  Link: https://lkml.kernel.org/r/20210513051920.29320-1-rdunlap@infradead.org
[vbabka@suse.cz: fix lockdep splat]
  Link: https://lkml.kernel.org/r/20210516195150.26740-1-vbabka@suse.czLink: https://lkml.kernel.org/r/20210414163434.4376-1-glittao@gmail.com

Signed-off-by: Oliver Glitta <glittao@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:20 -07:00
Linus Torvalds
28e92f9903 Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:

 - Bitmap parsing support for "all" as an alias for all bits

 - Documentation updates

 - Miscellaneous fixes, including some that overlap into mm and lockdep

 - kvfree_rcu() updates

 - mem_dump_obj() updates, with acks from one of the slab-allocator
   maintainers

 - RCU NOCB CPU updates, including limited deoffloading

 - SRCU updates

 - Tasks-RCU updates

 - Torture-test updates

* 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits)
  tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline
  rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states
  rcu: Add missing __releases() annotation
  rcu: Remove obsolete rcu_read_unlock() deadlock commentary
  rcu: Improve comments describing RCU read-side critical sections
  rcu: Create an unrcu_pointer() to remove __rcu from a pointer
  srcu: Early test SRCU polling start
  rcu: Fix various typos in comments
  rcu/nocb: Unify timers
  rcu/nocb: Prepare for fine-grained deferred wakeup
  rcu/nocb: Only cancel nocb timer if not polling
  rcu/nocb: Delete bypass_timer upon nocb_gp wakeup
  rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup
  rcu/nocb: Allow de-offloading rdp leader
  rcu/nocb: Directly call __wake_nocb_gp() from bypass timer
  rcu: Don't penalize priority boosting when there is nothing to boost
  rcu: Point to documentation of ordering guarantees
  rcu: Make rcu_gp_cleanup() be noinline for tracing
  rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs
  rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP
  ...
2021-07-04 12:58:33 -07:00
Linus Torvalds
a412897fb5 memblock, arm: fix crashes caused by holes in the memory map
The coordination between freeing of unused memory map, pfn_valid() and core
 mm assumptions about validity of the memory map in various ranges was not
 designed for complex layouts of the physical memory with a lot of holes all
 over the place.
 
 Kefen Wang reported crashes in move_freepages() on a system with the
 following memory layout [1]:
 
   node   0: [mem 0x0000000080a00000-0x00000000855fffff]
   node   0: [mem 0x0000000086a00000-0x0000000087dfffff]
   node   0: [mem 0x000000008bd00000-0x000000008c4fffff]
   node   0: [mem 0x000000008e300000-0x000000008ecfffff]
   node   0: [mem 0x0000000090d00000-0x00000000bfffffff]
   node   0: [mem 0x00000000cc000000-0x00000000dc9fffff]
   node   0: [mem 0x00000000de700000-0x00000000de9fffff]
   node   0: [mem 0x00000000e0800000-0x00000000e0bfffff]
   node   0: [mem 0x00000000f4b00000-0x00000000f6ffffff]
   node   0: [mem 0x00000000fda00000-0x00000000ffffefff]
 
 These crashes can be mitigated by enabling CONFIG_HOLES_IN_ZONE on ARM and
 essentially turning pfn_valid_within() to pfn_valid() instead of having it
 hardwired to 1 on that architecture, but this would require to keep
 CONFIG_HOLES_IN_ZONE solely for this purpose.
 
 A cleaner approach is to update ARM's implementation of pfn_valid() to take
 into accounting rounding of the freed memory map to pageblock boundaries
 and make sure it returns true for PFNs that have memory map entries even if
 there is no physical memory backing those PFNs.
 
 [1] https://lore.kernel.org/lkml/2a1592ad-bc9d-4664-fd19-f7448a37edc0@huawei.com
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Merge tag 'memblock-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock updates from Mike Rapoport:
 "Fix arm crashes caused by holes in the memory map.

  The coordination between freeing of unused memory map, pfn_valid() and
  core mm assumptions about validity of the memory map in various ranges
  was not designed for complex layouts of the physical memory with a lot
  of holes all over the place.

  Kefen Wang reported crashes in move_freepages() on a system with the
  following memory layout [1]:

	node 0: [mem 0x0000000080a00000-0x00000000855fffff]
	node 0: [mem 0x0000000086a00000-0x0000000087dfffff]
	node 0: [mem 0x000000008bd00000-0x000000008c4fffff]
	node 0: [mem 0x000000008e300000-0x000000008ecfffff]
	node 0: [mem 0x0000000090d00000-0x00000000bfffffff]
	node 0: [mem 0x00000000cc000000-0x00000000dc9fffff]
	node 0: [mem 0x00000000de700000-0x00000000de9fffff]
	node 0: [mem 0x00000000e0800000-0x00000000e0bfffff]
	node 0: [mem 0x00000000f4b00000-0x00000000f6ffffff]
	node 0: [mem 0x00000000fda00000-0x00000000ffffefff]

  These crashes can be mitigated by enabling CONFIG_HOLES_IN_ZONE on ARM
  and essentially turning pfn_valid_within() to pfn_valid() instead of
  having it hardwired to 1 on that architecture, but this would require
  to keep CONFIG_HOLES_IN_ZONE solely for this purpose.

  A cleaner approach is to update ARM's implementation of pfn_valid() to
  take into accounting rounding of the freed memory map to pageblock
  boundaries and make sure it returns true for PFNs that have memory map
  entries even if there is no physical memory backing those PFNs"

Link: https://lore.kernel.org/lkml/2a1592ad-bc9d-4664-fd19-f7448a37edc0@huawei.com [1]

* tag 'memblock-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  arm: extend pfn_valid to take into account freed memory map alignment
  memblock: ensure there is no overflow in memblock_overlaps_region()
  memblock: align freed memory map on pageblock boundaries with SPARSEMEM
  memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER
2021-07-04 12:23:05 -07:00
Dennis Zhou
93274f1dd6 percpu: flush tlb in pcpu_reclaim_populated()
Prior to "percpu: implement partial chunk depopulation",
pcpu_depopulate_chunk() was called only on the destruction path. This
meant the virtual address range was on its way back to vmalloc which
will handle flushing the tlbs for us.

However, with pcpu_reclaim_populated(), we are now calling
pcpu_depopulate_chunk() during the active lifecycle of a chunk.
Therefore, we need to flush the tlb as well otherwise we can end up
accessing the wrong page through an invalid tlb mapping as reported in
[1].

[1] https://lore.kernel.org/lkml/20210702191140.GA3166599@roeck-us.net/

Fixes: f183324133 ("percpu: implement partial chunk depopulation")
Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
2021-07-04 18:30:17 +00:00
Linus Torvalds
d3acb15a3a Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
 "iov_iter cleanups and fixes.

  There are followups, but this is what had sat in -next this cycle. IMO
  the macro forest in there became much thinner and easier to follow..."

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  csum_and_copy_to_pipe_iter(): leave handling of csum_state to caller
  clean up copy_mc_pipe_to_iter()
  pipe_zero(): we don't need no stinkin' kmap_atomic()...
  iov_iter: clean csum_and_copy_...() primitives up a bit
  copy_page_from_iter(): don't need kmap_atomic() for kvec/bvec cases
  copy_page_to_iter(): don't bother with kmap_atomic() for bvec/kvec cases
  iterate_xarray(): only of the first iteration we might get offset != 0
  pull handling of ->iov_offset into iterate_{iovec,bvec,xarray}
  iov_iter: make iterator callbacks use base and len instead of iovec
  iov_iter: make the amount already copied available to iterator callbacks
  iov_iter: get rid of separate bvec and xarray callbacks
  iov_iter: teach iterate_{bvec,xarray}() about possible short copies
  iterate_bvec(): expand bvec.h macro forest, massage a bit
  iov_iter: unify iterate_iovec and iterate_kvec
  iov_iter: massage iterate_iovec and iterate_kvec to logics similar to iterate_bvec
  iterate_and_advance(): get rid of magic in case when n is 0
  csum_and_copy_to_iter(): massage into form closer to csum_and_copy_from_iter()
  iov_iter: replace iov_iter_copy_from_user_atomic() with iterator-advancing variant
  [xarray] iov_iter_npages(): just use DIV_ROUND_UP()
  iov_iter_npages(): don't bother with iterate_all_kinds()
  ...
2021-07-03 11:30:04 -07:00
Linus Torvalds
71bd934101 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "190 patches.

  Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
  vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
  migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
  zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
  core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
  signals, exec, kcov, selftests, compress/decompress, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  ipc/util.c: use binary search for max_idx
  ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
  ipc: use kmalloc for msg_queue and shmid_kernel
  ipc sem: use kvmalloc for sem_undo allocation
  lib/decompressors: remove set but not used variabled 'level'
  selftests/vm/pkeys: exercise x86 XSAVE init state
  selftests/vm/pkeys: refill shadow register after implicit kernel write
  selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
  selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
  kcov: add __no_sanitize_coverage to fix noinstr for all architectures
  exec: remove checks in __register_bimfmt()
  x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
  hfsplus: report create_date to kstat.btime
  hfsplus: remove unnecessary oom message
  nilfs2: remove redundant continue statement in a while-loop
  kprobes: remove duplicated strong free_insn_page in x86 and s390
  init: print out unknown kernel parameters
  checkpatch: do not complain about positive return values starting with EPOLL
  checkpatch: improve the indented label test
  checkpatch: scripts/spdxcheck.py now requires python3
  ...
2021-07-02 12:08:10 -07:00
Linus Torvalds
e267992f9e Merge branch 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu
Pull percpu updates from Dennis Zhou:

 - percpu chunk depopulation - depopulate backing pages for chunks with
   empty pages when we exceed a global threshold without those pages.
   This lets us reclaim a portion of memory that would previously be
   lost until the full chunk would be freed (possibly never).

 - memcg accounting cleanup - previously separate chunks were managed
   for normal allocations and __GFP_ACCOUNT allocations. These are now
   consolidated which cleans up the code quite a bit.

 - a few misc clean ups for clang warnings

* 'for-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
  percpu: optimize locking in pcpu_balance_workfn()
  percpu: initialize best_upa variable
  percpu: rework memcg accounting
  mm, memcg: introduce mem_cgroup_kmem_disabled()
  mm, memcg: mark cgroup_memory_nosocket, nokmem and noswap as __ro_after_init
  percpu: make symbol 'pcpu_free_slot' static
  percpu: implement partial chunk depopulation
  percpu: use pcpu_free_slot instead of pcpu_nr_slots - 1
  percpu: factor out pcpu_check_block_hint()
  percpu: split __pcpu_balance_workfn()
  percpu: fix a comment about the chunks ordering
2021-07-01 17:17:24 -07:00
Alistair Popple
b756a3b5e7 mm: device exclusive memory access
Some devices require exclusive write access to shared virtual memory (SVM)
ranges to perform atomic operations on that memory.  This requires CPU
page tables to be updated to deny access whilst atomic operations are
occurring.

In order to do this introduce a new swap entry type
(SWP_DEVICE_EXCLUSIVE).  When a SVM range needs to be marked for exclusive
access by a device all page table mappings for the particular range are
replaced with device exclusive swap entries.  This causes any CPU access
to the page to result in a fault.

Faults are resovled by replacing the faulting entry with the original
mapping.  This results in MMU notifiers being called which a driver uses
to update access permissions such as revoking atomic access.  After
notifiers have been called the device will no longer have exclusive access
to the region.

Walking of the page tables to find the target pages is handled by
get_user_pages() rather than a direct page table walk.  A direct page
table walk similar to what migrate_vma_collect()/unmap() does could also
have been utilised.  However this resulted in more code similar in
functionality to what get_user_pages() provides as page faulting is
required to make the PTEs present and to break COW.

[dan.carpenter@oracle.com: fix signedness bug in make_device_exclusive_range()]
  Link: https://lkml.kernel.org/r/YNIz5NVnZ5GiZ3u1@mwanda

Link: https://lkml.kernel.org/r/20210616105937.23201-8-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Alistair Popple
9a5cc85c40 mm/memory.c: allow different return codes for copy_nonpresent_pte()
Currently if copy_nonpresent_pte() returns a non-zero value it is assumed
to be a swap entry which requires further processing outside the loop in
copy_pte_range() after dropping locks.  This prevents other values being
returned to signal conditions such as failure which a subsequent change
requires.

Instead make copy_nonpresent_pte() return an error code if further
processing is required and read the value for the swap entry in the main
loop under the ptl.

Link: https://lkml.kernel.org/r/20210616105937.23201-7-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Alistair Popple
6b49bf6ddb mm: rename migrate_pgmap_owner
MMU notifier ranges have a migrate_pgmap_owner field which is used by
drivers to store a pointer.  This is subsequently used by the driver
callback to filter MMU_NOTIFY_MIGRATE events.  Other notifier event types
can also benefit from this filtering, so rename the 'migrate_pgmap_owner'
field to 'owner' and create a new notifier initialisation function to
initialise this field.

Link: https://lkml.kernel.org/r/20210616105937.23201-6-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Suggested-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Alistair Popple
a98a2f0c8c mm/rmap: split migration into its own function
Migration is currently implemented as a mode of operation for
try_to_unmap_one() generally specified by passing the TTU_MIGRATION flag
or in the case of splitting a huge anonymous page TTU_SPLIT_FREEZE.

However it does not have much in common with the rest of the unmap
functionality of try_to_unmap_one() and thus splitting it into a separate
function reduces the complexity of try_to_unmap_one() making it more
readable.

Several simplifications can also be made in try_to_migrate_one() based on
the following observations:

 - All users of TTU_MIGRATION also set TTU_IGNORE_MLOCK.
 - No users of TTU_MIGRATION ever set TTU_IGNORE_HWPOISON.
 - No users of TTU_MIGRATION ever set TTU_BATCH_FLUSH.

TTU_SPLIT_FREEZE is a special case of migration used when splitting an
anonymous page.  This is most easily dealt with by calling the correct
function from unmap_page() in mm/huge_memory.c - either try_to_migrate()
for PageAnon or try_to_unmap().

Link: https://lkml.kernel.org/r/20210616105937.23201-5-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Alistair Popple
cd62734ca6 mm/rmap: split try_to_munlock from try_to_unmap
The behaviour of try_to_unmap_one() is difficult to follow because it
performs different operations based on a fairly large set of flags used in
different combinations.

TTU_MUNLOCK is one such flag.  However it is exclusively used by
try_to_munlock() which specifies no other flags.  Therefore rather than
overload try_to_unmap_one() with unrelated behaviour split this out into
it's own function and remove the flag.

Link: https://lkml.kernel.org/r/20210616105937.23201-4-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Alistair Popple
4dd845b5a3 mm/swapops: rework swap entry manipulation code
Both migration and device private pages use special swap entries that are
manipluated by a range of inline functions.  The arguments to these are
somewhat inconsistent so rework them to remove flag type arguments and to
make the arguments similar for both read and write entry creation.

Link: https://lkml.kernel.org/r/20210616105937.23201-3-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Alistair Popple
af5cdaf822 mm: remove special swap entry functions
Patch series "Add support for SVM atomics in Nouveau", v11.

Introduction
============

Some devices have features such as atomic PTE bits that can be used to
implement atomic access to system memory.  To support atomic operations to
a shared virtual memory page such a device needs access to that page which
is exclusive of the CPU.  This series introduces a mechanism to
temporarily unmap pages granting exclusive access to a device.

These changes are required to support OpenCL atomic operations in Nouveau
to shared virtual memory (SVM) regions allocated with the
CL_MEM_SVM_ATOMICS clSVMAlloc flag.  A more complete description of the
OpenCL SVM feature is available at
https://www.khronos.org/registry/OpenCL/specs/3.0-unified/html/
OpenCL_API.html#_shared_virtual_memory .

Implementation
==============

Exclusive device access is implemented by adding a new swap entry type
(SWAP_DEVICE_EXCLUSIVE) which is similar to a migration entry.  The main
difference is that on fault the original entry is immediately restored by
the fault handler instead of waiting.

Restoring the entry triggers calls to MMU notifers which allows a device
driver to revoke the atomic access permission from the GPU prior to the
CPU finalising the entry.

Patches
=======

Patches 1 & 2 refactor existing migration and device private entry
functions.

Patches 3 & 4 rework try_to_unmap_one() by splitting out unrelated
functionality into separate functions - try_to_migrate_one() and
try_to_munlock_one().

Patch 5 renames some existing code but does not introduce functionality.

Patch 6 is a small clean-up to swap entry handling in copy_pte_range().

Patch 7 contains the bulk of the implementation for device exclusive
memory.

Patch 8 contains some additions to the HMM selftests to ensure everything
works as expected.

Patch 9 is a cleanup for the Nouveau SVM implementation.

Patch 10 contains the implementation of atomic access for the Nouveau
driver.

Testing
=======

This has been tested with upstream Mesa 21.1.0 and a simple OpenCL program
which checks that GPU atomic accesses to system memory are atomic.
Without this series the test fails as there is no way of write-protecting
the page mapping which results in the device clobbering CPU writes.  For
reference the test is available at
https://ozlabs.org/~apopple/opencl_svm_atomics/

Further testing has been performed by adding support for testing exclusive
access to the hmm-tests kselftests.

This patch (of 10):

Remove multiple similar inline functions for dealing with different types
of special swap entries.

Both migration and device private swap entries use the swap offset to
store a pfn.  Instead of multiple inline functions to obtain a struct page
for each swap entry type use a common function pfn_swap_entry_to_page().
Also open-code the various entry_to_pfn() functions as this results is
shorter code that is easier to understand.

Link: https://lkml.kernel.org/r/20210616105937.23201-1-apopple@nvidia.com
Link: https://lkml.kernel.org/r/20210616105937.23201-2-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Marco Elver
ff06e45d3a kfence: unconditionally use unbound work queue
Unconditionally use unbound work queue, and not just if wq_power_efficient
is true.  Because if the system is idle, KFENCE may wait, and by being run
on the unbound work queue, we permit the scheduler to make better
scheduling decisions and not require pinning KFENCE to the same CPU upon
waking up.

Link: https://lkml.kernel.org/r/20210521111630.472579-1-elver@google.com
Fixes: 36f0b35d08 ("kfence: use power-efficient work queue to run delayed work")
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Hillf Danton <hdanton@sina.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Mel Gorman
ffd8f251f1 mm/page_alloc: move prototype for find_suitable_fallback
make W=1 generates the following warning in mmap_lock.c for allnoconfig

  mm/page_alloc.c:2670:5: warning: no previous prototype for `find_suitable_fallback' [-Wmissing-prototypes]
   int find_suitable_fallback(struct free_area *area, unsigned int order,
       ^~~~~~~~~~~~~~~~~~~~~~

find_suitable_fallback is only shared outside of page_alloc.c for
CONFIG_COMPACTION but to suppress the warning, move the protype outside of
CONFIG_COMPACTION.  It is not worth the effort at this time to find a
clever way of allowing compaction.c to share the code or avoid the use
entirely as the function is called on relatively slow paths.

Link: https://lkml.kernel.org/r/20210520084809.8576-14-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Mel Gorman
d01079f3d0 mm/mmap_lock: remove dead code for !CONFIG_TRACING configurations
make W=1 generates the following warning in mmap_lock.c for allnoconfig

  mm/mmap_lock.c:213:6: warning: no previous prototype for `__mmap_lock_do_trace_start_locking' [-Wmissing-prototypes]
   void __mmap_lock_do_trace_start_locking(struct mm_struct *mm, bool write)
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  mm/mmap_lock.c:219:6: warning: no previous prototype for `__mmap_lock_do_trace_acquire_returned' [-Wmissing-prototypes]
   void __mmap_lock_do_trace_acquire_returned(struct mm_struct *mm, bool write,
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  mm/mmap_lock.c:226:6: warning: no previous prototype for `__mmap_lock_do_trace_released' [-Wmissing-prototypes]
   void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write)

On !CONFIG_TRACING configurations, the code is dead so put it behind an
#ifdef.

[cuibixuan@huawei.com: fix warning when CONFIG_TRACING is not defined]
  Link: https://lkml.kernel.org/r/20210531033426.74031-1-cuibixuan@huawei.com

Link: https://lkml.kernel.org/r/20210520084809.8576-13-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Mel Gorman
30522175d2 mm/z3fold: add kerneldoc fields for z3fold_pool
make W=1 generates the following warning for z3fold_pool

  mm/z3fold.c:171: warning: Function parameter or member 'zpool' not described in 'z3fold_pool'
  mm/z3fold.c:171: warning: Function parameter or member 'zpool_ops' not described in 'z3fold_pool'

Commit 9a001fc19c ("z3fold: the 3-fold allocator for compressed pages")
simply did not document the fields at the time.  Add rudimentary
documentation.

Link: https://lkml.kernel.org/r/20210520084809.8576-11-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Mel Gorman
a29a750660 mm/zbud: add kerneldoc fields for zbud_pool
make W=1 generates the following warning for zbud_pool

  mm/zbud.c:105: warning: Function parameter or member 'zpool' not described in 'zbud_pool'
  mm/zbud.c:105: warning: Function parameter or member 'zpool_ops' not described in 'zbud_pool'

Commit 479305fd71 ("zpool: remove zpool_evict()") removed the
zpool_evict helper and added the associated zpool and operations structure
in struct zbud_pool but did not add documentation for the fields.  Add
rudimentary documentation.

Link: https://lkml.kernel.org/r/20210520084809.8576-10-mgorman@techsingularity.net
Fixes: 479305fd71 ("zpool: remove zpool_evict()")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:03 -07:00
Mel Gorman
5640c9ca7e mm/memory_hotplug: fix kerneldoc comment for __remove_memory
make W=1 generates the following warning for __remove_memory

  mm/memory_hotplug.c:2044: warning: expecting prototype for remove_memory(). Prototype was for __remove_memory() instead

Commit eca499ab37 ("mm/hotplug: make remove_memory() interface usable")
introduced the kerneldoc comment and function but the kerneldoc name and
function name did not match.

Link: https://lkml.kernel.org/r/20210520084809.8576-9-mgorman@techsingularity.net
Fixes: eca499ab37 ("mm/hotplug: make remove_memory() interface usable")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Mel Gorman
ba2d26660d mm/memory_hotplug: fix kerneldoc comment for __try_online_node
make W=1 generates the following warning for try_online_node

mm/memory_hotplug.c:1087: warning: expecting prototype for try_online_node(). Prototype was for __try_online_node() instead

Commit b9ff036082 ("mm/memory_hotplug.c: make add_memory_resource use
__try_online_node") renamed the function but did not update the associated
kerneldoc.  The function is static and somewhat specialised in nature so
it's not clear it warrants being a kerneldoc by moving the comment to
try_online_node.  Hence, leave the comment of the internal helper in place
but leave it out of kerneldoc and correct the function name in the
comment.

Link: https://lkml.kernel.org/r/20210520084809.8576-8-mgorman@techsingularity.net
Fixes: Commit b9ff036082 ("mm/memory_hotplug.c: make add_memory_resource use __try_online_node")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Mel Gorman
05395718b2 mm/memcontrol.c: fix kerneldoc comment for mem_cgroup_calculate_protection
make W=1 generates the following warning for mem_cgroup_calculate_protection

  mm/memcontrol.c:6468: warning: expecting prototype for mem_cgroup_protected(). Prototype was for mem_cgroup_calculate_protection() instead

Commit 45c7f7e1ef ("mm, memcg: decouple e{low,min} state mutations from
protection checks") changed the function definition but not the associated
kerneldoc comment.

Link: https://lkml.kernel.org/r/20210520084809.8576-7-mgorman@techsingularity.net
Fixes: 45c7f7e1ef ("mm, memcg: decouple e{low,min} state mutations from protection checks")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Mel Gorman
b417941f3a mm/mapping_dirty_helpers: remove double Note in kerneldoc
make W=1 generates the following warning for mm/mapping_dirty_helpers.c

mm/mapping_dirty_helpers.c:325: warning: duplicate section name 'Note'

The helper function is very specific to one driver -- vmwgfx.  While the
two notes are separate, all of it needs to be taken into account when
using the helper so make it one note.

Link: https://lkml.kernel.org/r/20210520084809.8576-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Mel Gorman
f717309003 mm/page_alloc: make should_fail_alloc_page() static
make W=1 generates the following warning for mm/page_alloc.c

  mm/page_alloc.c:3651:15: warning: no previous prototype for `should_fail_alloc_page' [-Wmissing-prototypes]
   noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
                 ^~~~~~~~~~~~~~~~~~~~~~

This function is deliberately split out for BPF to allow errors to be
injected.  The function is not used anywhere else so it is local to the
file.  Make it static which should still allow error injection to be used
similar to how block/blk-core.c:should_fail_bio() works.

Link: https://lkml.kernel.org/r/20210520084809.8576-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Mel Gorman
5da96bdd93 mm/vmalloc: include header for prototype of set_iounmap_nonlazy
make W=1 generates the following warning for mm/vmalloc.c

  mm/vmalloc.c:1599:6: warning: no previous prototype for `set_iounmap_nonlazy' [-Wmissing-prototypes]
   void set_iounmap_nonlazy(void)
        ^~~~~~~~~~~~~~~~~~~

This is an arch-generic function only used by x86.  On other arches, it's
dead code.  Include the header with the definition and make it x86-64
specific.

Link: https://lkml.kernel.org/r/20210520084809.8576-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Mel Gorman
f611fab710 mm/vmscan: remove kerneldoc-like comment from isolate_lru_pages
Patch series "Clean W=1 build warnings for mm/".

This is a janitorial only.  During development of a tool to catch build
warnings early to avoid tripping the Intel lkp-robot, I noticed that mm/
is not clean for W=1.  This is generally harmless but there is no harm in
cleaning it up.  It disrupts git blame a little but on relatively obvious
lines that are unlikely to be git blame targets.

This patch (of 13):

make W=1 generates the following warning for vmscan.c

    mm/vmscan.c:1814: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst

It is not a kerneldoc comment and isolate_lru_pages() is a static
function.  While the detailed comment is nice, it does not need to be
exposed via kernel-doc.

Link: https://lkml.kernel.org/r/20210520084809.8576-1-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20210520084809.8576-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Zhen Lei
041711ce7c mm: fix spelling mistakes
Fix some spelling mistakes in comments:
each having differents usage ==> each has a different usage
statments ==> statements
adresses ==> addresses
aggresive ==> aggressive
datas ==> data
posion ==> poison
higer ==> higher
precisly ==> precisely
wont ==> won't
We moves tha ==> We move the
endianess ==> endianness

Link: https://lkml.kernel.org/r/20210519065853.7723-2-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Hyeonggon Yoo
c4ffefd16d mm: fix typos and grammar error in comments
We moves tha -> We move that in mm/swap.c
statments -> statements in include/linux/mm.h

Link: https://lkml.kernel.org/r/20210509063444.GA24745@hyeyoo
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Miaohe Lin
3384833726 mm/zsmalloc.c: improve readability for async_free_zspage()
The class is extracted from pool->size_class[class_idx] again before
calling __free_zspage().  It looks like class will change after we fetch
the class lock.  But this is misleading as class will stay unchanged.

Link: https://lkml.kernel.org/r/20210624123930.1769093-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Miaohe Lin
ce8475b6a4 mm/zsmalloc.c: remove confusing code in obj_free()
Patch series "Cleanup for zsmalloc".

This series contains cleanups to remove confusing code in obj_free(),
combine two atomic ops and improve readability for async_free_zspage().
More details can be found in the respective changelogs.

This patch (of 2):

OBJ_ALLOCATED_TAG is only set for handle to indicate allocated object.
It's irrelevant with obj.  So remove this misleading code to improve
readability.

Link: https://lkml.kernel.org/r/20210624123930.1769093-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210624123930.1769093-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-01 11:06:02 -07:00
Miaohe Lin
46b76f2e09 mm/zswap.c: fix two bugs in zswap_writeback_entry()
In the ZSWAP_SWAPCACHE_FAIL and ZSWAP_SWAPCACHE_EXIST case, we forgot to
call zpool_unmap_handle() when zpool can't sleep. And we might sleep in
zswap_get_swap_cache_page() while zpool can't sleep. To fix all of these,
zpool_unmap_handle() should be done before zswap_get_swap_cache_page()
when zpool can't sleep.

Link: https://lkml.kernel.org/r/20210522092242.3233191-4-linmiaohe@huawei.com
Fixes: fc6697a89f ("mm/zswap: add the flag can_sleep_mapped")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Tian Tao <tiantao6@hisilicon.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:31 -07:00
Miaohe Lin
ae34af1f11 mm/zswap.c: avoid unnecessary copy-in at map time
The buf mapped via zpool_map_handle() is only used to store compressed
page buffer and there is no information to extract from it. So we could
use ZPOOL_MM_WO instead to avoid unnecessary copy-in at map time.

Link: https://lkml.kernel.org/r/20210522092242.3233191-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Tian Tao <tiantao6@hisilicon.com>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:31 -07:00
Miaohe Lin
2c1e9a2c66 mm/zswap.c: remove unused function zswap_debugfs_exit()
Patch series "Cleanup and fixup for zswap".

This series contains cleanups to remove unused function and avoid
unnecessary copy-in at map time.  Also this fixes two bugs in the function
zswap_writeback_entry().  More details can be found in the respective
changelogs.

This patch (of 3):

zswap_debugfs_exit() is unused, remove it.

Link: https://lkml.kernel.org/r/20210522092242.3233191-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210522092242.3233191-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:31 -07:00
Oscar Salvador
27cacaad16 mm,memory_hotplug: drop unneeded locking
Currently, memory-hotplug code takes zone's span_writelock and pgdat's
resize_lock when resizing the node/zone's spanned pages via
{move_pfn_range_to_zone(),remove_pfn_range_from_zone()} and when resizing
node and zone's present pages via adjust_present_page_count().

These locks are also taken during the initialization of the system at boot
time, where it protects parallel struct page initialization, but they
should not really be needed in memory-hotplug where all operations are a)
synchronized on device level and b) serialized by the mem_hotplug_lock
lock.

[akpm@linux-foundation.org: remove now-unused locals]

Link: https://lkml.kernel.org/r/20210531093958.15021-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:31 -07:00
Liam Mark
786dee8648 mm/memory_hotplug: rate limit page migration warnings
When offlining memory the system can attempt to migrate a lot of pages, if
there are problems with migration this can flood the logs.  Printing all
the data hogs the CPU and cause some RT threads to run for a long time,
which may have some bad consequences.

Rate limit the page migration warnings in order to avoid this.

Link: https://lkml.kernel.org/r/20210505140542.24935-1-georgi.djakov@linaro.org
Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:31 -07:00
David Hildenbrand
4ca9b3859d mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables
I. Background: Sparse Memory Mappings

When we manage sparse memory mappings dynamically in user space - also
sometimes involving MAP_NORESERVE - we want to dynamically populate/
discard memory inside such a sparse memory region.  Example users are
hypervisors (especially implementing memory ballooning or similar
technologies like virtio-mem) and memory allocators.  In addition, we want
to fail in a nice way (instead of generating SIGBUS) if populating does
not succeed because we are out of backend memory (which can happen easily
with file-based mappings, especially tmpfs and hugetlbfs).

While MADV_DONTNEED, MADV_REMOVE and FALLOC_FL_PUNCH_HOLE allow for
reliably discarding memory for most mapping types, there is no generic
approach to populate page tables and preallocate memory.

Although mmap() supports MAP_POPULATE, it is not applicable to the concept
of sparse memory mappings, where we want to populate/discard dynamically
and avoid expensive/problematic remappings.  In addition, we never
actually report errors during the final populate phase - it is best-effort
only.

fallocate() can be used to preallocate file-based memory and fail in a
safe way.  However, it cannot really be used for any private mappings on
anonymous files via memfd due to COW semantics.  In addition, fallocate()
does not actually populate page tables, so we still always get pagefaults
on first access - which is sometimes undesired (i.e., real-time workloads)
and requires real prefaulting of page tables, not just a preallocation of
backend storage.  There might be interesting use cases for sparse memory
regions along with mlockall(MCL_ONFAULT) which fallocate() cannot satisfy
as it does not prefault page tables.

II. On preallcoation/prefaulting from user space

Because we don't have a proper interface, what applications (like QEMU and
databases) end up doing is touching (i.e., reading+writing one byte to not
overwrite existing data) all individual pages.

However, that approach
1) Can result in wear on storage backing, because we end up reading/writing
   each page; this is especially a problem for dax/pmem.
2) Can result in mmap_sem contention when prefaulting via multiple
   threads.
3) Requires expensive signal handling, especially to catch SIGBUS in case
   of hugetlbfs/shmem/file-backed memory. For example, this is
   problematic in hypervisors like QEMU where SIGBUS handlers might already
   be used by other subsystems concurrently to e.g, handle hardware errors.
   "Simply" doing preallocation concurrently from other thread is not that
   easy.

III. On MADV_WILLNEED

Extending MADV_WILLNEED is not an option because
1. It would change the semantics: "Expect access in the near future." and
   "might be a good idea to read some pages" vs. "Definitely populate/
   preallocate all memory and definitely fail on errors.".
2. Existing users (like virtio-balloon in QEMU when deflating the balloon)
   don't want populate/prealloc semantics. They treat this rather as a hint
   to give a little performance boost without too much overhead - and don't
   expect that a lot of memory might get consumed or a lot of time
   might be spent.

IV. MADV_POPULATE_READ and MADV_POPULATE_WRITE

Let's introduce MADV_POPULATE_READ and MADV_POPULATE_WRITE, inspired by
MAP_POPULATE, with the following semantics:
1. MADV_POPULATE_READ can be used to prefault page tables just like
   manually reading each individual page. This will not break any COW
   mappings. The shared zero page might get mapped and no backend storage
   might get preallocated -- allocation might be deferred to
   write-fault time. Especially shared file mappings require an explicit
   fallocate() upfront to actually preallocate backend memory (blocks in
   the file system) in case the file might have holes.
2. If MADV_POPULATE_READ succeeds, all page tables have been populated
   (prefaulted) readable once.
3. MADV_POPULATE_WRITE can be used to preallocate backend memory and
   prefault page tables just like manually writing (or
   reading+writing) each individual page. This will break any COW
   mappings -- e.g., the shared zeropage is never populated.
4. If MADV_POPULATE_WRITE succeeds, all page tables have been populated
   (prefaulted) writable once.
5. MADV_POPULATE_READ and MADV_POPULATE_WRITE cannot be applied to special
   mappings marked with VM_PFNMAP and VM_IO. Also, proper access
   permissions (e.g., PROT_READ, PROT_WRITE) are required. If any such
   mapping is encountered, madvise() fails with -EINVAL.
6. If MADV_POPULATE_READ or MADV_POPULATE_WRITE fails, some page tables
   might have been populated.
7. MADV_POPULATE_READ and MADV_POPULATE_WRITE will return -EHWPOISON
   when encountering a HW poisoned page in the range.
8. Similar to MAP_POPULATE, MADV_POPULATE_READ and MADV_POPULATE_WRITE
   cannot protect from the OOM (Out Of Memory) handler killing the
   process.

While the use case for MADV_POPULATE_WRITE is fairly obvious (i.e.,
preallocate memory and prefault page tables for VMs), one issue is that
whenever we prefault pages writable, the pages have to be marked dirty,
because the CPU could dirty them any time.  while not a real problem for
hugetlbfs or dax/pmem, it can be a problem for shared file mappings: each
page will be marked dirty and has to be written back later when evicting.

MADV_POPULATE_READ allows for optimizing this scenario: Pre-read a whole
mapping from backend storage without marking it dirty, such that eviction
won't have to write it back.  As discussed above, shared file mappings
might require an explciit fallocate() upfront to achieve
preallcoation+prepopulation.

Although sparse memory mappings are the primary use case, this will also
be useful for other preallocate/prefault use cases where MAP_POPULATE is
not desired or the semantics of MAP_POPULATE are not sufficient: as one
example, QEMU users can trigger preallocation/prefaulting of guest RAM
after the mapping was created -- and don't want errors to be silently
suppressed.

Looking at the history, MADV_POPULATE was already proposed in 2013 [1],
however, the main motivation back than was performance improvements --
which should also still be the case.

V. Single-threaded performance comparison

I did a short experiment, prefaulting page tables on completely *empty
mappings/files* and repeated the experiment 10 times.  The results
correspond to the shortest execution time.  In general, the performance
benefit for huge pages is negligible with small mappings.

V.1: Private mappings

POPULATE_READ and POPULATE_WRITE is fastest.  Note that
Reading/POPULATE_READ will populate the shared zeropage where applicable
-- which result in short population times.

The fastest way to allocate backend storage (here: swap or huge pages) and
prefault page tables is POPULATE_WRITE.

V.2: Shared mappings

fallocate() is fastest, however, doesn't prefault page tables.
POPULATE_WRITE is faster than simple writes and read/writes.
POPULATE_READ is faster than simple reads.

Without a fd, the fastest way to allocate backend storage and prefault
page tables is POPULATE_WRITE.  With an fd, the fastest way is usually
FALLOCATE+POPULATE_READ or FALLOCATE+POPULATE_WRITE respectively; one
exception are actual files: FALLOCATE+Read is slightly faster than
FALLOCATE+POPULATE_READ.

The fastest way to allocate backend storage prefault page tables is
FALLOCATE+POPULATE_WRITE -- except when dealing with actual files; then,
FALLOCATE+POPULATE_READ is fastest and won't directly mark all pages as
dirty.

v.3: Detailed results

==================================================
2 MiB MAP_PRIVATE:
**************************************************
Anon 4 KiB     : Read                     :     0.119 ms
Anon 4 KiB     : Write                    :     0.222 ms
Anon 4 KiB     : Read/Write               :     0.380 ms
Anon 4 KiB     : POPULATE_READ            :     0.060 ms
Anon 4 KiB     : POPULATE_WRITE           :     0.158 ms
Memfd 4 KiB    : Read                     :     0.034 ms
Memfd 4 KiB    : Write                    :     0.310 ms
Memfd 4 KiB    : Read/Write               :     0.362 ms
Memfd 4 KiB    : POPULATE_READ            :     0.039 ms
Memfd 4 KiB    : POPULATE_WRITE           :     0.229 ms
Memfd 2 MiB    : Read                     :     0.030 ms
Memfd 2 MiB    : Write                    :     0.030 ms
Memfd 2 MiB    : Read/Write               :     0.030 ms
Memfd 2 MiB    : POPULATE_READ            :     0.030 ms
Memfd 2 MiB    : POPULATE_WRITE           :     0.030 ms
tmpfs          : Read                     :     0.033 ms
tmpfs          : Write                    :     0.313 ms
tmpfs          : Read/Write               :     0.406 ms
tmpfs          : POPULATE_READ            :     0.039 ms
tmpfs          : POPULATE_WRITE           :     0.285 ms
file           : Read                     :     0.033 ms
file           : Write                    :     0.351 ms
file           : Read/Write               :     0.408 ms
file           : POPULATE_READ            :     0.039 ms
file           : POPULATE_WRITE           :     0.290 ms
hugetlbfs      : Read                     :     0.030 ms
hugetlbfs      : Write                    :     0.030 ms
hugetlbfs      : Read/Write               :     0.030 ms
hugetlbfs      : POPULATE_READ            :     0.030 ms
hugetlbfs      : POPULATE_WRITE           :     0.030 ms
**************************************************
4096 MiB MAP_PRIVATE:
**************************************************
Anon 4 KiB     : Read                     :   237.940 ms
Anon 4 KiB     : Write                    :   708.409 ms
Anon 4 KiB     : Read/Write               :  1054.041 ms
Anon 4 KiB     : POPULATE_READ            :   124.310 ms
Anon 4 KiB     : POPULATE_WRITE           :   572.582 ms
Memfd 4 KiB    : Read                     :   136.928 ms
Memfd 4 KiB    : Write                    :   963.898 ms
Memfd 4 KiB    : Read/Write               :  1106.561 ms
Memfd 4 KiB    : POPULATE_READ            :    78.450 ms
Memfd 4 KiB    : POPULATE_WRITE           :   805.881 ms
Memfd 2 MiB    : Read                     :   357.116 ms
Memfd 2 MiB    : Write                    :   357.210 ms
Memfd 2 MiB    : Read/Write               :   357.606 ms
Memfd 2 MiB    : POPULATE_READ            :   356.094 ms
Memfd 2 MiB    : POPULATE_WRITE           :   356.937 ms
tmpfs          : Read                     :   137.536 ms
tmpfs          : Write                    :   954.362 ms
tmpfs          : Read/Write               :  1105.954 ms
tmpfs          : POPULATE_READ            :    80.289 ms
tmpfs          : POPULATE_WRITE           :   822.826 ms
file           : Read                     :   137.874 ms
file           : Write                    :   987.025 ms
file           : Read/Write               :  1107.439 ms
file           : POPULATE_READ            :    80.413 ms
file           : POPULATE_WRITE           :   857.622 ms
hugetlbfs      : Read                     :   355.607 ms
hugetlbfs      : Write                    :   355.729 ms
hugetlbfs      : Read/Write               :   356.127 ms
hugetlbfs      : POPULATE_READ            :   354.585 ms
hugetlbfs      : POPULATE_WRITE           :   355.138 ms
**************************************************
2 MiB MAP_SHARED:
**************************************************
Anon 4 KiB     : Read                     :     0.394 ms
Anon 4 KiB     : Write                    :     0.348 ms
Anon 4 KiB     : Read/Write               :     0.400 ms
Anon 4 KiB     : POPULATE_READ            :     0.326 ms
Anon 4 KiB     : POPULATE_WRITE           :     0.273 ms
Anon 2 MiB     : Read                     :     0.030 ms
Anon 2 MiB     : Write                    :     0.030 ms
Anon 2 MiB     : Read/Write               :     0.030 ms
Anon 2 MiB     : POPULATE_READ            :     0.030 ms
Anon 2 MiB     : POPULATE_WRITE           :     0.030 ms
Memfd 4 KiB    : Read                     :     0.412 ms
Memfd 4 KiB    : Write                    :     0.372 ms
Memfd 4 KiB    : Read/Write               :     0.419 ms
Memfd 4 KiB    : POPULATE_READ            :     0.343 ms
Memfd 4 KiB    : POPULATE_WRITE           :     0.288 ms
Memfd 4 KiB    : FALLOCATE                :     0.137 ms
Memfd 4 KiB    : FALLOCATE+Read           :     0.446 ms
Memfd 4 KiB    : FALLOCATE+Write          :     0.330 ms
Memfd 4 KiB    : FALLOCATE+Read/Write     :     0.454 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_READ  :     0.379 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_WRITE :     0.268 ms
Memfd 2 MiB    : Read                     :     0.030 ms
Memfd 2 MiB    : Write                    :     0.030 ms
Memfd 2 MiB    : Read/Write               :     0.030 ms
Memfd 2 MiB    : POPULATE_READ            :     0.030 ms
Memfd 2 MiB    : POPULATE_WRITE           :     0.030 ms
Memfd 2 MiB    : FALLOCATE                :     0.030 ms
Memfd 2 MiB    : FALLOCATE+Read           :     0.031 ms
Memfd 2 MiB    : FALLOCATE+Write          :     0.031 ms
Memfd 2 MiB    : FALLOCATE+Read/Write     :     0.031 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_READ  :     0.030 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_WRITE :     0.030 ms
tmpfs          : Read                     :     0.416 ms
tmpfs          : Write                    :     0.369 ms
tmpfs          : Read/Write               :     0.425 ms
tmpfs          : POPULATE_READ            :     0.346 ms
tmpfs          : POPULATE_WRITE           :     0.295 ms
tmpfs          : FALLOCATE                :     0.139 ms
tmpfs          : FALLOCATE+Read           :     0.447 ms
tmpfs          : FALLOCATE+Write          :     0.333 ms
tmpfs          : FALLOCATE+Read/Write     :     0.454 ms
tmpfs          : FALLOCATE+POPULATE_READ  :     0.380 ms
tmpfs          : FALLOCATE+POPULATE_WRITE :     0.272 ms
file           : Read                     :     0.191 ms
file           : Write                    :     0.511 ms
file           : Read/Write               :     0.524 ms
file           : POPULATE_READ            :     0.196 ms
file           : POPULATE_WRITE           :     0.434 ms
file           : FALLOCATE                :     0.004 ms
file           : FALLOCATE+Read           :     0.197 ms
file           : FALLOCATE+Write          :     0.554 ms
file           : FALLOCATE+Read/Write     :     0.480 ms
file           : FALLOCATE+POPULATE_READ  :     0.201 ms
file           : FALLOCATE+POPULATE_WRITE :     0.381 ms
hugetlbfs      : Read                     :     0.030 ms
hugetlbfs      : Write                    :     0.030 ms
hugetlbfs      : Read/Write               :     0.030 ms
hugetlbfs      : POPULATE_READ            :     0.030 ms
hugetlbfs      : POPULATE_WRITE           :     0.030 ms
hugetlbfs      : FALLOCATE                :     0.030 ms
hugetlbfs      : FALLOCATE+Read           :     0.031 ms
hugetlbfs      : FALLOCATE+Write          :     0.031 ms
hugetlbfs      : FALLOCATE+Read/Write     :     0.030 ms
hugetlbfs      : FALLOCATE+POPULATE_READ  :     0.030 ms
hugetlbfs      : FALLOCATE+POPULATE_WRITE :     0.030 ms
**************************************************
4096 MiB MAP_SHARED:
**************************************************
Anon 4 KiB     : Read                     :  1053.090 ms
Anon 4 KiB     : Write                    :   913.642 ms
Anon 4 KiB     : Read/Write               :  1060.350 ms
Anon 4 KiB     : POPULATE_READ            :   893.691 ms
Anon 4 KiB     : POPULATE_WRITE           :   782.885 ms
Anon 2 MiB     : Read                     :   358.553 ms
Anon 2 MiB     : Write                    :   358.419 ms
Anon 2 MiB     : Read/Write               :   357.992 ms
Anon 2 MiB     : POPULATE_READ            :   357.533 ms
Anon 2 MiB     : POPULATE_WRITE           :   357.808 ms
Memfd 4 KiB    : Read                     :  1078.144 ms
Memfd 4 KiB    : Write                    :   942.036 ms
Memfd 4 KiB    : Read/Write               :  1100.391 ms
Memfd 4 KiB    : POPULATE_READ            :   925.829 ms
Memfd 4 KiB    : POPULATE_WRITE           :   804.394 ms
Memfd 4 KiB    : FALLOCATE                :   304.632 ms
Memfd 4 KiB    : FALLOCATE+Read           :  1163.359 ms
Memfd 4 KiB    : FALLOCATE+Write          :   933.186 ms
Memfd 4 KiB    : FALLOCATE+Read/Write     :  1187.304 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_READ  :  1013.660 ms
Memfd 4 KiB    : FALLOCATE+POPULATE_WRITE :   794.560 ms
Memfd 2 MiB    : Read                     :   358.131 ms
Memfd 2 MiB    : Write                    :   358.099 ms
Memfd 2 MiB    : Read/Write               :   358.250 ms
Memfd 2 MiB    : POPULATE_READ            :   357.563 ms
Memfd 2 MiB    : POPULATE_WRITE           :   357.334 ms
Memfd 2 MiB    : FALLOCATE                :   356.735 ms
Memfd 2 MiB    : FALLOCATE+Read           :   358.152 ms
Memfd 2 MiB    : FALLOCATE+Write          :   358.331 ms
Memfd 2 MiB    : FALLOCATE+Read/Write     :   358.018 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_READ  :   357.286 ms
Memfd 2 MiB    : FALLOCATE+POPULATE_WRITE :   357.523 ms
tmpfs          : Read                     :  1087.265 ms
tmpfs          : Write                    :   950.840 ms
tmpfs          : Read/Write               :  1107.567 ms
tmpfs          : POPULATE_READ            :   922.605 ms
tmpfs          : POPULATE_WRITE           :   810.094 ms
tmpfs          : FALLOCATE                :   306.320 ms
tmpfs          : FALLOCATE+Read           :  1169.796 ms
tmpfs          : FALLOCATE+Write          :   933.730 ms
tmpfs          : FALLOCATE+Read/Write     :  1191.610 ms
tmpfs          : FALLOCATE+POPULATE_READ  :  1020.474 ms
tmpfs          : FALLOCATE+POPULATE_WRITE :   798.945 ms
file           : Read                     :   654.101 ms
file           : Write                    :  1259.142 ms
file           : Read/Write               :  1289.509 ms
file           : POPULATE_READ            :   661.642 ms
file           : POPULATE_WRITE           :  1106.816 ms
file           : FALLOCATE                :     1.864 ms
file           : FALLOCATE+Read           :   656.328 ms
file           : FALLOCATE+Write          :  1153.300 ms
file           : FALLOCATE+Read/Write     :  1180.613 ms
file           : FALLOCATE+POPULATE_READ  :   668.347 ms
file           : FALLOCATE+POPULATE_WRITE :   996.143 ms
hugetlbfs      : Read                     :   357.245 ms
hugetlbfs      : Write                    :   357.413 ms
hugetlbfs      : Read/Write               :   357.120 ms
hugetlbfs      : POPULATE_READ            :   356.321 ms
hugetlbfs      : POPULATE_WRITE           :   356.693 ms
hugetlbfs      : FALLOCATE                :   355.927 ms
hugetlbfs      : FALLOCATE+Read           :   357.074 ms
hugetlbfs      : FALLOCATE+Write          :   357.120 ms
hugetlbfs      : FALLOCATE+Read/Write     :   356.983 ms
hugetlbfs      : FALLOCATE+POPULATE_READ  :   356.413 ms
hugetlbfs      : FALLOCATE+POPULATE_WRITE :   356.266 ms
**************************************************

[1] https://lkml.org/lkml/2013/6/27/698

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/20210419135443.12822-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
David Hildenbrand
a78f1ccd37 mm: make variable names for populate_vma_page_range() consistent
Patch series "mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables", v2.

Excessive details on MADV_POPULATE_(READ|WRITE) can be found in patch #2.

This patch (of 5):

Let's make the variable names in the function declaration match the
variable names used in the definition.

Link: https://lkml.kernel.org/r/20210419135443.12822-1-david@redhat.com
Link: https://lkml.kernel.org/r/20210419135443.12822-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Kefeng Wang
63703f37aa mm: generalize ZONE_[DMA|DMA32]
ZONE_[DMA|DMA32] configs have duplicate definitions on platforms that
subscribe to them.  Instead, just make them generic options which can be
selected on applicable platforms.

Also only x86/arm64 architectures could enable both ZONE_DMA and
ZONE_DMA32 if EXPERT, add ARCH_HAS_ZONE_DMA_SET to make dma zone
configurable and visible on the two architectures.

Link: https://lkml.kernel.org/r/20210528074557.17768-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>	[RISC-V]
Acked-by: Michal Simek <michal.simek@xilinx.com>	[microblaze]
Acked-by: Michael Ellerman <mpe@ellerman.id.au>		[powerpc]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Liam Howlett
db1d9152c9 mm/nommu: unexport do_munmap()
do_munmap() does not take the mmap_write_lock().  vm_munmap() should be
used instead.

Link: https://lkml.kernel.org/r/20210604194002.648037-1-Liam.Howlett@Oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Chen Li
176056fd74 nommu: remove __GFP_HIGHMEM in vmalloc/vzalloc
mm/nommu.c:
void *__vmalloc(unsigned long size, gfp_t gfp_mask)
{
	/*
	 *  You can't specify __GFP_HIGHMEM with kmalloc() since kmalloc()
	 * returns only a logical address.
	 */
	return kmalloc(size, (gfp_mask | __GFP_COMP) & ~__GFP_HIGHMEM);
}

nommu's __vmalloc just uses kmalloc internally and elimitates
__GFP_HIGHMEM, so it makes no sense to add __GFP_HIGHMEM for nommu's
vmalloc/vzalloc.

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/875z00rnp8.wl-chenli@uniontech.com
Signed-off-by: Chen Li <chenli@uniontech.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Matthew Wilcox (Oracle)
1212e00c93 mm/thp: fix strncpy warning
Using MAX_INPUT_BUF_SZ as the maximum length of the string makes fortify
complain as it thinks the string might be longer than the buffer, and if
it is, we will end up with a "string" that is missing a NUL terminator.
It's trivial to show that 'tok' points to a NUL-terminated string which is
less than MAX_INPUT_BUF_SZ in length, so we may as well just use strcpy()
and avoid the warning.

Link: https://lkml.kernel.org/r/20210615200242.1716568-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Hugh Dickins
36af67370e mm: hwpoison_user_mappings() try_to_unmap() with TTU_SYNC
TTU_SYNC prevents an unlikely race, when try_to_unmap() returns shortly
before the page is accounted as unmapped.  It is unlikely to coincide with
hwpoisoning, but now that we have the flag, hwpoison_user_mappings() would
do well to use it.

Link: https://lkml.kernel.org/r/329c28ed-95df-9a2c-8893-b444d8a6d340@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jue Wang <juew@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Hugh Dickins
ab02c252c8 mm/thp: remap_page() is only needed on anonymous THP
THP splitting's unmap_page() only sets TTU_SPLIT_FREEZE when PageAnon, and
migration entries are only inserted when TTU_MIGRATION (unused here) or
TTU_SPLIT_FREEZE is set: so it's just a waste of time for remap_page() to
search for migration entries to remove when !PageAnon.

Link: https://lkml.kernel.org/r/f987bc44-f28e-688d-2424-b4722153ed8@google.com
Fixes: baa355fd33 ("thp: file pages support for split_huge_page()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jue Wang <juew@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
1fb08ac63b mm: rmap: make try_to_unmap() void function
Currently try_to_unmap() return bool value by checking page_mapcount(),
however this may return false positive since page_mapcount() doesn't check
all subpages of compound page.  The total_mapcount() could be used
instead, but its cost is higher since it traverses all subpages.

Actually the most callers of try_to_unmap() don't care about the return
value at all.  So just need check if page is still mapped by page_mapped()
when necessary.  And page_mapped() does bail out early when it finds
mapped subpage.

Link: https://lkml.kernel.org/r/bb27e3fe-6036-b637-5086-272befbfe3da@google.com
Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jue Wang <juew@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
e346e6688c mm: thp: skip make PMD PROT_NONE if THP migration is not supported
A quick grep shows x86_64, PowerPC (book3s), ARM64 and S390 support both
NUMA balancing and THP.  But S390 doesn't support THP migration so NUMA
balancing actually can't migrate any misplaced pages.

Skip make PMD PROT_NONE for such case otherwise CPU cycles may be wasted
by pointless NUMA hinting faults on S390.

Link: https://lkml.kernel.org/r/20210518200801.7413-8-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
662aeea753 mm: migrate: check mapcount for THP instead of refcount
The generic migration path will check refcount, so no need check refcount
here.  But the old code actually prevents from migrating shared THP
(mapped by multiple processes), so bail out early if mapcount is > 1 to
keep the behavior.

Link: https://lkml.kernel.org/r/20210518200801.7413-7-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
b0b515bfb3 mm: migrate: don't split THP for misplaced NUMA page
The old behavior didn't split THP if migration is failed due to lack of
memory on the target node.  But the THP migration does split THP, so keep
the old behavior for misplaced NUMA page migration.

Link: https://lkml.kernel.org/r/20210518200801.7413-6-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
c5fc5c3ae0 mm: migrate: account THP NUMA migration counters correctly
Now both base page and THP NUMA migration is done via
migrate_misplaced_page(), keep the counters correctly for THP.

Link: https://lkml.kernel.org/r/20210518200801.7413-5-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
c5b5a3dd2c mm: thp: refactor NUMA fault handling
When the THP NUMA fault support was added THP migration was not supported
yet.  So the ad hoc THP migration was implemented in NUMA fault handling.
Since v4.14 THP migration has been supported so it doesn't make too much
sense to still keep another THP migration implementation rather than using
the generic migration code.

This patch reworks the NUMA fault handling to use generic migration
implementation to migrate misplaced page.  There is no functional change.

After the refactor the flow of NUMA fault handling looks just like its
PTE counterpart:
  Acquire ptl
  Prepare for migration (elevate page refcount)
  Release ptl
  Isolate page from lru and elevate page refcount
  Migrate the misplaced THP

If migration fails just restore the old normal PMD.

In the old code anon_vma lock was needed to serialize THP migration
against THP split, but since then the THP code has been reworked a lot, it
seems anon_vma lock is not required anymore to avoid the race.

The page refcount elevation when holding ptl should prevent from THP
split.

Use migrate_misplaced_page() for both base page and THP NUMA hinting fault
and remove all the dead and duplicate code.

[dan.carpenter@oracle.com: fix a double unlock bug]
  Link: https://lkml.kernel.org/r/YLX8uYN01JmfLnlK@mwanda

Link: https://lkml.kernel.org/r/20210518200801.7413-4-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
f4c0d8367e mm: memory: make numa_migrate_prep() non-static
The numa_migrate_prep() will be used by huge NUMA fault as well in the
following patch, make it non-static.

Link: https://lkml.kernel.org/r/20210518200801.7413-3-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Yang Shi
5db4f15c4f mm: memory: add orig_pmd to struct vm_fault
Pach series "mm: thp: use generic THP migration for NUMA hinting fault", v3.

When the THP NUMA fault support was added THP migration was not supported
yet.  So the ad hoc THP migration was implemented in NUMA fault handling.
Since v4.14 THP migration has been supported so it doesn't make too much
sense to still keep another THP migration implementation rather than using
the generic migration code.  It is definitely a maintenance burden to keep
two THP migration implementation for different code paths and it is more
error prone.  Using the generic THP migration implementation allows us
remove the duplicate code and some hacks needed by the old ad hoc
implementation.

A quick grep shows x86_64, PowerPC (book3s), ARM64 ans S390 support both
THP and NUMA balancing.  The most of them support THP migration except for
S390.  Zi Yan tried to add THP migration support for S390 before but it
was not accepted due to the design of S390 PMD.  For the discussion,
please see: https://lkml.org/lkml/2018/4/27/953.

Per the discussion with Gerald Schaefer in v1 it is acceptible to skip
huge PMD for S390 for now.

I saw there were some hacks about gup from git history, but I didn't
figure out if they have been removed or not since I just found FOLL_NUMA
code in the current gup implementation and they seems useful.

Patch #1 ~ #2 are preparation patches.
Patch #3 is the real meat.
Patch #4 ~ #6 keep consistent counters and behaviors with before.
Patch #7 skips change huge PMD to prot_none if thp migration is not supported.

Test
----
Did some tests to measure the latency of do_huge_pmd_numa_page.  The test
VM has 80 vcpus and 64G memory.  The test would create 2 processes to
consume 128G memory together which would incur memory pressure to cause
THP splits.  And it also creates 80 processes to hog cpu, and the memory
consumer processes are bound to different nodes periodically in order to
increase NUMA faults.

The below test script is used:

echo 3 > /proc/sys/vm/drop_caches

# Run stress-ng for 24 hours
./stress-ng/stress-ng --vm 2 --vm-bytes 64G --timeout 24h &
PID=$!

./stress-ng/stress-ng --cpu $NR_CPUS --timeout 24h &

# Wait for vm stressors forked
sleep 5

PID_1=`pgrep -P $PID | awk 'NR == 1'`
PID_2=`pgrep -P $PID | awk 'NR == 2'`

JOB1=`pgrep -P $PID_1`
JOB2=`pgrep -P $PID_2`

# Bind load jobs to different nodes periodically to force generate
# cross node memory access
while [ -d "/proc/$PID" ]
do
        taskset -apc 8 $JOB1
        taskset -apc 8 $JOB2
        sleep 300
        taskset -apc 58 $JOB1
        taskset -apc 58 $JOB2
        sleep 300
done

With the above test the histogram of latency of do_huge_pmd_numa_page is
as shown below.  Since the number of do_huge_pmd_numa_page varies
drastically for each run (should be due to scheduler), so I converted the
raw number to percentage.

                             patched               base
@us[stress-ng]:
[0]                          3.57%                 0.16%
[1]                          55.68%                18.36%
[2, 4)                       10.46%                40.44%
[4, 8)                       7.26%                 17.82%
[8, 16)                      21.12%                13.41%
[16, 32)                     1.06%                 4.27%
[32, 64)                     0.56%                 4.07%
[64, 128)                    0.16%                 0.35%
[128, 256)                   < 0.1%                < 0.1%
[256, 512)                   < 0.1%                < 0.1%
[512, 1K)                    < 0.1%                < 0.1%
[1K, 2K)                     < 0.1%                < 0.1%
[2K, 4K)                     < 0.1%                < 0.1%
[4K, 8K)                     < 0.1%                < 0.1%
[8K, 16K)                    < 0.1%                < 0.1%
[16K, 32K)                   < 0.1%                < 0.1%
[32K, 64K)                   < 0.1%                < 0.1%

Per the result, patched kernel is even slightly better than the base
kernel.  I think this is because the lock contention against THP split is
less than base kernel due to the refactor.

To exclude the affect from THP split, I also did test w/o memory pressure.
No obvious regression is spotted.  The below is the test result *w/o*
memory pressure.

                           patched                  base
@us[stress-ng]:
[0]                        7.97%                   18.4%
[1]                        69.63%                  58.24%
[2, 4)                     4.18%                   2.63%
[4, 8)                     0.22%                   0.17%
[8, 16)                    1.03%                   0.92%
[16, 32)                   0.14%                   < 0.1%
[32, 64)                   < 0.1%                  < 0.1%
[64, 128)                  < 0.1%                  < 0.1%
[128, 256)                 < 0.1%                  < 0.1%
[256, 512)                 0.45%                   1.19%
[512, 1K)                  15.45%                  17.27%
[1K, 2K)                   < 0.1%                  < 0.1%
[2K, 4K)                   < 0.1%                  < 0.1%
[4K, 8K)                   < 0.1%                  < 0.1%
[8K, 16K)                  0.86%                   0.88%
[16K, 32K)                 < 0.1%                  0.15%
[32K, 64K)                 < 0.1%                  < 0.1%
[64K, 128K)                < 0.1%                  < 0.1%
[128K, 256K)               < 0.1%                  < 0.1%

The series also survived a series of tests that exercise NUMA balancing
migrations by Mel.

This patch (of 7):

Add orig_pmd to struct vm_fault so the "orig_pmd" parameter used by huge
page fault could be removed, just like its PTE counterpart does.

Link: https://lkml.kernel.org/r/20210518200801.7413-1-shy828301@gmail.com
Link: https://lkml.kernel.org/r/20210518200801.7413-2-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:30 -07:00
Collin Fijalkovich
eb6ecbed0a mm, thp: relax the VM_DENYWRITE constraint on file-backed THPs
Transparent huge pages are supported for read-only non-shmem files, but
are only used for vmas with VM_DENYWRITE.  This condition ensures that
file THPs are protected from writes while an application is running
(ETXTBSY).  Any existing file THPs are then dropped from the page cache
when a file is opened for write in do_dentry_open().  Since sys_mmap
ignores MAP_DENYWRITE, this constrains the use of file THPs to vmas
produced by execve().

Systems that make heavy use of shared libraries (e.g.  Android) are unable
to apply VM_DENYWRITE through the dynamic linker, preventing them from
benefiting from the resultant reduced contention on the TLB.

This patch reduces the constraint on file THPs allowing use with any
executable mapping from a file not opened for write (see
inode_is_open_for_write()).  It also introduces additional conditions to
ensure that files opened for write will never be backed by file THPs.

Restricting the use of THPs to executable mappings eliminates the risk
that a read-only file later opened for write would encounter significant
latencies due to page cache truncation.

The ld linker flag '-z max-page-size=(hugepage size)' can be used to
produce executables with the necessary layout.  The dynamic linker must
map these file's segments at a hugepage size aligned vma for the mapping
to be backed with THPs.

Comparison of the performance characteristics of 4KB and 2MB-backed
libraries follows; the Android dex2oat tool was used to AOT compile an
example application on a single ARM core.

4KB Pages:
==========

count              event_name            # count / runtime
598,995,035,942    cpu-cycles            # 1.800861 GHz
 81,195,620,851    raw-stall-frontend    # 244.112 M/sec
347,754,466,597    iTLB-loads            # 1.046 G/sec
  2,970,248,900    iTLB-load-misses      # 0.854122% miss rate

Total test time: 332.854998 seconds.

2MB Pages:
==========

count              event_name            # count / runtime
592,872,663,047    cpu-cycles            # 1.800358 GHz
 76,485,624,143    raw-stall-frontend    # 232.261 M/sec
350,478,413,710    iTLB-loads            # 1.064 G/sec
    803,233,322    iTLB-load-misses      # 0.229182% miss rate

Total test time: 329.826087 seconds

A check of /proc/$(pidof dex2oat64)/smaps shows THPs in use:

/apex/com.android.art/lib64/libart.so
FilePmdMapped:      4096 kB

/apex/com.android.art/lib64/libart-compiler.so
FilePmdMapped:      2048 kB

Link: https://lkml.kernel.org/r/20210406000930.3455850-1-cfijalkovich@google.com
Signed-off-by: Collin Fijalkovich <cfijalkovich@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Song Liu <song@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Muchun Song
6acfb5ba15 mm: migrate: fix missing update page_private to hugetlb_page_subpool
Since commit d6995da311 ("hugetlb: use page.private for hugetlb specific
page flags") converts page.private for hugetlb specific page flags.  We
should use hugetlb_page_subpool() to get the subpool pointer instead of
page_private().

This 'could' prevent the migration of hugetlb pages.  page_private(hpage)
is now used for hugetlb page specific flags.  At migration time, the only
flag which could be set is HPageVmemmapOptimized.  This flag will only be
set if the new vmemmap reduction feature is enabled.  In addition,
!page_mapping() implies an anonymous mapping.  So, this will prevent
migration of hugetb pages in anonymous mappings if the vmemmap reduction
feature is enabled.

In addition, that if statement checked for the rare race condition of a
page being migrated while in the process of being freed.  Since that check
is now wrong, we could leak hugetlb subpool usage counts.

The commit forgot to update it in the page migration routine.  So fix it.

[songmuchun@bytedance.com: fix compiler error when !CONFIG_HUGETLB_PAGE reported by Randy]
  Link: https://lkml.kernel.org/r/20210521022747.35736-1-songmuchun@bytedance.com

Link: https://lkml.kernel.org/r/20210520025949.1866-1-songmuchun@bytedance.com
Fixes: d6995da311 ("hugetlb: use page.private for hugetlb specific page flags")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reported-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Anshuman Khandual <anshuman.khandual@arm.com>	[arm64]
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Mike Rapoport
9092d4f7a1 memblock: update initialization of reserved pages
The struct pages representing a reserved memory region are initialized
using reserve_bootmem_range() function.  This function is called for each
reserved region just before the memory is freed from memblock to the buddy
page allocator.

The struct pages for MEMBLOCK_NOMAP regions are kept with the default
values set by the memory map initialization which makes it necessary to
have a special treatment for such pages in pfn_valid() and
pfn_valid_within().

Split out initialization of the reserved pages to a function with a
meaningful name and treat the MEMBLOCK_NOMAP regions the same way as the
reserved regions and mark struct pages for the NOMAP regions as
PageReserved.

Link: https://lkml.kernel.org/r/20210511100550.28178-3-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Ben Widawsky
269fbe72cd mm/mempolicy: use unified 'nodes' for bind/interleave/prefer policies
Current structure 'mempolicy' uses a union to store the node info for
bind/interleave/perfer policies.

	union {
		short 		 preferred_node; /* preferred */
		nodemask_t	 nodes;		/* interleave/bind */
		/* undefined for default */
	} v;

Since preferred node can also be represented by a nodemask_t with only ont
bit set, unify these policies with using one nodemask_t 'nodes', which can
remove a union, simplify the code and make it easier to support future's
new policy's node info.

Link: https://lore.kernel.org/r/20200630212517.308045-7-ben.widawsky@intel.com
Link: https://lkml.kernel.org/r/1623399825-75651-1-git-send-email-feng.tang@intel.com
Co-developed-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Yang Shi
e5947d23ed mm: mempolicy: don't have to split pmd for huge zero page
When trying to migrate pages to obey mempolicy, the huge zero page is
split by inserting base zero pfn to all PTEs, then the page table walk
fallback to PTE level and just skips zero page.  Skipping zero page for
mempolicy has been the behavior of kernel since v2.6.16 due to commit
f4598c8b36 ("[PATCH] migration: make sure there is no attempt to migrate
reserved pages.").  So it seems pointless to split huge zero page, it
could be just skipped like base zero page.

Set ACTION_CONTINUE to prevent the walk_page_range() split the pmd for
this case.

Link: https://lkml.kernel.org/r/20210609172146.3594-1-shy828301@gmail.com
Link: https://lkml.kernel.org/r/20210604203513.240709-1-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Feng Tang
9583792458 mm/mempolicy: unify the parameter sanity check for mbind and set_mempolicy
Currently the kernel_mbind() and kernel_set_mempolicy() do almost the same
operation for parameter sanity check.

Add a helper function to unify the code to reduce the redundancy, and make
it easier for changing the sanity check code in future.

[thanks to David Rientjes for suggesting using helper function instead of
macro].

[feng.tang@intel.com: add comment]
  Link: https://lkml.kernel.org/r/1622560492-1294-4-git-send-email-feng.tang@intel.com

Link: https://lkml.kernel.org/r/1622469956-82897-4-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Feng Tang
7858d7bca7 mm/mempolicy: don't handle MPOL_LOCAL like a fake MPOL_PREFERRED policy
MPOL_LOCAL policy has been setup as a real policy, but it is still handled
like a faked POL_PREFERRED policy with one internal MPOL_F_LOCAL flag bit
set, and there are many places having to judge the real 'prefer' or the
'local' policy, which are quite confusing.

In current code, there are 4 cases that MPOL_LOCAL are used:

1. user specifies 'local' policy

2. user specifies 'prefer' policy, but with empty nodemask

3. system 'default' policy is used

4. 'prefer' policy + valid 'preferred' node with MPOL_F_STATIC_NODES
   flag set, and when it is 'rebind' to a nodemask which doesn't contains
   the 'preferred' node, it will perform as 'local' policy

So make 'local' a real policy instead of a fake 'prefer' one, and kill
MPOL_F_LOCAL bit, which can greatly reduce the confusion for code reading.

For case 4, the logic of mpol_rebind_preferred() is confusing, as Michal
Hocko pointed out:

: I do believe that rebinding preferred policy is just bogus and it should
: be dropped altogether on the ground that a preference is a mere hint from
: userspace where to start the allocation.  Unless I am missing something
: cpusets will be always authoritative for the final placement.  The
: preferred node just acts as a starting point and it should be really
: preserved when cpusets changes.  Otherwise we have a very subtle behavior
: corner cases.

So dump all the tricky transformation between 'prefer' and 'local', and
just record the new nodemask of rebinding.

[feng.tang@intel.com: fix a problem in mpol_set_nodemask(), per Michal Hocko]
  Link: https://lkml.kernel.org/r/1622560492-1294-3-git-send-email-feng.tang@intel.com
[feng.tang@intel.com: refine code and comments of mpol_set_nodemask(), per Michal]
  Link: https://lkml.kernel.org/r/20210603081807.GE56979@shbuild999.sh.intel.com

Link: https://lkml.kernel.org/r/1622469956-82897-3-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Feng Tang
b26e517a05 mm/mempolicy: cleanup nodemask intersection check for oom
Patch series "mm/mempolicy: some fix and semantics cleanup", v4.

Current memory policy code has some confusing and ambiguous part about
MPOL_LOCAL policy, as it is handled as a faked MPOL_PREFERRED one, and
there are many places having to distinguish them.  Also the nodemask
intersection check needs cleanup to be more explicit for OOM use, and
handle MPOL_INTERLEAVE correctly.  This patchset cleans up these and
unifies the parameter sanity check for mbind() and set_mempolicy().

This patch (of 3):

mempolicy_nodemask_intersects seem to be a general purpose mempolicy
function.  In fact it is partially tailored for the OOM purpose
instead.  The oom proper is the only existing user so rename the
function to make that purpose explicit.

While at it drop the MPOL_INTERLEAVE as those allocations never has a
nodemask defined (see alloc_page_interleave) so this is a dead code and
a confusing one because MPOL_INTERLEAVE is a hint rather than a hard
requirement so it shouldn't be considered during the OOM.

The final code can be reduced to a check for MPOL_BIND which is the
only memory policy that is a hard requirement and thus relevant to a
constrained OOM logic.

[mhocko@suse.com: changelog edits]

Link: https://lkml.kernel.org/r/1622560492-1294-1-git-send-email-feng.tang@intel.com
Link: https://lkml.kernel.org/r/1622560492-1294-2-git-send-email-feng.tang@intel.com
Link: https://lkml.kernel.org/r/1622469956-82897-1-git-send-email-feng.tang@intel.com
Link: https://lkml.kernel.org/r/1622469956-82897-2-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Wonhyuk Yang
b55ca5264b mm/compaction: fix 'limit' in fast_isolate_freepages
Because of 'min(1, ...)', fast_isolate_freepages set 'limit' to 0 or 1.
This takes away the opportunities of find candinate pages.  So, by making
enough scans available, increases the probability of finding the
appropriate freepage.

Tested it on the thpscale and the results are as follows.

                                        5.12.0                 5.12.0
                                      valnilla                patched
Amean     fault-both-1       598.15 (   0.00%)      592.56 (   0.93%)
Amean     fault-both-3      1494.47 (   0.00%)     1514.35 (  -1.33%)
Amean     fault-both-5      2519.48 (   0.00%)     2471.76 (   1.89%)
Amean     fault-both-7      3173.85 (   0.00%)     3079.19 (   2.98%)
Amean     fault-both-12     8063.83 (   0.00%)     7858.29 (   2.55%)
Amean     fault-both-18     8781.20 (   0.00%)     7827.70 *  10.86%*
Amean     fault-both-24    12576.44 (   0.00%)    12250.20 (   2.59%)
Amean     fault-both-30    18503.27 (   0.00%)    17528.11 *   5.27%*
Amean     fault-both-32    16133.69 (   0.00%)    13874.24 *  14.00%*

                                           5.12.0         5.12.0
                                          vanilla        patched
Ops Compaction migrate scanned         6547133.00     5963901.00
Ops Compaction free scanned           32452453.00    26609101.00

                        5.12        5.12
                     vanilla     patched
Duration User          27.99       28.84
Duration System       244.08      236.76
Duration Elapsed       78.27       78.38

Link: https://lkml.kernel.org/r/20210626082443.22547-1-vvghjk1234@gmail.com
Fixes: 5a811889de ("mm, compaction: use free lists to quickly locate a migration target")
Signed-off-by: Wonhyuk Yang <vvghjk1234@gmail.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Liu Xiang
d2155fe54d mm: compaction: remove duplicate !list_empty(&sublist) check
The list_splice_tail(&sublist, freelist) also do !list_empty(&sublist)
check, so remove the duplicate call.

Link: https://lkml.kernel.org/r/20210609095409.19920-1-liu.xiang@zlingsmart.com
Signed-off-by: Liu Xiang <liu.xiang@zlingsmart.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
YueHaibing
17adb230d6 mm/compaction: use DEVICE_ATTR_WO macro
Use DEVICE_ATTR_WO helper instead of plain DEVICE_ATTR, which makes the
code a bit shorter and easier to read.

Link: https://lkml.kernel.org/r/20210523064521.32912-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Miaohe Lin
2a03085ce8 mm/zbud: don't export any zbud API
The zbud doesn't need to export any API and it is meant to be used via
zpool API since the commit 12d79d64bf ("mm/zpool: update zswap to use
zpool").  So we can remove the unneeded zbud.h and move down zpool API to
avoid any forward declaration.

[linmiaohe@huawei.com: fix unused function warnings when CONFIG_ZPOOL is disabled]
  Link: https://lkml.kernel.org/r/20210619025508.1239386-1-linmiaohe@huawei.com

Link: https://lkml.kernel.org/r/20210608114515.206992-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Miaohe Lin
f356aeacf7 mm/zbud: reuse unbuddied[0] as buddied in zbud_pool
Patch series "Cleanups for zbud", v2.

This series contains just cleanups to save some possible memory in
zbud_pool and avoid exporting any unneeded zbud API.  More details can be
found in the respective changelogs

This patch (of 2):

Since commit 9d8c5b5284 ("mm: zbud: fix condition check on allocation
size"), zbud_pool.unbuddied[0] is always unused.  We can reuse it as
buddied field to save some possible memory.

Link: https://lkml.kernel.org/r/20210608114515.206992-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210608114515.206992-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Miaohe Lin
28473d91ff mm/z3fold: use release_z3fold_page_locked() to release locked z3fold page
We should use release_z3fold_page_locked() to release z3fold page when
it's locked, although it looks harmless to use release_z3fold_page() now.

Link: https://lkml.kernel.org/r/20210619093151.1492174-7-linmiaohe@huawei.com
Fixes: dcf5aedb24 ("z3fold: stricter locking and more careful reclaim")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:29 -07:00
Miaohe Lin
dac0d1cfda mm/z3fold: fix potential memory leak in z3fold_destroy_pool()
There is a memory leak in z3fold_destroy_pool() as it forgets to
free_percpu pool->unbuddied.  Call free_percpu for pool->unbuddied to fix
this issue.

Link: https://lkml.kernel.org/r/20210619093151.1492174-6-linmiaohe@huawei.com
Fixes: d30561c56f ("z3fold: use per-cpu unbuddied lists")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Miaohe Lin
767cc6c556 mm/z3fold: remove unused function handle_to_z3fold_header()
handle_to_z3fold_header() is unused now.  So we can remove it.  As a
result, get_z3fold_header() becomes the only caller of
__get_z3fold_header() and the argument lock is always true.  Therefore we
could further fold the __get_z3fold_header() into get_z3fold_header() with
lock = true.

Link: https://lkml.kernel.org/r/20210619093151.1492174-5-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Miaohe Lin
e891f60e28 mm/z3fold: remove magic number in z3fold_create_pool()
It's meaningless to pass a magic number 2 to __alloc_percpu() as there is
a minimum alignment size of PCPU_MIN_ALLOC_SIZE (> 2) in it.  Also there
is no special alignment requirement for unbuddied.  So we could replace
this magic number with nature alignment, i.e.  __alignof__(struct
list_head), to improve readability.

Link: https://lkml.kernel.org/r/20210619093151.1492174-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Miaohe Lin
014284a081 mm/z3fold: avoid possible underflow in z3fold_alloc()
It is not enough to just make sure the z3fold header is not larger than
the page size.  When z3fold header is equal to PAGE_SIZE, we would
underflow when check alloc size against PAGE_SIZE - ZHDR_SIZE_ALIGNED -
CHUNK_SIZE in z3fold_alloc().  Make sure there has remaining spaces for
its buddy to fix this theoretical issue.

Link: https://lkml.kernel.org/r/20210619093151.1492174-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Miaohe Lin
e3c0db4fec mm/z3fold: define macro NCHUNKS as TOTAL_CHUNKS - ZHDR_CHUNKS
Patch series "Cleanup and fixup for z3fold".

This series contains cleanups to remove unused function, redefine macro to
improve readability and so on.  Also this fixes several bugs in z3fold,
such as memory leak in z3fold_destroy_pool().  More details can be found
in the respective changelogs.

This patch (of 6):

To improve code readability, we could define macro NCHUNKS as TOTAL_CHUNKS
- ZHDR_CHUNKS.  No functional change intended.

Link: https://lkml.kernel.org/r/20210619093151.1492174-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20210619093151.1492174-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
David Hildenbrand
8284045193 mm: introduce page_offline_(begin|end|freeze|thaw) to synchronize setting PageOffline()
A driver might set a page logically offline -- PageOffline() -- and turn
the page inaccessible in the hypervisor; after that, access to page
content can be fatal.  One example is virtio-mem; while unplugged memory
-- marked as PageOffline() can currently be read in the hypervisor, this
will no longer be the case in the future; for example, when having a
virtio-mem device backed by huge pages in the hypervisor.

Some special PFN walkers -- i.e., /proc/kcore -- read content of random
pages after checking PageOffline(); however, these PFN walkers can race
with drivers that set PageOffline().

Let's introduce page_offline_(begin|end|freeze|thaw) for synchronizing.

page_offline_freeze()/page_offline_thaw() allows for a subsystem to
synchronize with such drivers, achieving that a page cannot be set
PageOffline() while frozen.

page_offline_begin()/page_offline_end() is used by drivers that care about
such races when setting a page PageOffline().

For simplicity, use a rwsem for now; neither drivers nor users are
performance sensitive.

Link: https://lkml.kernel.org/r/20210526093041.8800-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Aili Yao <yaoaili@kingsoft.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Kefeng Wang
781eb2cdd2 mm/kconfig: move HOLES_IN_ZONE into mm
commit a55749639dc1 ("ia64: drop marked broken DISCONTIGMEM and
VIRTUAL_MEM_MAP") drop VIRTUAL_MEM_MAP, so there is no need HOLES_IN_ZONE
on ia64.

Also move HOLES_IN_ZONE into mm/Kconfig, select it if architecture needs
this feature.

Link: https://lkml.kernel.org/r/20210417075946.181402-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Miaohe Lin
3ebc57f403 mm: workingset: define macro WORKINGSET_SHIFT
The magic number 1 is used in several places in workingset.c.  Define a
macro WORKINGSET_SHIFT for it to improve code readability.

Link: https://lkml.kernel.org/r/20210624122307.1759342-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Yu Zhao
2d2b8d2b67 mm/vmscan.c: fix potential deadlock in reclaim_pages()
Theoretically without the protect from memalloc_noreclaim_save() and
memalloc_noreclaim_restore(), reclaim_pages() can go into the block
I/O layer recursively and deadlock.

Querying 'reclaim_pages' in our kernel crash databases didn't yield
any results. So the deadlock seems unlikely to happen. A possible
explanation is that the only user of reclaim_pages(), i.e.,
MADV_PAGEOUT, is usually called before memory pressure builds up,
e.g., on Android and Chrome OS. Under such a condition, allocations in
the block I/O layer can be fulfilled without diverting to direct
reclaim and therefore the recursion is avoided.

Link: https://lkml.kernel.org/r/20210622074642.785473-1-yuzhao@google.com
Link: https://lkml.kernel.org/r/20210614194727.2684053-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:28 -07:00
Axel Rasmussen
7d64ae3ab6 userfaultfd/shmem: modify shmem_mfill_atomic_pte to use install_pte()
In a previous commit, we added the mfill_atomic_install_pte() helper.
This helper does the job of setting up PTEs for an existing page, to map
it into a given VMA.  It deals with both the anon and shmem cases, as well
as the shared and private cases.

In other words, shmem_mfill_atomic_pte() duplicates a case it already
handles.  So, expose it, and let shmem_mfill_atomic_pte() use it directly,
to reduce code duplication.

This requires that we refactor shmem_mfill_atomic_pte() a bit:

Instead of doing accounting (shmem_recalc_inode() et al) part-way through
the PTE setup, do it afterward.  This frees up mfill_atomic_install_pte()
from having to care about this accounting, and means we don't need to e.g.
shmem_uncharge() in the error path.

A side effect is this switches shmem_mfill_atomic_pte() to use
lru_cache_add_inactive_or_unevictable() instead of just lru_cache_add().
This wrapper does some extra accounting in an exceptional case, if
appropriate, so it's actually the more correct thing to use.

Link: https://lkml.kernel.org/r/20210503180737.2487560-7-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Axel Rasmussen
153132571f userfaultfd/shmem: support UFFDIO_CONTINUE for shmem
With this change, userspace can resolve a minor fault within a
shmem-backed area with a UFFDIO_CONTINUE ioctl.  The semantics for this
match those for hugetlbfs - we look up the existing page in the page
cache, and install a PTE for it.

This commit introduces a new helper: mfill_atomic_install_pte.

Why handle UFFDIO_CONTINUE for shmem in mm/userfaultfd.c, instead of in
shmem.c?  The existing userfault implementation only relies on shmem.c for
VM_SHARED VMAs.  However, minor fault handling / CONTINUE work just fine
for !VM_SHARED VMAs as well.  We'd prefer to handle CONTINUE for shmem in
one place, regardless of shared/private (to reduce code duplication).

Why add a new mfill_atomic_install_pte helper?  A problem we have with
continue is that shmem_mfill_atomic_pte() and mcopy_atomic_pte() are
*close* to what we want, but not exactly.  We do want to setup the PTEs in
a CONTINUE operation, but we don't want to e.g.  allocate a new page,
charge it (e.g.  to the shmem inode), manipulate various flags, etc.  Also
we have the problem stated above: shmem_mfill_atomic_pte() and
mcopy_atomic_pte() both handle one-half of the problem (shared / private)
continue cares about.  So, introduce mcontinue_atomic_pte(), to handle all
of the shmem continue cases.  Introduce the helper so it doesn't duplicate
code with mcopy_atomic_pte().

In a future commit, shmem_mfill_atomic_pte() will also be modified to use
this new helper.  However, since this is a bigger refactor, it seems most
clear to do it as a separate change.

Link: https://lkml.kernel.org/r/20210503180737.2487560-5-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Axel Rasmussen
c949b097ef userfaultfd/shmem: support minor fault registration for shmem
This patch allows shmem-backed VMAs to be registered for minor faults.
Minor faults are appropriately relayed to userspace in the fault path, for
VMAs with the relevant flag.

This commit doesn't hook up the UFFDIO_CONTINUE ioctl for shmem-backed
minor faults, though, so userspace doesn't yet have a way to resolve such
faults.

Because of this, we also don't yet advertise this as a supported feature.
That will be done in a separate commit when the feature is fully
implemented.

Link: https://lkml.kernel.org/r/20210503180737.2487560-4-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Axel Rasmussen
3460f6e5c1 userfaultfd/shmem: combine shmem_{mcopy_atomic,mfill_zeropage}_pte
Patch series "userfaultfd: add minor fault handling for shmem", v6.

Overview
========

See the series which added minor faults for hugetlbfs [3] for a detailed
overview of minor fault handling in general.  This series adds the same
support for shmem-backed areas.

This series is structured as follows:

- Commits 1 and 2 are cleanups.
- Commits 3 and 4 implement the new feature (minor fault handling for shmem).
- Commit 5 advertises that the feature is now available since at this point it's
  fully implemented.
- Commit 6 is a final cleanup, modifying an existing code path to re-use a new
  helper we've introduced.
- Commits 7, 8, 9, 10 update the userfaultfd selftest to exercise the feature.

Use Case
========

In some cases it is useful to have VM memory backed by tmpfs instead of
hugetlbfs.  So, this feature will be used to support the same VM live
migration use case described in my original series.

Additionally, Android folks (Lokesh Gidra <lokeshgidra@google.com>) hope
to optimize the Android Runtime garbage collector using this feature:

"The plan is to use userfaultfd for concurrently compacting the heap.
With this feature, the heap can be shared-mapped at another location where
the GC-thread(s) could continue the compaction operation without the need
to invoke userfault ioctl(UFFDIO_COPY) each time.  OTOH, if and when Java
threads get faults on the heap, UFFDIO_CONTINUE can be used to resume
execution.  Furthermore, this feature enables updating references in the
'non-moving' portion of the heap efficiently.  Without this feature,
uneccessary page copying (ioctl(UFFDIO_COPY)) would be required."

[1] https://lore.kernel.org/patchwork/cover/1388144/
[2] https://lore.kernel.org/patchwork/patch/1408161/
[3] https://lore.kernel.org/linux-fsdevel/20210301222728.176417-1-axelrasmussen@google.com/T/#t

This patch (of 9):

Previously, we did a dance where we had one calling path in userfaultfd.c
(mfill_atomic_pte), but then we split it into two in shmem_fs.h
(shmem_{mcopy_atomic,mfill_zeropage}_pte), and then rejoined into a single
shared function in shmem.c (shmem_mfill_atomic_pte).

This is all a bit overly complex.  Just call the single combined shmem
function directly, allowing us to clean up various branches, boilerplate,
etc.

While we're touching this function, two other small cleanup changes:
- offset is equivalent to pgoff, so we can get rid of offset entirely.
- Split two VM_BUG_ON cases into two statements. This means the line
  number reported when the BUG is hit specifies exactly which condition
  was true.

Link: https://lkml.kernel.org/r/20210503180737.2487560-1-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20210503180737.2487560-3-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Peter Xu
8f34f1eac3 mm/userfaultfd: fix uffd-wp special cases for fork()
We tried to do something similar in b569a17607 ("userfaultfd: wp: drop
_PAGE_UFFD_WP properly when fork") previously, but it's not doing it all
right..  A few fixes around the code path:

1. We were referencing VM_UFFD_WP vm_flags on the _old_ vma rather
   than the new vma.  That's overlooked in b569a17607, so it won't work
   as expected.  Thanks to the recent rework on fork code
   (7a4830c380), we can easily get the new vma now, so switch the
   checks to that.

2. Dropping the uffd-wp bit in copy_huge_pmd() could be wrong if the
   huge pmd is a migration huge pmd.  When it happens, instead of using
   pmd_uffd_wp(), we should use pmd_swp_uffd_wp().  The fix is simply to
   handle them separately.

3. Forget to carry over uffd-wp bit for a write migration huge pmd
   entry.  This also happens in copy_huge_pmd(), where we converted a
   write huge migration entry into a read one.

4. In copy_nonpresent_pte(), drop uffd-wp if necessary for swap ptes.

5. In copy_present_page() when COW is enforced when fork(), we also
   need to pass over the uffd-wp bit if VM_UFFD_WP is armed on the new
   vma, and when the pte to be copied has uffd-wp bit set.

Remove the comment in copy_present_pte() about this.  It won't help a huge
lot to only comment there, but comment everywhere would be an overkill.
Let's assume the commit messages would help.

[peterx@redhat.com: fix a few thp pmd missing uffd-wp bit]
  Link: https://lkml.kernel.org/r/20210428225030.9708-4-peterx@redhat.com

Link: https://lkml.kernel.org/r/20210428225030.9708-3-peterx@redhat.com
Fixes: b569a17607 ("userfaultfd: wp: drop _PAGE_UFFD_WP properly when fork")
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Peter Xu
5fc7a5f6fd mm/thp: simplify copying of huge zero page pmd when fork
Patch series "mm/uffd: Misc fix for uffd-wp and one more test".

This series tries to fix some corner case bugs for uffd-wp on either thp
or fork().  Then it introduced a new test with pagemap/pageout.

Patch layout:

Patch 1:    cleanup for THP, it'll slightly simplify the follow up patches
Patch 2-4:  misc fixes for uffd-wp here and there; please refer to each patch
Patch 5:    add pagemap support for uffd-wp
Patch 6:    add pagemap/pageout test for uffd-wp

The last test introduced can also verify some of the fixes in previous
patches, as the test will fail without the fixes.  However it's not easy
to verify all the changes in patch 2-4, but hopefully they can still be
properly reviewed.

Note that if considering the ongoing uffd-wp shmem & hugetlbfs work, patch
5 will be incomplete as it's missing e.g.  hugetlbfs part or the special
swap pte detection.  However that's not needed in this series, and since
that series is still during review, this series does not depend on that
one (the last test only runs with anonymous memory, not file-backed).  So
this series can be merged even before that series.

This patch (of 6):

Huge zero page is handled in a special path in copy_huge_pmd(), however it
should share most codes with a normal thp page.  Trying to share more code
with it by removing the special path.  The only leftover so far is the
huge zero page refcounting (mm_get_huge_zero_page()), because that's
separately done with a global counter.

This prepares for a future patch to modify the huge pmd to be installed,
so that we don't need to duplicate it explicitly into huge zero page case
too.

Link: https://lkml.kernel.org/r/20210428225030.9708-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20210428225030.9708-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mike Kravetz <mike.kravetz@oracle.com>, peterx@redhat.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Brian Geffon <bgeffon@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Upton <oupton@google.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Wang Qing <wangqing@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Naoya Horiguchi
510d25c92e mm/hwpoison: disable pcp for page_handle_poison()
Recent changes by patch "mm/page_alloc: allow high-order pages to be
stored on the per-cpu lists" makes kernels determine whether to use pcp by
pcp_allowed_order(), which breaks soft-offline for hugetlb pages.

Soft-offline dissolves a migration source page, then removes it from buddy
free list, so it's assumed that any subpage of the soft-offlined hugepage
are recognized as a buddy page just after returning from
dissolve_free_huge_page().  pcp_allowed_order() returns true for hugetlb,
so this assumption is no longer true.

So disable pcp during dissolve_free_huge_page() and take_page_off_buddy()
to prevent soft-offlined hugepages from linking to pcp lists.
Soft-offline should not be common events so the impact on performance
should be minimal.  And I think that the optimization of Mel's patch could
benefit to hugetlb so zone_pcp_disable() is called only in hwpoison
context.

Link: https://lkml.kernel.org/r/20210617092626.291006-1-nao.horiguchi@gmail.com
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Mike Kravetz
7118fc2906 hugetlb: address ref count racing in prep_compound_gigantic_page
In [1], Jann Horn points out a possible race between
prep_compound_gigantic_page and __page_cache_add_speculative.  The root
cause of the possible race is prep_compound_gigantic_page uncondittionally
setting the ref count of pages to zero.  It does this because
prep_compound_gigantic_page is handed a 'group' of pages from an allocator
and needs to convert that group of pages to a compound page.  The ref
count of each page in this 'group' is one as set by the allocator.
However, the ref count of compound page tail pages must be zero.

The potential race comes about when ref counted pages are returned from
the allocator.  When this happens, other mm code could also take a
reference on the page.  __page_cache_add_speculative is one such example.
Therefore, prep_compound_gigantic_page can not just set the ref count of
pages to zero as it does today.  Doing so would lose the reference taken
by any other code.  This would lead to BUGs in code checking ref counts
and could possibly even lead to memory corruption.

There are two possible ways to address this issue.

1) Make all allocators of gigantic groups of pages be able to return a
   properly constructed compound page.

2) Make prep_compound_gigantic_page be more careful when constructing a
   compound page.

This patch takes approach 2.

In prep_compound_gigantic_page, use cmpxchg to only set ref count to zero
if it is one.  If the cmpxchg fails, call synchronize_rcu() in the hope
that the extra ref count will be driopped during a rcu grace period.  This
is not a performance critical code path and the wait should be
accceptable.  If the ref count is still inflated after the grace period,
then undo any modifications made and return an error.

Currently prep_compound_gigantic_page is type void and does not return
errors.  Modify the two callers to check for and handle error returns.  On
error, the caller must free the 'group' of pages as they can not be used
to form a gigantic page.  After freeing pages, the runtime caller
(alloc_fresh_huge_page) will retry the allocation once.  Boot time
allocations can not be retried.

The routine prep_compound_page also unconditionally sets the ref count of
compound page tail pages to zero.  However, in this case the buddy
allocator is constructing a compound page from freshly allocated pages.
The ref count on those freshly allocated pages is already zero, so the
set_page_count(p, 0) is unnecessary and could lead to confusion.  Just
remove it.

[1] https://lore.kernel.org/linux-mm/CAG48ez23q0Jy9cuVnwAe7t_fdhMk2S7N5Hdi-GLcCeq5bsfLxw@mail.gmail.com/

Link: https://lkml.kernel.org/r/20210622021423.154662-3-mike.kravetz@oracle.com
Fixes: 58a84aa927 ("thp: set compound tail page _count to zero")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Youquan Song <youquan.song@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:27 -07:00
Mike Kravetz
48b8d744ea hugetlb: remove prep_compound_huge_page cleanup
Patch series "Fix prep_compound_gigantic_page ref count adjustment".

These patches address the possible race between
prep_compound_gigantic_page and __page_cache_add_speculative as described
by Jann Horn in [1].

The first patch simply removes the unnecessary/obsolete helper routine
prep_compound_huge_page to make the actual fix a little simpler.

The second patch is the actual fix and has a detailed explanation in the
commit message.

This potential issue has existed for almost 10 years and I am unaware of
anyone actually hitting the race.  I did not cc stable, but would be happy
to squash the patches and send to stable if anyone thinks that is a good
idea.

[1] https://lore.kernel.org/linux-mm/CAG48ez23q0Jy9cuVnwAe7t_fdhMk2S7N5Hdi-GLcCeq5bsfLxw@mail.gmail.com/

This patch (of 2):

I could not think of a reliable way to recreate the issue for testing.
Rather, I 'simulated errors' to exercise all the error paths.

The routine prep_compound_huge_page is a simple wrapper to call either
prep_compound_gigantic_page or prep_compound_page.  However, it is only
called from gather_bootmem_prealloc which only processes gigantic pages.
Eliminate the routine and call prep_compound_gigantic_page directly.

Link: https://lkml.kernel.org/r/20210622021423.154662-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20210622021423.154662-2-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Youquan Song <youquan.song@intel.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Muchun Song
e6d41f12df mm: hugetlb: introduce CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON
When using HUGETLB_PAGE_FREE_VMEMMAP, the freeing unused vmemmap pages
associated with each HugeTLB page is default off.  Now the vmemmap is PMD
mapped.  So there is no side effect when this feature is enabled with no
HugeTLB pages in the system.  Someone may want to enable this feature in
the compiler time instead of using boot command line.  So add a config to
make it default on when someone do not want to enable it via command line.

Link: https://lkml.kernel.org/r/20210616094915.34432-4-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Muchun Song
2d7a21715f mm: sparsemem: use huge PMD mapping for vmemmap pages
The preparation of splitting huge PMD mapping of vmemmap pages is ready,
so switch the mapping from PTE to PMD.

Link: https://lkml.kernel.org/r/20210616094915.34432-3-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Muchun Song
3bc2b6a725 mm: sparsemem: split the huge PMD mapping of vmemmap pages
Patch series "Split huge PMD mapping of vmemmap pages", v4.

In order to reduce the difficulty of code review in series[1].  We disable
huge PMD mapping of vmemmap pages when that feature is enabled.  In this
series, we do not disable huge PMD mapping of vmemmap pages anymore.  We
will split huge PMD mapping when needed.  When HugeTLB pages are freed
from the pool we do not attempt coalasce and move back to a PMD mapping
because it is much more complex.

[1] https://lore.kernel.org/linux-doc/20210510030027.56044-1-songmuchun@bytedance.com/

This patch (of 3):

In [1], PMD mappings of vmemmap pages were disabled if the the feature
hugetlb_free_vmemmap was enabled.  This was done to simplify the initial
implementation of vmmemap freeing for hugetlb pages.  Now, remove this
simplification by allowing PMD mapping and switching to PTE mappings as
needed for allocated hugetlb pages.

When a hugetlb page is allocated, the vmemmap page tables are walked to
free vmemmap pages.  During this walk, split huge PMD mappings to PTE
mappings as required.  In the unlikely case PTE pages can not be
allocated, return error(ENOMEM) and do not optimize vmemmap of the hugetlb
page.

When HugeTLB pages are freed from the pool, we do not attempt to
coalesce and move back to a PMD mapping because it is much more complex.

[1] https://lkml.kernel.org/r/20210510030027.56044-8-songmuchun@bytedance.com

Link: https://lkml.kernel.org/r/20210616094915.34432-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20210616094915.34432-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Mina Almasry
8cc5fcbb5b mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY
On UFFDIO_COPY, if we fail to copy the page contents while holding the
hugetlb_fault_mutex, we will drop the mutex and return to the caller after
allocating a page that consumed a reservation.  In this case there may be
a fault that double consumes the reservation.  To handle this, we free the
allocated page, fix the reservations, and allocate a temporary hugetlb
page and return that to the caller.  When the caller does the copy outside
of the lock, we again check the cache, and allocate a page consuming the
reservation, and copy over the contents.

Test:
Hacked the code locally such that resv_huge_pages underflows produce
a warning and the copy_huge_page_from_user() always fails, then:

./tools/testing/selftests/vm/userfaultfd hugetlb_shared 10
        2 /tmp/kokonut_test/huge/userfaultfd_test && echo test success
./tools/testing/selftests/vm/userfaultfd hugetlb 10
	2 /tmp/kokonut_test/huge/userfaultfd_test && echo test success

Both tests succeed and produce no warnings. After the
test runs number of free/resv hugepages is correct.

[yuehaibing@huawei.com: remove set but not used variable 'vm_alloc_shared']
  Link: https://lkml.kernel.org/r/20210601141610.28332-1-yuehaibing@huawei.com
[almasrymina@google.com: fix allocation error check and copy func name]
  Link: https://lkml.kernel.org/r/20210605010626.1459873-1-almasrymina@google.com

Link: https://lkml.kernel.org/r/20210528005029.88088-1-almasrymina@google.com
Signed-off-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Christophe Leroy
3382bbee04 mm/vmalloc: enable mapping of huge pages at pte level in vmalloc
On some architectures like powerpc, there are huge pages that are mapped
at pte level.

Enable it in vmalloc.

For that, architectures can provide arch_vmap_pte_supported_shift() that
returns the shift for pages to map at pte level.

Link: https://lkml.kernel.org/r/2c717e3b1fba1894d890feb7669f83025bfa314d.1620795204.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Christophe Leroy
f7ee1f13d6 mm/vmalloc: enable mapping of huge pages at pte level in vmap
On some architectures like powerpc, there are huge pages that are mapped
at pte level.

Enable it in vmap.

For that, architectures can provide arch_vmap_pte_range_map_size() that
returns the size of pages to map at pte level.

Link: https://lkml.kernel.org/r/fb3ccc73377832ac6708181ec419128a2f98ce36.1620795204.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Christophe Leroy
79c1c594f4 mm/hugetlb: change parameters of arch_make_huge_pte()
Patch series "Subject: [PATCH v2 0/5] Implement huge VMAP and VMALLOC on powerpc 8xx", v2.

This series implements huge VMAP and VMALLOC on powerpc 8xx.

Powerpc 8xx has 4 page sizes:
- 4k
- 16k
- 512k
- 8M

At the time being, vmalloc and vmap only support huge pages which are
leaf at PMD level.

Here the PMD level is 4M, it doesn't correspond to any supported
page size.

For now, implement use of 16k and 512k pages which is done
at PTE level.

Support of 8M pages will be implemented later, it requires use of
hugepd tables.

To allow this, the architecture provides two functions:
- arch_vmap_pte_range_map_size() which tells vmap_pte_range() what
page size to use. A stub returning PAGE_SIZE is provided when the
architecture doesn't provide this function.
- arch_vmap_pte_supported_shift() which tells __vmalloc_node_range()
what page shift to use for a given area size. A stub returning
PAGE_SHIFT is provided when the architecture doesn't provide this
function.

This patch (of 5):

At the time being, arch_make_huge_pte() has the following prototype:

  pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
			   struct page *page, int writable);

vma is used to get the pages shift or size.
vma is also used on Sparc to get vm_flags.
page is not used.
writable is not used.

In order to use this function without a vma, replace vma by shift and
flags.  Also remove the used parameters.

Link: https://lkml.kernel.org/r/cover.1620795204.git.christophe.leroy@csgroup.eu
Link: https://lkml.kernel.org/r/f4633ac6a7da2f22f31a04a89e0a7026bb78b15b.1620795204.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Uladzislau Rezki <uladzislau.rezki@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Miaohe Lin
babbbdd08a mm/huge_memory.c: don't discard hugepage if other processes are mapping it
If other processes are mapping any other subpages of the hugepage, i.e.
in pte-mapped thp case, page_mapcount() will return 1 incorrectly.  Then
we would discard the page while other processes are still mapping it.  Fix
it by using total_mapcount() which can tell whether other processes are
still mapping it.

Link: https://lkml.kernel.org/r/20210511134857.1581273-6-linmiaohe@huawei.com
Fixes: b8d3c4c300 ("mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called")
Reviewed-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Miaohe Lin
9132a468aa mm/huge_memory.c: remove unnecessary tlb_remove_page_size() for huge zero pmd
Commit aa88b68c3b ("thp: keep huge zero page pinned until tlb flush")
introduced tlb_remove_page() for huge zero page to keep it pinned until
flush is complete and prevents the page from being split under us.  But
huge zero page is kept pinned until all relevant mm_users reach zero since
the commit 6fcb52a56f ("thp: reduce usage of huge zero page's atomic
counter").  So tlb_remove_page_size() for huge zero pmd is unnecessary
now.

Link: https://lkml.kernel.org/r/20210511134857.1581273-5-linmiaohe@huawei.com
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Miaohe Lin
e6be37b2e7 mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled()
Since commit 99cb0dbd47 ("mm,thp: add read-only THP support for
(non-shmem) FS"), read-only THP file mapping is supported.  But it forgot
to add checking for it in transparent_hugepage_enabled().  To fix it, we
add checking for read-only THP file mapping and also introduce helper
transhuge_vma_enabled() to check whether thp is enabled for specified vma
to reduce duplicated code.  We rename transparent_hugepage_enabled to
transparent_hugepage_active to make the code easier to follow as suggested
by David Hildenbrand.

[linmiaohe@huawei.com: define transhuge_vma_enabled next to transhuge_vma_suitable]
  Link: https://lkml.kernel.org/r/20210514093007.4117906-1-linmiaohe@huawei.com

Link: https://lkml.kernel.org/r/20210511134857.1581273-4-linmiaohe@huawei.com
Fixes: 99cb0dbd47 ("mm,thp: add read-only THP support for (non-shmem) FS")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Miaohe Lin
dfe5c51c60 mm/huge_memory.c: use page->deferred_list
Now that we can represent the location of ->deferred_list instead of
->mapping + ->index, make use of it to improve readability.

Link: https://lkml.kernel.org/r/20210511134857.1581273-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Shixin Liu
b593b90dc9 mm/debug_vm_pgtable: remove redundant pfn_{pmd/pte}() and fix one comment mistake
Remove redundant pfn_{pmd/pte}() in {pmd/pte}_advanced_tests() and adjust
pfn_pud() in pud_advanced_tests() to make it similar with other two
functions.

In addition, the branch condition should be CONFIG_TRANSPARENT_HUGEPAGE
instead of CONFIG_ARCH_HAS_PTE_DEVMAP.

Link: https://lkml.kernel.org/r/20210419071820.750217-2-liushixin2@huawei.com
Signed-off-by: Shixin Liu <liushixin2@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:26 -07:00
Shixin Liu
5fe77be6bf mm/debug_vm_pgtable: move {pmd/pud}_huge_tests out of CONFIG_TRANSPARENT_HUGEPAGE
The functions {pmd/pud}_set_huge and {pmd/pud}_clear_huge are not
dependent on THP.  Hence move {pmd/pud}_huge_tests out of
CONFIG_TRANSPARENT_HUGEPAGE.

Link: https://lkml.kernel.org/r/20210419071820.750217-1-liushixin2@huawei.com
Signed-off-by: Shixin Liu <liushixin2@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
774905878f mm: hugetlb: introduce nr_free_vmemmap_pages in the struct hstate
All the infrastructure is ready, so we introduce nr_free_vmemmap_pages
field in the hstate to indicate how many vmemmap pages associated with a
HugeTLB page that can be freed to buddy allocator.  And initialize it in
the hugetlb_vmemmap_init().  This patch is actual enablement of the
feature.

There are only (RESERVE_VMEMMAP_SIZE / sizeof(struct page)) struct page
structs that can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so add a
BUILD_BUG_ON to catch invalid usage of the tail struct page.

Link: https://lkml.kernel.org/r/20210510030027.56044-10-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
4bab4964a5 mm: memory_hotplug: disable memmap_on_memory when hugetlb_free_vmemmap enabled
The parameter of memory_hotplug.memmap_on_memory is not compatible with
hugetlb_free_vmemmap.  So disable it when hugetlb_free_vmemmap is enabled.

[akpm@linux-foundation.org: remove unneeded include, per Oscar]

Link: https://lkml.kernel.org/r/20210510030027.56044-9-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
e9fdff87e8 mm: hugetlb: add a kernel parameter hugetlb_free_vmemmap
Add a kernel parameter hugetlb_free_vmemmap to enable the feature of
freeing unused vmemmap pages associated with each hugetlb page on boot.

We disable PMD mapping of vmemmap pages for x86-64 arch when this feature
is enabled.  Because vmemmap_remap_free() depends on vmemmap being base
page mapped.

Link: https://lkml.kernel.org/r/20210510030027.56044-8-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
ad2fa3717b mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page
When we free a HugeTLB page to the buddy allocator, we need to allocate
the vmemmap pages associated with it.  However, we may not be able to
allocate the vmemmap pages when the system is under memory pressure.  In
this case, we just refuse to free the HugeTLB page.  This changes behavior
in some corner cases as listed below:

 1) Failing to free a huge page triggered by the user (decrease nr_pages).

    User needs to try again later.

 2) Failing to free a surplus huge page when freed by the application.

    Try again later when freeing a huge page next time.

 3) Failing to dissolve a free huge page on ZONE_MOVABLE via
    offline_pages().

    This can happen when we have plenty of ZONE_MOVABLE memory, but
    not enough kernel memory to allocate vmemmmap pages.  We may even
    be able to migrate huge page contents, but will not be able to
    dissolve the source huge page.  This will prevent an offline
    operation and is unfortunate as memory offlining is expected to
    succeed on movable zones.  Users that depend on memory hotplug
    to succeed for movable zones should carefully consider whether the
    memory savings gained from this feature are worth the risk of
    possibly not being able to offline memory in certain situations.

 4) Failing to dissolve a huge page on CMA/ZONE_MOVABLE via
    alloc_contig_range() - once we have that handling in place. Mainly
    affects CMA and virtio-mem.

    Similar to 3). virito-mem will handle migration errors gracefully.
    CMA might be able to fallback on other free areas within the CMA
    region.

Vmemmap pages are allocated from the page freeing context.  In order for
those allocations to be not disruptive (e.g.  trigger oom killer)
__GFP_NORETRY is used.  hugetlb_lock is dropped for the allocation because
a non sleeping allocation would be too fragile and it could fail too
easily under memory pressure.  GFP_ATOMIC or other modes to access memory
reserves is not used because we want to prevent consuming reserves under
heavy hugetlb freeing.

[mike.kravetz@oracle.com: fix dissolve_free_huge_page use of tail/head page]
  Link: https://lkml.kernel.org/r/20210527231225.226987-1-mike.kravetz@oracle.com
[willy@infradead.org: fix alloc_vmemmap_page_list documentation warning]
  Link: https://lkml.kernel.org/r/20210615200242.1716568-6-willy@infradead.org

Link: https://lkml.kernel.org/r/20210510030027.56044-7-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
b65d4adbc0 mm: hugetlb: defer freeing of HugeTLB pages
In the subsequent patch, we should allocate the vmemmap pages when freeing
a HugeTLB page.  But update_and_free_page() can be called under any
context, so we cannot use GFP_KERNEL to allocate vmemmap pages.  However,
we can defer the actual freeing in a kworker to prevent from using
GFP_ATOMIC to allocate the vmemmap pages.

The __update_and_free_page() is where the call to allocate vmemmmap pages
will be inserted.

Link: https://lkml.kernel.org/r/20210510030027.56044-6-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
f41f2ed43c mm: hugetlb: free the vmemmap pages associated with each HugeTLB page
Every HugeTLB has more than one struct page structure.  We __know__ that
we only use the first 4 (__NR_USED_SUBPAGE) struct page structures to
store metadata associated with each HugeTLB.

There are a lot of struct page structures associated with each HugeTLB
page.  For tail pages, the value of compound_head is the same.  So we can
reuse first page of tail page structures.  We map the virtual addresses of
the remaining pages of tail page structures to the first tail page struct,
and then free these page frames.  Therefore, we need to reserve two pages
as vmemmap areas.

When we allocate a HugeTLB page from the buddy, we can free some vmemmap
pages associated with each HugeTLB page.  It is more appropriate to do it
in the prep_new_huge_page().

The free_vmemmap_pages_per_hpage(), which indicates how many vmemmap pages
associated with a HugeTLB page can be freed, returns zero for now, which
means the feature is disabled.  We will enable it once all the
infrastructure is there.

[willy@infradead.org: fix documentation warning]
  Link: https://lkml.kernel.org/r/20210615200242.1716568-5-willy@infradead.org

Link: https://lkml.kernel.org/r/20210510030027.56044-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Muchun Song
426e5c429d mm: memory_hotplug: factor out bootmem core functions to bootmem_info.c
Patch series "Free some vmemmap pages of HugeTLB page", v23.

This patch series will free some vmemmap pages(struct page structures)
associated with each HugeTLB page when preallocated to save memory.

In order to reduce the difficulty of the first version of code review.  In
this version, we disable PMD/huge page mapping of vmemmap if this feature
was enabled.  This acutely eliminates a bunch of the complex code doing
page table manipulation.  When this patch series is solid, we cam add the
code of vmemmap page table manipulation in the future.

The struct page structures (page structs) are used to describe a physical
page frame.  By default, there is an one-to-one mapping from a page frame
to it's corresponding page struct.

The HugeTLB pages consist of multiple base page size pages and is
supported by many architectures.  See hugetlbpage.rst in the Documentation
directory for more details.  On the x86 architecture, HugeTLB pages of
size 2MB and 1GB are currently supported.  Since the base page size on x86
is 4KB, a 2MB HugeTLB page consists of 512 base pages and a 1GB HugeTLB
page consists of 4096 base pages.  For each base page, there is a
corresponding page struct.

Within the HugeTLB subsystem, only the first 4 page structs are used to
contain unique information about a HugeTLB page.  HUGETLB_CGROUP_MIN_ORDER
provides this upper limit.  The only 'useful' information in the remaining
page structs is the compound_head field, and this field is the same for
all tail pages.

By removing redundant page structs for HugeTLB pages, memory can returned
to the buddy allocator for other uses.

When the system boot up, every 2M HugeTLB has 512 struct page structs which
size is 8 pages(sizeof(struct page) * 512 / PAGE_SIZE).

    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
 +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
 |           |                     |     0     | -------------> |     0     |
 |           |                     +-----------+                +-----------+
 |           |                     |     1     | -------------> |     1     |
 |           |                     +-----------+                +-----------+
 |           |                     |     2     | -------------> |     2     |
 |           |                     +-----------+                +-----------+
 |           |                     |     3     | -------------> |     3     |
 |           |                     +-----------+                +-----------+
 |           |                     |     4     | -------------> |     4     |
 |    2MB    |                     +-----------+                +-----------+
 |           |                     |     5     | -------------> |     5     |
 |           |                     +-----------+                +-----------+
 |           |                     |     6     | -------------> |     6     |
 |           |                     +-----------+                +-----------+
 |           |                     |     7     | -------------> |     7     |
 |           |                     +-----------+                +-----------+
 |           |
 |           |
 |           |
 +-----------+

The value of page->compound_head is the same for all tail pages.  The
first page of page structs (page 0) associated with the HugeTLB page
contains the 4 page structs necessary to describe the HugeTLB.  The only
use of the remaining pages of page structs (page 1 to page 7) is to point
to page->compound_head.  Therefore, we can remap pages 2 to 7 to page 1.
Only 2 pages of page structs will be used for each HugeTLB page.  This
will allow us to free the remaining 6 pages to the buddy allocator.

Here is how things look after remapping.

    HugeTLB                  struct pages(8 pages)         page frame(8 pages)
 +-----------+ ---virt_to_page---> +-----------+   mapping to   +-----------+
 |           |                     |     0     | -------------> |     0     |
 |           |                     +-----------+                +-----------+
 |           |                     |     1     | -------------> |     1     |
 |           |                     +-----------+                +-----------+
 |           |                     |     2     | ----------------^ ^ ^ ^ ^ ^
 |           |                     +-----------+                   | | | | |
 |           |                     |     3     | ------------------+ | | | |
 |           |                     +-----------+                     | | | |
 |           |                     |     4     | --------------------+ | | |
 |    2MB    |                     +-----------+                       | | |
 |           |                     |     5     | ----------------------+ | |
 |           |                     +-----------+                         | |
 |           |                     |     6     | ------------------------+ |
 |           |                     +-----------+                           |
 |           |                     |     7     | --------------------------+
 |           |                     +-----------+
 |           |
 |           |
 |           |
 +-----------+

When a HugeTLB is freed to the buddy system, we should allocate 6 pages
for vmemmap pages and restore the previous mapping relationship.

Apart from 2MB HugeTLB page, we also have 1GB HugeTLB page.  It is similar
to the 2MB HugeTLB page.  We also can use this approach to free the
vmemmap pages.

In this case, for the 1GB HugeTLB page, we can save 4094 pages.  This is a
very substantial gain.  On our server, run some SPDK/QEMU applications
which will use 1024GB HugeTLB page.  With this feature enabled, we can
save ~16GB (1G hugepage)/~12GB (2MB hugepage) memory.

Because there are vmemmap page tables reconstruction on the
freeing/allocating path, it increases some overhead.  Here are some
overhead analysis.

1) Allocating 10240 2MB HugeTLB pages.

   a) With this patch series applied:
   # time echo 10240 > /proc/sys/vm/nr_hugepages

   real     0m0.166s
   user     0m0.000s
   sys      0m0.166s

   # bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; }
     kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [8K, 16K)           5476 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [16K, 32K)          4760 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@       |
   [32K, 64K)             4 |                                                    |

   b) Without this patch series:
   # time echo 10240 > /proc/sys/vm/nr_hugepages

   real     0m0.067s
   user     0m0.000s
   sys      0m0.067s

   # bpftrace -e 'kprobe:alloc_fresh_huge_page { @start[tid] = nsecs; }
     kretprobe:alloc_fresh_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [4K, 8K)           10147 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [8K, 16K)             93 |                                                    |

   Summarize: this feature is about ~2x slower than before.

2) Freeing 10240 2MB HugeTLB pages.

   a) With this patch series applied:
   # time echo 0 > /proc/sys/vm/nr_hugepages

   real     0m0.213s
   user     0m0.000s
   sys      0m0.213s

   # bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; }
     kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [8K, 16K)              6 |                                                    |
   [16K, 32K)         10227 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [32K, 64K)             7 |                                                    |

   b) Without this patch series:
   # time echo 0 > /proc/sys/vm/nr_hugepages

   real     0m0.081s
   user     0m0.000s
   sys      0m0.081s

   # bpftrace -e 'kprobe:free_pool_huge_page { @start[tid] = nsecs; }
     kretprobe:free_pool_huge_page /@start[tid]/ { @latency = hist(nsecs -
     @start[tid]); delete(@start[tid]); }'
   Attaching 2 probes...

   @latency:
   [4K, 8K)            6805 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
   [8K, 16K)           3427 |@@@@@@@@@@@@@@@@@@@@@@@@@@                          |
   [16K, 32K)             8 |                                                    |

   Summary: The overhead of __free_hugepage is about ~2-3x slower than before.

Although the overhead has increased, the overhead is not significant.
Like Mike said, "However, remember that the majority of use cases create
HugeTLB pages at or shortly after boot time and add them to the pool.  So,
additional overhead is at pool creation time.  There is no change to
'normal run time' operations of getting a page from or returning a page to
the pool (think page fault/unmap)".

Despite the overhead and in addition to the memory gains from this series.
The following data is obtained by Joao Martins.  Very thanks to his
effort.

There's an additional benefit which is page (un)pinners will see an improvement
and Joao presumes because there are fewer memmap pages and thus the tail/head
pages are staying in cache more often.

Out of the box Joao saw (when comparing linux-next against linux-next +
this series) with gup_test and pinning a 16G HugeTLB file (with 1G pages):

	get_user_pages(): ~32k -> ~9k
	unpin_user_pages(): ~75k -> ~70k

Usually any tight loop fetching compound_head(), or reading tail pages
data (e.g.  compound_head) benefit a lot.  There's some unpinning
inefficiencies Joao was fixing[2], but with that in added it shows even
more:

	unpin_user_pages(): ~27k -> ~3.8k

[1] https://lore.kernel.org/linux-mm/20210409205254.242291-1-mike.kravetz@oracle.com/
[2] https://lore.kernel.org/linux-mm/20210204202500.26474-1-joao.m.martins@oracle.com/

This patch (of 9):

Move bootmem info registration common API to individual bootmem_info.c.
And we will use {get,put}_page_bootmem() to initialize the page for the
vmemmap pages or free the vmemmap pages to buddy in the later patch.  So
move them out of CONFIG_MEMORY_HOTPLUG_SPARSE.  This is just code movement
without any functional change.

Link: https://lkml.kernel.org/r/20210510030027.56044-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20210510030027.56044-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Chen Huang <chenhuang5@huawei.com>
Tested-by: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Mina Almasry <almasrymina@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Barry Song <song.bao.hua@hisilicon.com>
Cc: HORIGUCHI NAOYA <naoya.horiguchi@nec.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-30 20:47:25 -07:00
Linus Torvalds
df668a5fe4 for-5.14/block-2021-06-29
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Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:

 - disk events cleanup (Christoph)

 - gendisk and request queue allocation simplifications (Christoph)

 - bdev_disk_changed cleanups (Christoph)

 - IO priority improvements (Bart)

 - Chained bio completion trace fix (Edward)

 - blk-wbt fixes (Jan)

 - blk-wbt enable/disable fix (Zhang)

 - Scheduler dispatch improvements (Jan, Ming)

 - Shared tagset scheduler improvements (John)

 - BFQ updates (Paolo, Luca, Pietro)

 - BFQ lock inversion fix (Jan)

 - Documentation improvements (Kir)

 - CLONE_IO block cgroup fix (Tejun)

 - Remove of ancient and deprecated block dump feature (zhangyi)

 - Discard merge fix (Ming)

 - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas,
   Yang)

* tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits)
  block: fix discard request merge
  block/mq-deadline: Remove a WARN_ON_ONCE() call
  blk-mq: update hctx->dispatch_busy in case of real scheduler
  blk: Fix lock inversion between ioc lock and bfqd lock
  bfq: Remove merged request already in bfq_requests_merged()
  block: pass a gendisk to bdev_disk_changed
  block: move bdev_disk_changed
  block: add the events* attributes to disk_attrs
  block: move the disk events code to a separate file
  block: fix trace completion for chained bio
  block/partitions/msdos: Fix typo inidicator -> indicator
  block, bfq: reset waker pointer with shared queues
  block, bfq: check waker only for queues with no in-flight I/O
  block, bfq: avoid delayed merge of async queues
  block, bfq: boost throughput by extending queue-merging times
  block, bfq: consider also creation time in delayed stable merge
  block, bfq: fix delayed stable merge check
  block, bfq: let also stably merged queues enjoy weight raising
  blk-wbt: make sure throttle is enabled properly
  blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled()
  ...
2021-06-30 12:12:56 -07:00
Mike Rapoport
023accf5cd memblock: ensure there is no overflow in memblock_overlaps_region()
There maybe an overflow in memblock_overlaps_region() if it is called with
base and size such that

	base + size > PHYS_ADDR_MAX

Make sure that memblock_overlaps_region() caps the size to prevent such
overflow and remove now duplicated call to memblock_cap_size() from
memblock_is_region_reserved().

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
2021-06-30 11:38:56 +03:00
Mike Rapoport
f921f53e08 memblock: align freed memory map on pageblock boundaries with SPARSEMEM
When CONFIG_SPARSEMEM=y the ranges of the memory map that are freed are not
aligned to the pageblock boundaries which breaks assumptions about
homogeneity of the memory map throughout core mm code.

Make sure that the freed memory map is always aligned on pageblock
boundaries regardless of the memory model selection.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
2021-06-30 11:38:51 +03:00
Mike Rapoport
e2a86800d5 memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER
The code that frees unused memory map uses rounds start and end of the
holes that are freed to MAX_ORDER_NR_PAGES to preserve continuity of the
memory map for MAX_ORDER regions.

Lots of core memory management functionality relies on homogeneity of the
memory map within each pageblock which size may differ from MAX_ORDER in
certain configurations.

Although currently, for the architectures that use free_unused_memmap(),
pageblock_order and MAX_ORDER are equivalent, it is cleaner to have common
notation thought mm code.

Replace MAX_ORDER_NR_PAGES with pageblock_nr_pages and update the comments
to make it more clear why the alignment to pageblock boundaries is
required.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
2021-06-30 11:38:33 +03:00
Linus Torvalds
65090f30ab Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "191 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, kernel/watchdog, and mm (gup, pagealloc, slab,
  slub, kmemleak, dax, debug, pagecache, gup, swap, memcg, pagemap,
  mprotect, bootmem, dma, tracing, vmalloc, kasan, initialization,
  pagealloc, and memory-failure)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (191 commits)
  mm,hwpoison: make get_hwpoison_page() call get_any_page()
  mm,hwpoison: send SIGBUS with error virutal address
  mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
  mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
  mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
  mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
  docs: remove description of DISCONTIGMEM
  arch, mm: remove stale mentions of DISCONIGMEM
  mm: remove CONFIG_DISCONTIGMEM
  m68k: remove support for DISCONTIGMEM
  arc: remove support for DISCONTIGMEM
  arc: update comment about HIGHMEM implementation
  alpha: remove DISCONTIGMEM and NUMA
  mm/page_alloc: move free_the_page
  mm/page_alloc: fix counting of managed_pages
  mm/page_alloc: improve memmap_pages dbg msg
  mm: drop SECTION_SHIFT in code comments
  mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
  mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
  mm/page_alloc: scale the number of pages that are batch freed
  ...
2021-06-29 17:29:11 -07:00
Naoya Horiguchi
0ed950d1f2 mm,hwpoison: make get_hwpoison_page() call get_any_page()
__get_hwpoison_page() could fail to grab refcount by some race condition,
so it's helpful if we can handle it by retrying.  We already have retry
logic, so make get_hwpoison_page() call get_any_page() when called from
memory_failure().

As a result, get_hwpoison_page() can return negative values (i.e.  error
code), so some callers are also changed to handle error cases.
soft_offline_page() does nothing for -EBUSY because that's enough and
users in userspace can easily handle it.  unpoison_memory() is also
unchanged because it's broken and need thorough fixes (will be done
later).

Link: https://lkml.kernel.org/r/20210603233632.2964832-3-nao.horiguchi@gmail.com
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:56 -07:00
Naoya Horiguchi
a3f5d80ea4 mm,hwpoison: send SIGBUS with error virutal address
Now an action required MCE in already hwpoisoned address surely sends a
SIGBUS to current process, but the SIGBUS doesn't convey error virtual
address.  That's not optimal for hwpoison-aware applications.

To fix the issue, make memory_failure() call kill_accessing_process(),
that does pagetable walk to find the error virtual address.  It could find
multiple virtual addresses for the same error page, and it seems hard to
tell which virtual address is correct one.  But that's rare and sending
incorrect virtual address could be better than no address.  So let's
report the first found virtual address for now.

[naoya.horiguchi@nec.com: fix walk_page_range() return]
  Link: https://lkml.kernel.org/r/20210603051055.GA244241@hori.linux.bs1.fc.nec.co.jp

Link: https://lkml.kernel.org/r/20210521030156.2612074-4-nao.horiguchi@gmail.com
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Aili Yao <yaoaili@kingsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jue Wang <juew@google.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mel Gorman
203c06eef5 mm/page_alloc: split pcp->high across all online CPUs for cpuless nodes
Dave Hansen reported the following about Feng Tang's tests on a machine
with persistent memory onlined as a DRAM-like device.

  Feng Tang tossed these on a "Cascade Lake" system with 96 threads and
  ~512G of persistent memory and 128G of DRAM.  The PMEM is in "volatile
  use" mode and being managed via the buddy just like the normal RAM.

  The PMEM zones are big ones:

        present  65011712 = 248 G
        high       134595 = 525 M

  The PMEM nodes, of course, don't have any CPUs in them.

  With your series, the pcp->high value per-cpu is 69584 pages or about
  270MB per CPU.  Scaled up by the 96 CPU threads, that's ~26GB of
  worst-case memory in the pcps per zone, or roughly 10% of the size of
  the zone.

This should not cause a problem as such although it could trigger reclaim
due to pages being stored on per-cpu lists for CPUs remote to a node.  It
is not possible to treat cpuless nodes exactly the same as normal nodes
but the worst-case scenario can be mitigated by splitting pcp->high across
all online CPUs for cpuless memory nodes.

Link: https://lkml.kernel.org/r/20210616110743.GK30378@techsingularity.net
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Tang, Feng" <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mel Gorman
44042b4498 mm/page_alloc: allow high-order pages to be stored on the per-cpu lists
The per-cpu page allocator (PCP) only stores order-0 pages.  This means
that all THP and "cheap" high-order allocations including SLUB contends on
the zone->lock.  This patch extends the PCP allocator to store THP and
"cheap" high-order pages.  Note that struct per_cpu_pages increases in
size to 256 bytes (4 cache lines) on x86-64.

Note that this is not necessarily a universal performance win because of
how it is implemented.  High-order pages can cause pcp->high to be
exceeded prematurely for lower-orders so for example, a large number of
THP pages being freed could release order-0 pages from the PCP lists.
Hence, much depends on the allocation/free pattern as observed by a single
CPU to determine if caching helps or hurts a particular workload.

That said, basic performance testing passed.  The following is a netperf
UDP_STREAM test which hits the relevant patches as some of the network
allocations are high-order.

netperf-udp
                                 5.13.0-rc2             5.13.0-rc2
                           mm-pcpburst-v3r4   mm-pcphighorder-v1r7
Hmean     send-64         261.46 (   0.00%)      266.30 *   1.85%*
Hmean     send-128        516.35 (   0.00%)      536.78 *   3.96%*
Hmean     send-256       1014.13 (   0.00%)     1034.63 *   2.02%*
Hmean     send-1024      3907.65 (   0.00%)     4046.11 *   3.54%*
Hmean     send-2048      7492.93 (   0.00%)     7754.85 *   3.50%*
Hmean     send-3312     11410.04 (   0.00%)    11772.32 *   3.18%*
Hmean     send-4096     13521.95 (   0.00%)    13912.34 *   2.89%*
Hmean     send-8192     21660.50 (   0.00%)    22730.72 *   4.94%*
Hmean     send-16384    31902.32 (   0.00%)    32637.50 *   2.30%*

Functionally, a patch like this is necessary to make bulk allocation of
high-order pages work with similar performance to order-0 bulk
allocations.  The bulk allocator is not updated in this series as it would
have to be determined by bulk allocation users how they want to track the
order of pages allocated with the bulk allocator.

Link: https://lkml.kernel.org/r/20210611135753.GC30378@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mike Rapoport
43b02ba93b mm: replace CONFIG_FLAT_NODE_MEM_MAP with CONFIG_FLATMEM
After removal of the DISCONTIGMEM memory model the FLAT_NODE_MEM_MAP
configuration option is equivalent to FLATMEM.

Drop CONFIG_FLAT_NODE_MEM_MAP and use CONFIG_FLATMEM instead.

Link: https://lkml.kernel.org/r/20210608091316.3622-10-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mike Rapoport
a9ee6cf5c6 mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA
configuration options are equivalent.

Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead.

Done with

	$ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \
		$(git grep -wl CONFIG_NEED_MULTIPLE_NODES)
	$ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \
		$(git grep -wl NEED_MULTIPLE_NODES)

with manual tweaks afterwards.

[rppt@linux.ibm.com: fix arm boot crash]
  Link: https://lkml.kernel.org/r/YMj9vHhHOiCVN4BF@linux.ibm.com

Link: https://lkml.kernel.org/r/20210608091316.3622-9-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mike Rapoport
bb1c50d396 mm: remove CONFIG_DISCONTIGMEM
There are no architectures that support DISCONTIGMEM left.

Remove the configuration option and the dead code it was guarding in the
generic memory management code.

Link: https://lkml.kernel.org/r/20210608091316.3622-6-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mel Gorman
21d02f8f84 mm/page_alloc: move free_the_page
Patch series "Allow high order pages to be stored on PCP", v2.

The per-cpu page allocator (PCP) only handles order-0 pages.  With the
series "Use local_lock for pcp protection and reduce stat overhead" and
"Calculate pcp->high based on zone sizes and active CPUs", it's now
feasible to store high-order pages on PCP lists.

This small series allows PCP to store "cheap" orders where cheap is
determined by PAGE_ALLOC_COSTLY_ORDER and THP-sized allocations.

This patch (of 2):

In the next page, free_compount_page is going to use the common helper
free_the_page.  This patch moves the definition to ease review.  No
functional change.

Link: https://lkml.kernel.org/r/20210603142220.10851-1-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20210603142220.10851-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Liu Shixin
f7ec104458 mm/page_alloc: fix counting of managed_pages
commit f63661566f ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if
the zone is empty") clears out zone->lowmem_reserve[] if zone is empty.
But when zone is not empty and sysctl_lowmem_reserve_ratio[i] is set to
zero, zone_managed_pages(zone) is not counted in the managed_pages either.
This is inconsistent with the description of lowmem_reserve, so fix it.

Link: https://lkml.kernel.org/r/20210527125707.3760259-1-liushixin2@huawei.com
Fixes: f63661566f ("mm/page_alloc.c: clear out zone->lowmem_reserve[] if the zone is empty")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reported-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Dong Aisheng
e47aa90568 mm/page_alloc: improve memmap_pages dbg msg
Make debug message more accurate.

Link: https://lkml.kernel.org/r/20210531091908.1738465-6-aisheng.dong@nxp.com
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mel Gorman
74f4482209 mm/page_alloc: introduce vm.percpu_pagelist_high_fraction
This introduces a new sysctl vm.percpu_pagelist_high_fraction.  It is
similar to the old vm.percpu_pagelist_fraction.  The old sysctl increased
both pcp->batch and pcp->high with the higher pcp->high potentially
reducing zone->lock contention.  However, the higher pcp->batch value also
potentially increased allocation latency while the PCP was refilled.  This
sysctl only adjusts pcp->high so that zone->lock contention is potentially
reduced but allocation latency during a PCP refill remains the same.

  # grep -E "high:|batch" /proc/zoneinfo | tail -2
              high:  649
              batch: 63

  # sysctl vm.percpu_pagelist_high_fraction=8
  # grep -E "high:|batch" /proc/zoneinfo | tail -2
              high:  35071
              batch: 63

  # sysctl vm.percpu_pagelist_high_fraction=64
              high:  4383
              batch: 63

  # sysctl vm.percpu_pagelist_high_fraction=0
              high:  649
              batch: 63

[mgorman@techsingularity.net: fix documentation]
  Link: https://lkml.kernel.org/r/20210528151010.GQ30378@techsingularity.net

Link: https://lkml.kernel.org/r/20210525080119.5455-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mel Gorman
c49c2c47da mm/page_alloc: limit the number of pages on PCP lists when reclaim is active
When kswapd is active then direct reclaim is potentially active.  In
either case, it is possible that a zone would be balanced if pages were
not trapped on PCP lists.  Instead of draining remote pages, simply limit
the size of the PCP lists while kswapd is active.

Link: https://lkml.kernel.org/r/20210525080119.5455-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
3b12e7e979 mm/page_alloc: scale the number of pages that are batch freed
When a task is freeing a large number of order-0 pages, it may acquire the
zone->lock multiple times freeing pages in batches.  This may
unnecessarily contend on the zone lock when freeing very large number of
pages.  This patch adapts the size of the batch based on the recent
pattern to scale the batch size for subsequent frees.

As the machines I used were not large enough to test this are not large
enough to illustrate a problem, a debugging patch shows patterns like the
following (slightly editted for clarity)

Baseline vanilla kernel
  time-unmap-14426   [...] free_pcppages_bulk: free   63 count  378 high  378
  time-unmap-14426   [...] free_pcppages_bulk: free   63 count  378 high  378
  time-unmap-14426   [...] free_pcppages_bulk: free   63 count  378 high  378
  time-unmap-14426   [...] free_pcppages_bulk: free   63 count  378 high  378
  time-unmap-14426   [...] free_pcppages_bulk: free   63 count  378 high  378

With patches
  time-unmap-7724    [...] free_pcppages_bulk: free  126 count  814 high  814
  time-unmap-7724    [...] free_pcppages_bulk: free  252 count  814 high  814
  time-unmap-7724    [...] free_pcppages_bulk: free  504 count  814 high  814
  time-unmap-7724    [...] free_pcppages_bulk: free  751 count  814 high  814
  time-unmap-7724    [...] free_pcppages_bulk: free  751 count  814 high  814

Link: https://lkml.kernel.org/r/20210525080119.5455-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
04f8cfeaed mm/page_alloc: adjust pcp->high after CPU hotplug events
The PCP high watermark is based on the number of online CPUs so the
watermarks must be adjusted during CPU hotplug.  At the time of
hot-remove, the number of online CPUs is already adjusted but during
hot-add, a delta needs to be applied to update PCP to the correct value.
After this patch is applied, the high watermarks are adjusted correctly.

  # grep high: /proc/zoneinfo  | tail -1
              high:  649
  # echo 0 > /sys/devices/system/cpu/cpu4/online
  # grep high: /proc/zoneinfo  | tail -1
              high:  664
  # echo 1 > /sys/devices/system/cpu/cpu4/online
  # grep high: /proc/zoneinfo  | tail -1
              high:  649

Link: https://lkml.kernel.org/r/20210525080119.5455-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
b92ca18e8c mm/page_alloc: disassociate the pcp->high from pcp->batch
The pcp high watermark is based on the batch size but there is no
relationship between them other than it is convenient to use early in
boot.

This patch takes the first step and bases pcp->high on the zone low
watermark split across the number of CPUs local to a zone while the batch
size remains the same to avoid increasing allocation latencies.  The
intent behind the default pcp->high is "set the number of PCP pages such
that if they are all full that background reclaim is not started
prematurely".

Note that in this patch the pcp->high values are adjusted after memory
hotplug events, min_free_kbytes adjustments and watermark scale factor
adjustments but not CPU hotplug events which is handled later in the
series.

On a test KVM instance;

Before grep -E "high:|batch" /proc/zoneinfo | tail -2
              high:  378
              batch: 63

After grep -E "high:|batch" /proc/zoneinfo | tail -2
              high:  649
              batch: 63

[mgorman@techsingularity.net:  fix __setup_per_zone_wmarks for parallel memory
hotplug]
  Link: https://lkml.kernel.org/r/20210528105925.GN30378@techsingularity.net

Link: https://lkml.kernel.org/r/20210525080119.5455-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
bbbecb35a4 mm/page_alloc: delete vm.percpu_pagelist_fraction
Patch series "Calculate pcp->high based on zone sizes and active CPUs", v2.

The per-cpu page allocator (PCP) is meant to reduce contention on the zone
lock but the sizing of batch and high is archaic and neither takes the
zone size into account or the number of CPUs local to a zone.  With larger
zones and more CPUs per node, the contention is getting worse.
Furthermore, the fact that vm.percpu_pagelist_fraction adjusts both batch
and high values means that the sysctl can reduce zone lock contention but
also increase allocation latencies.

This series disassociates pcp->high from pcp->batch and then scales
pcp->high based on the size of the local zone with limited impact to
reclaim and accounting for active CPUs but leaves pcp->batch static.  It
also adapts the number of pages that can be on the pcp list based on
recent freeing patterns.

The motivation is partially to adjust to larger memory sizes but is also
driven by the fact that large batches of page freeing via release_pages()
often shows zone contention as a major part of the problem.  Another is a
bug report based on an older kernel where a multi-terabyte process can
takes several minutes to exit.  A workaround was to use
vm.percpu_pagelist_fraction to increase the pcp->high value but testing
indicated that a production workload could not use the same values because
of an increase in allocation latencies.  Unfortunately, I cannot reproduce
this test case myself as the multi-terabyte machines are in active use but
it should alleviate the problem.

The series aims to address both and partially acts as a pre-requisite.
pcp only works with order-0 which is useless for SLUB (when using high
orders) and THP (unconditionally).  To store high-order pages on PCP, the
pcp->high values need to be increased first.

This patch (of 6):

The vm.percpu_pagelist_fraction is used to increase the batch and high
limits for the per-cpu page allocator (PCP).  The intent behind the sysctl
is to reduce zone lock acquisition when allocating/freeing pages but it
has a problem.  While it can decrease contention, it can also increase
latency on the allocation side due to unreasonably large batch sizes.
This leads to games where an administrator adjusts
percpu_pagelist_fraction on the fly to work around contention and
allocation latency problems.

This series aims to alleviate the problems with zone lock contention while
avoiding the allocation-side latency problems.  For the purposes of
review, it's easier to remove this sysctl now and reintroduce a similar
sysctl later in the series that deals only with pcp->high.

Link: https://lkml.kernel.org/r/20210525080119.5455-1-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20210525080119.5455-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Minchan Kim
151e084af4 mm: page_alloc: dump migrate-failed pages only at -EBUSY
alloc_contig_dump_pages() aims for helping debugging page migration
failure by elevated page refcount compared to expected_count.  (for the
detail, please look at migrate_page_move_mapping)

However, -ENOMEM is just the case that system is under memory pressure
state, not relevant with page refcount at all.  Thus, the dumping page
list is not helpful for the debugging point of view.

Link: https://lkml.kernel.org/r/YKa2Wyo9xqIErpfa@google.com
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: John Dias <joaodias@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
902499937e mm/page_alloc: update PGFREE outside the zone lock in __free_pages_ok
VM events do not need explicit protection by disabling IRQs so update the
counter with IRQs enabled in __free_pages_ok.

Link: https://lkml.kernel.org/r/20210512095458.30632-10-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
df1acc8569 mm/page_alloc: avoid conflating IRQs disabled with zone->lock
Historically when freeing pages, free_one_page() assumed that callers had
IRQs disabled and the zone->lock could be acquired with spin_lock().  This
confuses the scope of what local_lock_irq is protecting and what
zone->lock is protecting in free_unref_page_list in particular.

This patch uses spin_lock_irqsave() for the zone->lock in free_one_page()
instead of relying on callers to have disabled IRQs.
free_unref_page_commit() is changed to only deal with PCP pages protected
by the local lock.  free_unref_page_list() then first frees isolated pages
to the buddy lists with free_one_page() and frees the rest of the pages to
the PCP via free_unref_page_commit().  The end result is that
free_one_page() is no longer depending on side-effects of local_lock to be
correct.

Note that this may incur a performance penalty while memory hot-remove is
running but that is not a common operation.

[lkp@intel.com: Ensure CMA pages get addded to correct pcp list]

Link: https://lkml.kernel.org/r/20210512095458.30632-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
56f0e661ea mm/page_alloc: explicitly acquire the zone lock in __free_pages_ok
__free_pages_ok() disables IRQs before calling a common helper
free_one_page() that acquires the zone lock.  This is not safe according
to Documentation/locking/locktypes.rst and in this context, IRQ disabling
is not protecting a per_cpu_pages structure either or a local_lock would
be used.

This patch explicitly acquires the lock with spin_lock_irqsave instead of
relying on a helper.  This removes the last instance of local_irq_save()
in page_alloc.c.

Link: https://lkml.kernel.org/r/20210512095458.30632-8-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
43c95bcc51 mm/page_alloc: reduce duration that IRQs are disabled for VM counters
IRQs are left disabled for the zone and node VM event counters.  This is
unnecessary as the affected counters are allowed to race for preemmption
and IRQs.

This patch reduces the scope of IRQs being disabled via
local_[lock|unlock]_irq on !PREEMPT_RT kernels.  One
__mod_zone_freepage_state is still called with IRQs disabled.  While this
could be moved out, it's not free on all architectures as some require
IRQs to be disabled for mod_zone_page_state on !PREEMPT_RT kernels.

Link: https://lkml.kernel.org/r/20210512095458.30632-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
3e23060b2d mm/page_alloc: batch the accounting updates in the bulk allocator
Now that the zone_statistics are simple counters that do not require
special protection, the bulk allocator accounting updates can be batch
updated without adding too much complexity with protected RMW updates or
using xchg.

Link: https://lkml.kernel.org/r/20210512095458.30632-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
3ac44a346a mm/vmstat: inline NUMA event counter updates
__count_numa_event is small enough to be treated similarly to
__count_vm_event so inline it.

Link: https://lkml.kernel.org/r/20210512095458.30632-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
f19298b951 mm/vmstat: convert NUMA statistics to basic NUMA counters
NUMA statistics are maintained on the zone level for hits, misses, foreign
etc but nothing relies on them being perfectly accurate for functional
correctness.  The counters are used by userspace to get a general overview
of a workloads NUMA behaviour but the page allocator incurs a high cost to
maintain perfect accuracy similar to what is required for a vmstat like
NR_FREE_PAGES.  There even is a sysctl vm.numa_stat to allow userspace to
turn off the collection of NUMA statistics like NUMA_HIT.

This patch converts NUMA_HIT and friends to be NUMA events with similar
accuracy to VM events.  There is a possibility that slight errors will be
introduced but the overall trend as seen by userspace will be similar.
The counters are no longer updated from vmstat_refresh context as it is
unnecessary overhead for counters that may never be read by userspace.
Note that counters could be maintained at the node level to save space but
it would have a user-visible impact due to /proc/zoneinfo.

[lkp@intel.com: Fix misplaced closing brace for !CONFIG_NUMA]

Link: https://lkml.kernel.org/r/20210512095458.30632-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
dbbee9d5cd mm/page_alloc: convert per-cpu list protection to local_lock
There is a lack of clarity of what exactly
local_irq_save/local_irq_restore protects in page_alloc.c .  It conflates
the protection of per-cpu page allocation structures with per-cpu vmstat
deltas.

This patch protects the PCP structure using local_lock which for most
configurations is identical to IRQ enabling/disabling.  The scope of the
lock is still wider than it should be but this is decreased later.

It is possible for the local_lock to be embedded safely within struct
per_cpu_pages but it adds complexity to free_unref_page_list.

[akpm@linux-foundation.org: coding style fixes]
[mgorman@techsingularity.net: work around a pahole limitation with zero-sized struct pagesets]
  Link: https://lkml.kernel.org/r/20210526080741.GW30378@techsingularity.net
[lkp@intel.com: Make pagesets static]

Link: https://lkml.kernel.org/r/20210512095458.30632-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Mel Gorman
28f836b677 mm/page_alloc: split per cpu page lists and zone stats
The PCP (per-cpu page allocator in page_alloc.c) shares locking
requirements with vmstat and the zone lock which is inconvenient and
causes some issues.  For example, the PCP list and vmstat share the same
per-cpu space meaning that it's possible that vmstat updates dirty cache
lines holding per-cpu lists across CPUs unless padding is used.  Second,
PREEMPT_RT does not want to disable IRQs for too long in the page
allocator.

This series splits the locking requirements and uses locks types more
suitable for PREEMPT_RT, reduces the time when special locking is required
for stats and reduces the time when IRQs need to be disabled on
!PREEMPT_RT kernels.

Why local_lock?  PREEMPT_RT considers the following sequence to be unsafe
as documented in Documentation/locking/locktypes.rst

   local_irq_disable();
   spin_lock(&lock);

The pcp allocator has this sequence for rmqueue_pcplist (local_irq_save)
-> __rmqueue_pcplist -> rmqueue_bulk (spin_lock).  While it's possible to
separate this out, it generally means there are points where we enable
IRQs and reenable them again immediately.  To prevent a migration and the
per-cpu pointer going stale, migrate_disable is also needed.  That is a
custom lock that is similar, but worse, than local_lock.  Furthermore, on
PREEMPT_RT, it's undesirable to leave IRQs disabled for too long.  By
converting to local_lock which disables migration on PREEMPT_RT, the
locking requirements can be separated and start moving the protections for
PCP, stats and the zone lock to PREEMPT_RT-safe equivalent locking.  As a
bonus, local_lock also means that PROVE_LOCKING does something useful.

After that, it's obvious that zone_statistics incurs too much overhead and
leaves IRQs disabled for longer than necessary on !PREEMPT_RT kernels.
zone_statistics uses perfectly accurate counters requiring IRQs be
disabled for parallel RMW sequences when inaccurate ones like vm_events
would do.  The series makes the NUMA statistics (NUMA_HIT and friends)
inaccurate counters that then require no special protection on
!PREEMPT_RT.

The bulk page allocator can then do stat updates in bulk with IRQs enabled
which should improve the efficiency.  Technically, this could have been
done without the local_lock and vmstat conversion work and the order
simply reflects the timing of when different series were implemented.

Finally, there are places where we conflate IRQs being disabled for the
PCP with the IRQ-safe zone spinlock.  The remainder of the series reduces
the scope of what is protected by disabled IRQs on !PREEMPT_RT kernels.
By the end of the series, page_alloc.c does not call local_irq_save so the
locking scope is a bit clearer.  The one exception is that modifying
NR_FREE_PAGES still happens in places where it's known the IRQs are
disabled as it's harmless for PREEMPT_RT and would be expensive to split
the locking there.

No performance data is included because despite the overhead of the stats,
it's within the noise for most workloads on !PREEMPT_RT.  However, Jesper
Dangaard Brouer ran a page allocation microbenchmark on a E5-1650 v4 @
3.60GHz CPU on the first version of this series.  Focusing on the array
variant of the bulk page allocator reveals the following.

(CPU: Intel(R) Xeon(R) CPU E5-1650 v4 @ 3.60GHz)
ARRAY variant: time_bulk_page_alloc_free_array: step=bulk size

         Baseline        Patched
 1       56.383          54.225 (+3.83%)
 2       40.047          35.492 (+11.38%)
 3       37.339          32.643 (+12.58%)
 4       35.578          30.992 (+12.89%)
 8       33.592          29.606 (+11.87%)
 16      32.362          28.532 (+11.85%)
 32      31.476          27.728 (+11.91%)
 64      30.633          27.252 (+11.04%)
 128     30.596          27.090 (+11.46%)

While this is a positive outcome, the series is more likely to be
interesting to the RT people in terms of getting parts of the PREEMPT_RT
tree into mainline.

This patch (of 9):

The per-cpu page allocator lists and the per-cpu vmstat deltas are stored
in the same struct per_cpu_pages even though vmstats have no direct impact
on the per-cpu page lists.  This is inconsistent because the vmstats for a
node are stored on a dedicated structure.  The bigger issue is that the
per_cpu_pages structure is not cache-aligned and stat updates either cache
conflict with adjacent per-cpu lists incurring a runtime cost or padding
is required incurring a memory cost.

This patch splits the per-cpu pagelists and the vmstat deltas into
separate structures.  It's mostly a mechanical conversion but some
variable renaming is done to clearly distinguish the per-cpu pages
structure (pcp) from the vmstats (pzstats).

Superficially, this appears to increase the size of the per_cpu_pages
structure but the movement of expire fills a structure hole so there is no
impact overall.

[mgorman@techsingularity.net: make it W=1 cleaner]
  Link: https://lkml.kernel.org/r/20210514144622.GA3735@techsingularity.net
[mgorman@techsingularity.net: make it W=1 even cleaner]
  Link: https://lkml.kernel.org/r/20210516140705.GB3735@techsingularity.net
[lkp@intel.com: check struct per_cpu_zonestat has a non-zero size]
[vbabka@suse.cz: Init zone->per_cpu_zonestats properly]

Link: https://lkml.kernel.org/r/20210512095458.30632-1-mgorman@techsingularity.net
Link: https://lkml.kernel.org/r/20210512095458.30632-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:54 -07:00
Heiner Kallweit
9660ecaa79 mm/page_alloc: switch to pr_debug
Having such debug messages in the dmesg log may confuse users.  Therefore
restrict debug output to cases where DEBUG is defined or dynamic debugging
is enabled for the respective code piece.

Link: https://lkml.kernel.org/r/976adb93-3041-ce63-48fc-55a6096a51c1@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Matthew Wilcox (Oracle)
ca891f41c4 mm: constify get_pfnblock_flags_mask and get_pfnblock_migratetype
The struct page is not modified by these routines, so it can be marked
const.

Link: https://lkml.kernel.org/r/20210416231531.2521383-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Matthew Wilcox (Oracle)
8bf6f451bd mm/page_owner: constify dump_page_owner
dump_page_owner() only uses struct page to find the page_ext, and
lookup_page_ext() already takes a const argument.

Link: https://lkml.kernel.org/r/20210416231531.2521383-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Matthew Wilcox (Oracle)
be7c701fd4 mm/debug: factor PagePoisoned out of __dump_page
Move the PagePoisoned test into dump_page().  Skip the hex print for
poisoned pages -- we know they're full of ffffffff.  Move the reason
printing from __dump_page() to dump_page().

Link: https://lkml.kernel.org/r/20210416231531.2521383-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Aaron Tomlin
691d949728 mm/page_alloc: bail out on fatal signal during reclaim/compaction retry attempt
A customer experienced a low-memory situation and decided to issue a
SIGKILL (i.e.  a fatal signal).  Instead of promptly terminating as one
would expect, the aforementioned task remained unresponsive.

Further investigation indicated that the task was "stuck" in the
reclaim/compaction retry loop.  Now, it does not make sense to retry
compaction when a fatal signal is pending.

In the context of try_to_compact_pages(), indeed COMPACT_SKIPPED can be
returned; albeit, not every zone, on the zone list, would be considered in
the case a fatal signal is found to be pending.  Yet, in
should_compact_retry(), given the last known compaction result, each zone,
on the zone list, can be considered/or checked (see
compaction_zonelist_suitable()).  For example, if a zone was found to
succeed, then reclaim/compaction would be tried again (notwithstanding the
above).

This patch ensures that compaction is not needlessly retried irrespective
of the last known compaction result e.g.  if it was skipped, in the
unlikely case a fatal signal is found pending.  So, OOM is at least
attempted.

Link: https://lkml.kernel.org/r/20210520142901.3371299-1-atomlin@redhat.com
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Matthew Wilcox (Oracle)
d2f07ec052 mm: make __dump_page static
Patch series "Constify struct page arguments".

While working on various solutions to the 32-bit struct page size
regression, one of the problems I found was the networking stack expects
to be able to pass const struct page pointers around, and the mm doesn't
provide a lot of const-friendly functions to call.  The root tangle of
problems is that a lot of functions call VM_BUG_ON_PAGE(), which calls
dump_page(), which calls a lot of functions which don't take a const
struct page (but could be const).

This patch (of 6):

The only caller of __dump_page() now opencodes dump_page(), so remove it
as an externally visible symbol.

Link: https://lkml.kernel.org/r/20210416231531.2521383-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20210416231531.2521383-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Kuan-Ying Lee
7a22bdc3c4 kasan: add memory corruption identification support for hardware tag-based mode
Add memory corruption identification support for hardware tag-based mode.
We store one old free pointer tag and free backtrace instead of five
because hardware tag-based kasan only has 16 different tags.

If we store as many stacks as SW tag-based kasan does(5 stacks), there is
high probability to find the same tag in the stacks when out-of-bound
issues happened and we will mistake out-of-bound issue for use-after-free.

Link: https://lkml.kernel.org/r/20210626100931.22794-4-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Kuan-Ying Lee
a0503b8a0b kasan: integrate the common part of two KASAN tag-based modes
1. Move kasan_get_free_track() and kasan_set_free_info() into tags.c
   and combine these two functions for SW_TAGS and HW_TAGS kasan mode.

2. Move kasan_get_bug_type() to report_tags.c and make this function
   compatible for SW_TAGS and HW_TAGS kasan mode.

Link: https://lkml.kernel.org/r/20210626100931.22794-3-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Kuan-Ying Lee
f06f78ab48 kasan: rename CONFIG_KASAN_SW_TAGS_IDENTIFY to CONFIG_KASAN_TAGS_IDENTIFY
Patch series "kasan: add memory corruption identification support for hw tag-based kasan", v4.

Add memory corruption identification for hardware tag-based KASAN mode.

This patch (of 3):

Rename CONFIG_KASAN_SW_TAGS_IDENTIFY to CONFIG_KASAN_TAGS_IDENTIFY in
order to be compatible with hardware tag-based mode.

Link: https://lkml.kernel.org/r/20210626100931.22794-1-Kuan-Ying.Lee@mediatek.com
Link: https://lkml.kernel.org/r/20210626100931.22794-2-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Daniel Axtens
cb32c9c5d4 kasan: use MAX_PTRS_PER_* for early shadow tables
powerpc has a variable number of PTRS_PER_*, set at runtime based on the
MMU that the kernel is booted under.

This means the PTRS_PER_* are no longer constants, and therefore breaks
the build.  Switch to using MAX_PTRS_PER_*, which are constant.

Link: https://lkml.kernel.org/r/20210624034050.511391-5-dja@axtens.net
Signed-off-by: Daniel Axtens <dja@axtens.net>
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Daniel Axtens
af3751f3c2 kasan: allow architectures to provide an outline readiness check
Allow architectures to define a kasan_arch_is_ready() hook that bails out
of any function that's about to touch the shadow unless the arch says that
it is ready for the memory to be accessed.  This is fairly uninvasive and
should have a negligible performance penalty.

This will only work in outline mode, so an arch must specify
ARCH_DISABLE_KASAN_INLINE if it requires this.

Link: https://lkml.kernel.org/r/20210624034050.511391-3-dja@axtens.net
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Marco Elver <elver@google.com>
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Alexander Potapenko
336abff6e8 kasan: use dump_stack_lvl(KERN_ERR) to print stacks
Most of the contents of KASAN reports are printed with pr_err(), so use a
consistent logging level to print the memory access stacks.

Link: https://lkml.kernel.org/r/20210506105405.3535023-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Prasad Sodagudi <psodagud@quicinc.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: he, bo <bo.he@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:52 -07:00
Rafael Aquini
a850e932df mm: vmalloc: add cond_resched() in __vunmap()
On non-preemptible kernel builds the watchdog can complain about soft
lockups when vfree() is called against large vmalloc areas:

[  210.851798] kvmalloc-test: vmalloc(2199023255552) succeeded
[  238.654842] watchdog: BUG: soft lockup - CPU#181 stuck for 26s! [rmmod:5203]
[  238.662716] Modules linked in: kvmalloc_test(OE-) ...
[  238.772671] CPU: 181 PID: 5203 Comm: rmmod Tainted: G S         OE     5.13.0-rc7+ #1
[  238.781413] Hardware name: Intel Corporation PURLEY/PURLEY, BIOS PLYXCRB1.86B.0553.D01.1809190614 09/19/2018
[  238.792383] RIP: 0010:free_unref_page+0x52/0x60
[  238.797447] Code: 48 c1 fd 06 48 89 ee e8 9c d0 ff ff 84 c0 74 19 9c 41 5c fa 48 89 ee 48 89 df e8 b9 ea ff ff 41 f7 c4 00 02 00 00 74 01 fb 5b <5d> 41 5c c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f0 29 77
[  238.818406] RSP: 0018:ffffb4d87868fe98 EFLAGS: 00000206
[  238.824236] RAX: 0000000000000000 RBX: 000000001da0c945 RCX: ffffb4d87868fe40
[  238.832200] RDX: ffffd79d3beed108 RSI: ffffd7998501dc08 RDI: ffff9c6fbffd7010
[  238.840166] RBP: 000000000d518cbd R08: ffffd7998501dc08 R09: 0000000000000001
[  238.848131] R10: 0000000000000000 R11: ffffd79d3beee088 R12: 0000000000000202
[  238.856095] R13: ffff9e5be3eceec0 R14: 0000000000000000 R15: 0000000000000000
[  238.864059] FS:  00007fe082c2d740(0000) GS:ffff9f4c69b40000(0000) knlGS:0000000000000000
[  238.873089] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  238.879503] CR2: 000055a000611128 CR3: 000000f6094f6006 CR4: 00000000007706e0
[  238.887467] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  238.895433] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  238.903397] PKRU: 55555554
[  238.906417] Call Trace:
[  238.909149]  __vunmap+0x17c/0x220
[  238.912851]  __x64_sys_delete_module+0x13a/0x250
[  238.918008]  ? syscall_trace_enter.isra.20+0x13c/0x1b0
[  238.923746]  do_syscall_64+0x39/0x80
[  238.927740]  entry_SYSCALL_64_after_hwframe+0x44/0xae

Like in other range zapping routines that iterate over a large list, lets
just add cond_resched() within __vunmap()'s page-releasing loop in order
to avoid the watchdog splats.

Link: https://lkml.kernel.org/r/20210622225030.478384-1-aquini@redhat.com
Signed-off-by: Rafael Aquini <aquini@redhat.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:52 -07:00
Uladzislau Rezki
12b9f873a5 mm/vmalloc: fallback to a single page allocator
Currently for order-0 pages we use a bulk-page allocator to get set of
pages.  From the other hand not allocating all pages is something that
might occur.  In that case we should fallbak to the single-page allocator
trying to get missing pages, because it is more permissive(direct reclaim,
etc).

Introduce a vm_area_alloc_pages() function where the described logic is
implemented.

Link: https://lkml.kernel.org/r/20210521130718.GA17882@pc638.lan
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:52 -07:00
Uladzislau Rezki (Sony)
f4bdfeaf18 mm/vmalloc: remove quoted strings split across lines
A checkpatch.pl script complains on splitting a text across lines.  It is
because if a user wants to find an entire string he or she will not
succeeded.

<snip>
WARNING: quoted string split across lines
+               "vmalloc size %lu allocation failure: "
+               "page order %u allocation failed",

total: 0 errors, 1 warnings, 10 lines checked
<snip>

Link: https://lkml.kernel.org/r/20210521204359.19943-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:52 -07:00
Uladzislau Rezki (Sony)
cd61413baa mm/vmalloc: print a warning message first on failure
When a memory allocation for array of pages are not succeed emit a warning
message as a first step and then perform the further cleanup.

The reason it should be done in a right order is the clean up function
which is free_vm_area() can potentially also follow its error paths what
can lead to confusion what was broken first.

Link: https://lkml.kernel.org/r/20210516202056.2120-4-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:52 -07:00
Uladzislau Rezki (Sony)
5c1f4e690e mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()
Recently there has been introduced a page bulk allocator for users which
need to get number of pages per one call request.

For order-0 pages switch to an alloc_pages_bulk_array_node() instead of
alloc_pages_node(), the reason is the former is not capable of allocating
set of pages, thus a one call is per one page.

Second, according to my tests the bulk allocator uses less cycles even for
scenarios when only one page is requested.  Running the "perf" on same
test case shows below difference:

<default>
  - 45.18% __vmalloc_node
     - __vmalloc_node_range
        - 35.60% __alloc_pages
           - get_page_from_freelist
                3.36% __list_del_entry_valid
                3.00% check_preemption_disabled
                1.42% prep_new_page
<default>

<patch>
  - 31.00% __vmalloc_node
     - __vmalloc_node_range
        - 14.48% __alloc_pages_bulk
             3.22% __list_del_entry_valid
           - 0.83% __alloc_pages
                get_page_from_freelist
<patch>

The "test_vmalloc.sh" also shows performance improvements:

fix_size_alloc_test_4MB   loops: 1000000 avg: 89105095 usec
fix_size_alloc_test       loops: 1000000 avg: 513672   usec
full_fit_alloc_test       loops: 1000000 avg: 748900   usec
long_busy_list_alloc_test loops: 1000000 avg: 8043038  usec
random_size_alloc_test    loops: 1000000 avg: 4028582  usec
fix_align_alloc_test      loops: 1000000 avg: 1457671  usec

fix_size_alloc_test_4MB   loops: 1000000 avg: 62083711 usec
fix_size_alloc_test       loops: 1000000 avg: 449207   usec
full_fit_alloc_test       loops: 1000000 avg: 735985   usec
long_busy_list_alloc_test loops: 1000000 avg: 5176052  usec
random_size_alloc_test    loops: 1000000 avg: 2589252  usec
fix_align_alloc_test      loops: 1000000 avg: 1365009  usec

For example 4MB allocations illustrates ~30% gain, all the
rest is also better.

Link: https://lkml.kernel.org/r/20210516202056.2120-3-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:52 -07:00