With cache_trim_mode on, reclaim logic doesn't bother reclaiming anon
pages. However, it should be more careful to use the mode because it's
going to prevent anon pages from being reclaimed even if there are a huge
number of anon pages that are cold and should be reclaimed. Even worse,
that leads kswapd_failures to reach MAX_RECLAIM_RETRIES and stopping
kswapd from functioning until direct reclaim eventually works to resume
kswapd.
So kswapd needs to retry its scan priority loop with cache_trim_mode off
again if the mode doesn't work for reclaim.
The problematic behavior can be reproduced by:
CONFIG_NUMA_BALANCING enabled
sysctl_numa_balancing_mode set to NUMA_BALANCING_MEMORY_TIERING
numa node0 (8GB local memory, 16 CPUs)
numa node1 (8GB slow tier memory, no CPUs)
Sequence:
1) echo 3 > /proc/sys/vm/drop_caches
2) To emulate the system with full of cold memory in local DRAM, run
the following dummy program and never touch the region:
mmap(0, 8 * 1024 * 1024 * 1024, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE | MAP_POPULATE, -1, 0);
3) Run any memory intensive work e.g. XSBench.
4) Check if numa balancing is working e.i. promotion/demotion.
5) Iterate 1) ~ 4) until numa balancing stops.
With this, you could see that promotion/demotion are not working because
kswapd has stopped due to ->kswapd_failures >= MAX_RECLAIM_RETRIES.
Interesting vmstat delta's differences between before and after are like:
+-----------------------+-------------------------------+
| interesting vmstat | before | after |
+-----------------------+-------------------------------+
| nr_inactive_anon | 321935 | 1664772 |
| nr_active_anon | 1780700 | 437834 |
| nr_inactive_file | 30425 | 40882 |
| nr_active_file | 14961 | 3012 |
| pgpromote_success | 356 | 1293122 |
| pgpromote_candidate | 21953245 | 1824148 |
| pgactivate | 1844523 | 3311907 |
| pgdeactivate | 50634 | 1554069 |
| pgfault | 31100294 | 6518806 |
| pgdemote_kswapd | 30856 | 2230821 |
| pgscan_kswapd | 1861981 | 7667629 |
| pgscan_anon | 1822930 | 7610583 |
| pgscan_file | 39051 | 57046 |
| pgsteal_anon | 386 | 2192033 |
| pgsteal_file | 30470 | 38788 |
| pageoutrun | 30 | 412 |
| numa_hint_faults | 27418279 | 2875955 |
| numa_pages_migrated | 356 | 1293122 |
+-----------------------+-------------------------------+
Link: https://lkml.kernel.org/r/20240304082118.20499-1-byungchul@sk.com
Signed-off-by: Byungchul Park <byungchul@sk.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Users of UFFDIO_CONTINUE may reasonably assume that a write memory barrier
is included as part of UFFDIO_CONTINUE. That is, a user may believe that
all writes it has done to a page that it is now UFFDIO_CONTINUE'ing are
guaranteed to be visible to anyone subsequently reading the page through
the newly mapped virtual memory region.
Today, such a user happens to be correct. mmget_not_zero(), for example,
is called as part of UFFDIO_CONTINUE (and comes before any PTE updates),
and it implicitly gives us a write barrier.
To be resilient against future changes, include an explicit smp_wmb().
While we're at it, optimize the smp_wmb() that is already incidentally
present for the HugeTLB case.
Merely making a syscall does not generally imply the memory ordering
constraints that we need (including on x86).
Link: https://lkml.kernel.org/r/20240307010250.3847179-1-jthoughton@google.com
Signed-off-by: James Houghton <jthoughton@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
My recent change to put_pages_list() dereferences folio->lru.next after
returning the folio to the page allocator. Usually this is now on the pcp
list with other free folios, so we try to free an already-free folio.
This only happens with lists that have more than 15 entries, so it wasn't
immediately discovered. Revert to using list_for_each_safe() so we
dereference lru.next before disposing of the folio.
Link: https://lkml.kernel.org/r/20240306212749.1823380-1-willy@infradead.org
Fixes: 24835f899c ("mm: use free_unref_folios() in put_pages_list()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: "Borah, Chaitanya Kumar" <chaitanya.kumar.borah@intel.com>
Closes: https://lore.kernel.org/intel-gfx/SJ1PR11MB61292145F3B79DA58ADDDA63B9232@SJ1PR11MB6129.namprd11.prod.outlook.com/
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When freeing a large folio, we must remove it from the deferred split list
before we uncharge it as each memcg has its own deferred split list (with
associated lock) and removing a folio from the deferred split list while
holding the wrong lock will corrupt that list and cause various related
problems.
Link: https://lore.kernel.org/linux-mm/367a14f7-340e-4b29-90ae-bc3fcefdd5f4@arm.com/
Link: https://lkml.kernel.org/r/20240311191835.312162-1-willy@infradead.org
Fixes: f77171d241 (mm: allow non-hugetlb large folios to be batch processed)
Fixes: 29f3843026 (mm: free folios directly in move_folios_to_lru())
Fixes: bc2ff4cbc3 (mm: free folios in a batch in shrink_folio_list())
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Debugged-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This is the usual mix of updates for drivers that are used on (mostly
ARM) SoCs with no other top-level subsystem tree, including:
- The SCMI firmware subsystem gains support for version 3.2 of the
specification and updates to the notification code.
- Feature updates for Tegra and Qualcomm platforms for added
hardware support.
- A number of platforms get soc_device additions for identifying newly
added chips from Renesas, Qualcomm, Mediatek and Google.
- Trivial improvements for firmware and memory drivers amongst
others, in particular 'const' annotations throughout multiple
subsystems.
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Merge tag 'soc-drivers-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM SoC driver updates from Arnd Bergmann:
"This is the usual mix of updates for drivers that are used on (mostly
ARM) SoCs with no other top-level subsystem tree, including:
- The SCMI firmware subsystem gains support for version 3.2 of the
specification and updates to the notification code
- Feature updates for Tegra and Qualcomm platforms for added hardware
support
- A number of platforms get soc_device additions for identifying
newly added chips from Renesas, Qualcomm, Mediatek and Google
- Trivial improvements for firmware and memory drivers amongst
others, in particular 'const' annotations throughout multiple
subsystems"
* tag 'soc-drivers-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (96 commits)
tee: make tee_bus_type const
soc: qcom: aoss: add missing kerneldoc for qmp members
soc: qcom: geni-se: drop unused kerneldoc struct geni_wrapper param
soc: qcom: spm: fix building with CONFIG_REGULATOR=n
bus: ti-sysc: constify the struct device_type usage
memory: stm32-fmc2-ebi: keep power domain on
memory: stm32-fmc2-ebi: add MP25 RIF support
memory: stm32-fmc2-ebi: add MP25 support
memory: stm32-fmc2-ebi: check regmap_read return value
dt-bindings: memory-controller: st,stm32: add MP25 support
dt-bindings: bus: imx-weim: convert to YAML
watchdog: s3c2410_wdt: use exynos_get_pmu_regmap_by_phandle() for PMU regs
soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs
MAINTAINERS: Update SCMI entry with HWMON driver
MAINTAINERS: samsung: gs101: match patches touching Google Tensor SoC
memory: tegra: Fix indentation
memory: tegra: Add BPMP and ICC info for DLA clients
memory: tegra: Correct DLA client names
dt-bindings: memory: renesas,rpc-if: Document R-Car V4M support
firmware: arm_scmi: Update the supported clock protocol version
...
Merge a series from myself that replaces hardcoded SLAB_ cache flag
values with an enum, and explicitly deprecates the SLAB_MEM_SPREAD flag
that is a no-op sine SLAB removal.
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:
====================
pull-request: bpf-next 2024-03-11
We've added 59 non-merge commits during the last 9 day(s) which contain
a total of 88 files changed, 4181 insertions(+), 590 deletions(-).
The main changes are:
1) Enforce VM_IOREMAP flag and range in ioremap_page_range and introduce
VM_SPARSE kind and vm_area_[un]map_pages to be used in bpf_arena,
from Alexei.
2) Introduce bpf_arena which is sparse shared memory region between bpf
program and user space where structures inside the arena can have
pointers to other areas of the arena, and pointers work seamlessly for
both user-space programs and bpf programs, from Alexei and Andrii.
3) Introduce may_goto instruction that is a contract between the verifier
and the program. The verifier allows the program to loop assuming it's
behaving well, but reserves the right to terminate it, from Alexei.
4) Use IETF format for field definitions in the BPF standard
document, from Dave.
5) Extend struct_ops libbpf APIs to allow specify version suffixes for
stuct_ops map types, share the same BPF program between several map
definitions, and other improvements, from Eduard.
6) Enable struct_ops support for more than one page in trampolines,
from Kui-Feng.
7) Support kCFI + BPF on riscv64, from Puranjay.
8) Use bpf_prog_pack for arm64 bpf trampoline, from Puranjay.
9) Fix roundup_pow_of_two undefined behavior on 32-bit archs, from Toke.
====================
Link: https://lore.kernel.org/r/20240312003646.8692-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'vfs-6.9.uuid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs uuid updates from Christian Brauner:
"This adds two new ioctl()s for getting the filesystem uuid and
retrieving the sysfs path based on the path of a mounted filesystem.
Getting the filesystem uuid has been implemented in filesystem
specific code for a while it's now lifted as a generic ioctl"
* tag 'vfs-6.9.uuid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
xfs: add support for FS_IOC_GETFSSYSFSPATH
fs: add FS_IOC_GETFSSYSFSPATH
fat: Hook up sb->s_uuid
fs: FS_IOC_GETUUID
ovl: convert to super_set_uuid()
fs: super_set_uuid()
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Merge tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull block handle updates from Christian Brauner:
"Last cycle we changed opening of block devices, and opening a block
device would return a bdev_handle. This allowed us to implement
support for restricting and forbidding writes to mounted block
devices. It was accompanied by converting and adding helpers to
operate on bdev_handles instead of plain block devices.
That was already a good step forward but ultimately it isn't necessary
to have special purpose helpers for opening block devices internally
that return a bdev_handle.
Fundamentally, opening a block device internally should just be
equivalent to opening files. So now all internal opens of block
devices return files just as a userspace open would. Instead of
introducing a separate indirection into bdev_open_by_*() via struct
bdev_handle bdev_file_open_by_*() is made to just return a struct
file. Opening and closing a block device just becomes equivalent to
opening and closing a file.
This all works well because internally we already have a pseudo fs for
block devices and so opening block devices is simple. There's a few
places where we needed to be careful such as during boot when the
kernel is supposed to mount the rootfs directly without init doing it.
Here we need to take care to ensure that we flush out any asynchronous
file close. That's what we already do for opening, unpacking, and
closing the initramfs. So nothing new here.
The equivalence of opening and closing block devices to regular files
is a win in and of itself. But it also has various other advantages.
We can remove struct bdev_handle completely. Various low-level helpers
are now private to the block layer. Other helpers were simply
removable completely.
A follow-up series that is already reviewed build on this and makes it
possible to remove bdev->bd_inode and allows various clean ups of the
buffer head code as well. All places where we stashed a bdev_handle
now just stash a file and use simple accessors to get to the actual
block device which was already the case for bdev_handle"
* tag 'vfs-6.9.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (35 commits)
block: remove bdev_handle completely
block: don't rely on BLK_OPEN_RESTRICT_WRITES when yielding write access
bdev: remove bdev pointer from struct bdev_handle
bdev: make struct bdev_handle private to the block layer
bdev: make bdev_{release, open_by_dev}() private to block layer
bdev: remove bdev_open_by_path()
reiserfs: port block device access to file
ocfs2: port block device access to file
nfs: port block device access to files
jfs: port block device access to file
f2fs: port block device access to files
ext4: port block device access to file
erofs: port device access to file
btrfs: port device access to file
bcachefs: port block device access to file
target: port block device access to file
s390: port block device access to file
nvme: port block device access to file
block2mtd: port device access to files
bcache: port block device access to files
...
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Merge tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Misc features, cleanups, and fixes for vfs and individual filesystems.
Features:
- Support idmapped mounts for hugetlbfs.
- Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
where the passed offset is ignored if the file is O_APPEND. The new
flag allows a caller to enforce that the offset is honored to
conform to posix even if the file was opened in append mode.
- Move i_mmap_rwsem in struct address_space to avoid false sharing
between i_mmap and i_mmap_rwsem.
- Convert efs, qnx4, and coda to use the new mount api.
- Add a generic is_dot_dotdot() helper that's used by various
filesystems and the VFS code instead of open-coding it multiple
times.
- Recently we've added stable offsets which allows stable ordering
when iterating directories exported through NFS on e.g., tmpfs
filesystems. Originally an xarray was used for the offset map but
that caused slab fragmentation issues over time. This switches the
offset map to the maple tree which has a dense mode that handles
this scenario a lot better. Includes tests.
- Finally merge the case-insensitive improvement series Gabriel has
been working on for a long time. This cleanly propagates case
insensitive operations through ->s_d_op which in turn allows us to
remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
It also improves performance by trying a case-sensitive comparison
first and then fallback to case-insensitive lookup if that fails.
This also fixes a bug where overlayfs would be able to be mounted
over a case insensitive directory which would lead to all sort of
odd behaviors.
Cleanups:
- Make file_dentry() a simple accessor now that ->d_real() is
simplified because of the backing file work we did the last two
cycles.
- Use the dedicated file_mnt_idmap helper in ntfs3.
- Use smp_load_acquire/store_release() in the i_size_read/write
helpers and thus remove the hack to handle i_size reads in the
filemap code.
- The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
fs/
- It's no longer necessary to perform a second built-in initramfs
unpack call because we retain the contents of the previous
extraction. Remove it.
- Now that we have removed various allocators kfree_rcu() always
works with kmem caches and kmalloc(). So simplify various places
that only use an rcu callback in order to handle the kmem cache
case.
- Convert the pipe code to use a lockdep comparison function instead
of open-coding the nesting making lockdep validation easier.
- Move code into fs-writeback.c that was located in a header but can
be made static as it's only used in that one file.
- Rewrite the alignment checking iterators for iovec and bvec to be
easier to read, and also significantly more compact in terms of
generated code. This saves 270 bytes of text on x86-64 (with
clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
saves a bit of time for the same workload.
- Switch various places to use KMEM_CACHE instead of
kmem_cache_create().
- Use inode_set_ctime_to_ts() in inode_set_ctime_current()
- Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.
- Various smaller cleanups for eventfds.
Fixes:
- Fix various comments and typos, and unneeded initializations.
- Fix stack allocation hack for clang in the select code.
- Improve dump_mapping() debug code on a best-effort basis.
- Fix build errors in various selftests.
- Avoid wrap-around instrumentation in various places.
- Don't allow user namespaces without an idmapping to be used for
idmapped mounts.
- Fix sysv sb_read() call.
- Fix fallback implementation of the get_name() export operation"
* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
hugetlbfs: support idmapped mounts
qnx4: convert qnx4 to use the new mount api
fs: use inode_set_ctime_to_ts to set inode ctime to current time
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
efs: remove SLAB_MEM_SPREAD flag usage
jfs: remove SLAB_MEM_SPREAD flag usage
minix: remove SLAB_MEM_SPREAD flag usage
openpromfs: remove SLAB_MEM_SPREAD flag usage
proc: remove SLAB_MEM_SPREAD flag usage
qnx6: remove SLAB_MEM_SPREAD flag usage
...
ioremap_page_range() should be used for ranges within vmalloc range only.
The vmalloc ranges are allocated by get_vm_area(). PCI has "resource"
allocator that manages PCI_IOBASE, IO_SPACE_LIMIT address range, hence
introduce vmap_page_range() to be used exclusively to map pages
in PCI address space.
Fixes: 3e49a866c9 ("mm: Enforce VM_IOREMAP flag and range in ioremap_page_range.")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://lore.kernel.org/bpf/CANiq72ka4rir+RTN2FQoT=Vvprp_Ao-CvoYEkSNqtSY+RZj+AA@mail.gmail.com
issues or aren't considered to be needed in earlier kernel versions.
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Merge tag 'mm-hotfixes-stable-2024-03-07-16-17' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"6 hotfixes. 4 are cc:stable and the remainder pertain to post-6.7
issues or aren't considered to be needed in earlier kernel versions"
* tag 'mm-hotfixes-stable-2024-03-07-16-17' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
scripts/gdb/symbols: fix invalid escape sequence warning
mailmap: fix Kishon's email
init/Kconfig: lower GCC version check for -Warray-bounds
mm, mmap: fix vma_merge() case 7 with vma_ops->close
mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE fails
mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations
vmap/vmalloc APIs are used to map a set of pages into contiguous kernel
virtual space.
get_vm_area() with appropriate flag is used to request an area of kernel
address range. It's used for vmalloc, vmap, ioremap, xen use cases.
- vmalloc use case dominates the usage. Such vm areas have VM_ALLOC flag.
- the areas created by vmap() function should be tagged with VM_MAP.
- ioremap areas are tagged with VM_IOREMAP.
BPF would like to extend the vmap API to implement a lazily-populated
sparse, yet contiguous kernel virtual space. Introduce VM_SPARSE flag
and vm_area_map_pages(area, start_addr, count, pages) API to map a set
of pages within a given area.
It has the same sanity checks as vmap() does.
It also checks that get_vm_area() was created with VM_SPARSE flag
which identifies such areas in /proc/vmallocinfo
and returns zero pages on read through /proc/kcore.
The next commits will introduce bpf_arena which is a sparsely populated
shared memory region between bpf program and user space process. It will
map privately-managed pages into a sparse vm area with the following steps:
// request virtual memory region during bpf prog verification
area = get_vm_area(area_size, VM_SPARSE);
// on demand
vm_area_map_pages(area, kaddr, kend, pages);
vm_area_unmap_pages(area, kaddr, kend);
// after bpf program is detached and unloaded
free_vm_area(area);
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/bpf/20240305030516.41519-3-alexei.starovoitov@gmail.com
A major fault occurred when using mlockall(MCL_CURRENT | MCL_FUTURE) in
application, which leading to an unexpected issue[1].
This is caused by temporarily cleared PTE during a read+clear/modify/write
update of the PTE, eg, do_numa_page()/change_pte_range().
For the data segment of the user-mode program, the global variable area is
a private mapping. After the pagecache is loaded, the private anonymous
page is generated after the COW is triggered. Mlockall can lock COW pages
(anonymous pages), but the original file pages cannot be locked and may be
reclaimed. If the global variable (private anon page) is accessed when
vmf->pte is zeroed in numa fault, a file page fault will be triggered. At
this time, the original private file page may have been reclaimed. If the
page cache is not available at this time, a major fault will be triggered
and the file will be read, causing additional overhead.
This issue affects our traffic analysis service. The inbound traffic is
heavy. If a major fault occurs, the I/O schedule is triggered and the
original I/O is suspended. Generally, the I/O schedule is 0.7 ms. If
other applications are operating disks, the system needs to wait for more
than 10 ms. However, the inbound traffic is heavy and the NIC buffer is
small. As a result, packet loss occurs. But the traffic analysis service
can't tolerate packet loss.
Fix this by holding PTL and rechecking the PTE in filemap_fault() before
triggering a major fault. We do this check only if vma is VM_LOCKED to
reduce the performance impact in common scenarios.
In our product environment, there were 7 major faults every 12 hours.
After the patch is applied, no major fault have been triggered.
Testing file page read and write page fault performance in ext4 and
ramdisk using will-it-scale[2] on a x86 physical machine. The data is the
average change compared with the mainline after the patch is applied. The
test results are within the range of fluctuation. We do this check only
if vma is VM_LOCKED, therefore, no performance regressions is caused for
most common cases.
The test results are as follows:
processes processes_idle threads threads_idle
ext4 private file write: 0.22% 0.26% 1.21% -0.15%
ext4 private file read: 0.03% 1.00% 1.39% 0.34%
ext4 shared file write: -0.50% -0.02% -0.14% -0.02%
ramdisk private file write: 0.07% 0.02% 0.53% 0.04%
ramdisk private file read: 0.01% 1.60% -0.32% -0.02%
[1] https://lore.kernel.org/linux-mm/9e62fd9a-bee0-52bf-50a7-498fa17434ee@huawei.com/
[2] https://github.com/antonblanchard/will-it-scale/
Link: https://lkml.kernel.org/r/20240306083809.1236634-1-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Suggested-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
stackdepot only saves stack_records which size is greather than 0,
so we cannot possibly have empty stack_records.
Drop the check.
Link: https://lkml.kernel.org/r/20240306123217.29774-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: kernel test robot <oliver.sang@intel.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "page_owner: Fixup and cleanup".
This patchset consists of a fixup by an error that was reported by intel
robot, where it seems to be that by the time page_owner gets initialized,
stackdepot has already depleted its allocation space and returns
0-handles, turning that into null stack_records when trying to retrieve
the stack_record. I was not able to reproduce that from the config
because it booted fine for me, but when setting e.g: dummy_handle to 0
artificially, I could see the same error that was reported.
The second patch is a cleanup that can also lead to a compilation warning.
This patch (of 2):
Although the retrieval of the stack_records for {dummy,failure}_handle
happen when page_owner gets initialized, there seems to be some situations
where stackdepot space has been already depleted by then, so we get
0-handles which make stack_records being NULL for those cases.
Be careful to 1) only bump stack_records refcount and 2) only access
stack_record fields if we actually have a non-null stack_record between
hands.
Link: https://lkml.kernel.org/r/20240306123217.29774-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20240306123217.29774-2-osalvador@suse.de
Fixes: 4bedfb314b ("mm,page_owner: implement the tracking of the stacks count")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202403051032.e2f865a-lkp@intel.com
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There was previously a theoretical window where swapoff() could run and
teardown a swap_info_struct while a call to free_swap_and_cache() was
running in another thread. This could cause, amongst other bad
possibilities, swap_page_trans_huge_swapped() (called by
free_swap_and_cache()) to access the freed memory for swap_map.
This is a theoretical problem and I haven't been able to provoke it from a
test case. But there has been agreement based on code review that this is
possible (see link below).
Fix it by using get_swap_device()/put_swap_device(), which will stall
swapoff(). There was an extra check in _swap_info_get() to confirm that
the swap entry was not free. This isn't present in get_swap_device()
because it doesn't make sense in general due to the race between getting
the reference and swapoff. So I've added an equivalent check directly in
free_swap_and_cache().
Details of how to provoke one possible issue (thanks to David Hildenbrand
for deriving this):
--8<-----
__swap_entry_free() might be the last user and result in
"count == SWAP_HAS_CACHE".
swapoff->try_to_unuse() will stop as soon as soon as si->inuse_pages==0.
So the question is: could someone reclaim the folio and turn
si->inuse_pages==0, before we completed swap_page_trans_huge_swapped().
Imagine the following: 2 MiB folio in the swapcache. Only 2 subpages are
still references by swap entries.
Process 1 still references subpage 0 via swap entry.
Process 2 still references subpage 1 via swap entry.
Process 1 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
[then, preempted in the hypervisor etc.]
Process 2 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
Process 2 goes ahead, passes swap_page_trans_huge_swapped(), and calls
__try_to_reclaim_swap().
__try_to_reclaim_swap()->folio_free_swap()->delete_from_swap_cache()->
put_swap_folio()->free_swap_slot()->swapcache_free_entries()->
swap_entry_free()->swap_range_free()->
...
WRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);
What stops swapoff to succeed after process 2 reclaimed the swap cache
but before process1 finished its call to swap_page_trans_huge_swapped()?
--8<-----
Link: https://lkml.kernel.org/r/20240306140356.3974886-1-ryan.roberts@arm.com
Fixes: 7c00bafee8 ("mm/swap: free swap slots in batch")
Closes: https://lore.kernel.org/linux-mm/65a66eb9-41f8-4790-8db2-0c70ea15979f@redhat.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is an old trick in shadow_mapped() to use pXd_bad() to detect huge
pages. After commit 93fab1b22e ("mm: add generic p?d_leaf() macros") we
have a global API for huge mappings. Use that to replace the trick.
Link: https://lkml.kernel.org/r/20240305043750.93762-7-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit bf9b7df23c ("mm/zswap: global lru and shrinker shared by all
zswap_pools") introduced a new lock to protect zswap_next_shrink, instead
of reusing zswap_pools_lock.
But the problem is that it's initialized only when zswap enabled, which
causes bug if zswap_memcg_offline_cleanup() called without zswap enabled.
Fix it by using DEFINE_SPINLOCK() to statically initialize them and define
them as multiple static variables to keep in consistent with the existing
global variables in zswap.
Link: https://lkml.kernel.org/r/20240305075345.1493214-1-chengming.zhou@linux.dev
Fixes: bf9b7df23c ("mm/zswap: global lru and shrinker shared by all zswap_pools")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202403051008.a8cf8a94-lkp@intel.com
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The rounddown_pow_of_two(0) is undefined, so val = 0 is not allowed in the
fault_around_bytes_set(), and leads to shift-out-of-bounds,
UBSAN: shift-out-of-bounds in include/linux/log2.h:67:13
shift exponent 4294967295 is too large for 64-bit type 'long unsigned int'
CPU: 7 PID: 107 Comm: sh Not tainted 6.8.0-rc6-next-20240301 #294
Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
Call trace:
dump_backtrace+0x94/0xec
show_stack+0x18/0x24
dump_stack_lvl+0x78/0x90
dump_stack+0x18/0x24
ubsan_epilogue+0x10/0x44
__ubsan_handle_shift_out_of_bounds+0x98/0x134
fault_around_bytes_set+0xa4/0xb0
simple_attr_write_xsigned.isra.0+0xe4/0x1ac
simple_attr_write+0x18/0x24
debugfs_attr_write+0x4c/0x98
vfs_write+0xd0/0x4b0
ksys_write+0x6c/0xfc
__arm64_sys_write+0x1c/0x28
invoke_syscall+0x44/0x104
el0_svc_common.constprop.0+0x40/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x34/0xdc
el0t_64_sync_handler+0xc0/0xc4
el0t_64_sync+0x190/0x194
---[ end trace ]---
Fix it by setting the minimum val to PAGE_SIZE.
Link: https://lkml.kernel.org/r/20240302064312.2358924-1-wangkefeng.wang@huawei.com
Fixes: 53d36a56d8 ("mm: prefer fault_around_pages to fault_around_bytes")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reported-by: Yue Sun <samsun1006219@gmail.com>
Closes: https://lore.kernel.org/all/CAEkJfYPim6DQqW1GqCiHLdh2-eweqk1fGyXqs3JM+8e1qGge8w@mail.gmail.com/
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fixes Coccinelle/coccicheck warning reported by do_div.cocci.
Compared to do_div(), div64_ul() does not implicitly cast the divisor and
does not unnecessarily calculate the remainder.
Link: https://lkml.kernel.org/r/20240228224911.1164-2-thorsten.blum@toblux.com
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We actually add folios to the pagelist already, but then work with them as
pages. Removes a call to compound_head() in PageKsm() and removes a
reference to page->index.
Link: https://lkml.kernel.org/r/20240229153015.1996829-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Gregory Price <gregory.price@memverge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
madvise, mprotect and some others might need folio_pte_batch to check if a
range of PTEs are completely mapped to a large folio with contiguous
physical addresses. Let's make it available in mm/internal.h.
While at it, add proper kernel doc and sanity-check more input parameters
using two additional VM_WARN_ON_FOLIO().
[21cnbao@gmail.com: build fix]
Link: https://lkml.kernel.org/r/CAGsJ_4wWzG-37D82vqP_zt+Fcbz+URVe5oXLBc4M5wbN8A_gpQ@mail.gmail.com
[david@redhat.com: improve the doc for the exported func]
Link: https://lkml.kernel.org/r/20240227104201.337988-1-21cnbao@gmail.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Constify the flag tests that aren't automatically generated and the tests
that look like flag tests but are more complicated.
Link: https://lkml.kernel.org/r/20240227192337.757313-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now that __dump_page() takes a const argument, we can make dump_page()
take a const struct page too.
Link: https://lkml.kernel.org/r/20240227192337.757313-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Optimizing the initialization speed of 1G huge pages through
parallelization.
1G hugetlbs are allocated from bootmem, a process that is already very
fast and does not currently require optimization. Therefore, we focus on
parallelizing only the initialization phase in `gather_bootmem_prealloc`.
Here are some test results:
test case no patch(ms) patched(ms) saved
------------------- -------------- ------------- --------
256c2T(4 node) 1G 4745 2024 57.34%
128c1T(2 node) 1G 3358 1712 49.02%
12T 1G 77000 18300 76.23%
[akpm@linux-foundation.org: s/initialied/initialized/, per Alexey]
Link: https://lkml.kernel.org/r/20240222140422.393911-9-gang.li@linux.dev
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
By distributing both the allocation and the initialization tasks across
multiple threads, the initialization of 2M hugetlb will be faster, thereby
improving the boot speed.
Here are some test results:
test case no patch(ms) patched(ms) saved
------------------- -------------- ------------- --------
256c2T(4 node) 2M 3336 1051 68.52%
128c1T(2 node) 2M 1943 716 63.15%
Link: https://lkml.kernel.org/r/20240222140422.393911-8-gang.li@linux.dev
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
different nodes Date: Thu, 22 Feb 2024 22:04:17 +0800
When a group of tasks that access different nodes are scheduled on the
same node, they may encounter bandwidth bottlenecks and access latency.
Thus, numa_aware flag is introduced here, allowing tasks to be distributed
across different nodes to fully utilize the advantage of multi-node
systems.
Link: https://lkml.kernel.org/r/20240222140422.393911-5-gang.li@linux.dev
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With parallelization of hugetlb allocation across different threads, each
thread works on a differnet node to allocate pages from, instead of all
allocating from a common node h->next_nid_to_alloc. To address this, it's
necessary to assign a separate next_nid_to_alloc for each thread.
Consequently, the hstate_next_node_to_alloc and
for_each_node_mask_to_alloc have been modified to directly accept a
*next_nid_to_alloc parameter, ensuring thread-specific allocation and
avoiding concurrent access issues.
Link: https://lkml.kernel.org/r/20240222140422.393911-4-gang.li@linux.dev
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1G and 2M huge pages have different allocation and initialization logic,
which leads to subtle differences in parallelization. Therefore, it is
appropriate to split hugetlb_hstate_alloc_pages into gigantic and
non-gigantic.
This patch has no functional changes.
Link: https://lkml.kernel.org/r/20240222140422.393911-3-gang.li@linux.dev
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "hugetlb: parallelize hugetlb page init on boot", v6.
Introduction
------------
Hugetlb initialization during boot takes up a considerable amount of time.
For instance, on a 2TB system, initializing 1,800 1GB huge pages takes
1-2 seconds out of 10 seconds. Initializing 11,776 1GB pages on a 12TB
Intel host takes more than 1 minute[1]. This is a noteworthy figure.
Inspired by [2] and [3], hugetlb initialization can also be accelerated
through parallelization. Kernel already has infrastructure like
padata_do_multithreaded, this patch uses it to achieve effective results
by minimal modifications.
[1] https://lore.kernel.org/all/783f8bac-55b8-5b95-eb6a-11a583675000@google.com/
[2] https://lore.kernel.org/all/20200527173608.2885243-1-daniel.m.jordan@oracle.com/
[3] https://lore.kernel.org/all/20230906112605.2286994-1-usama.arif@bytedance.com/
[4] https://lore.kernel.org/all/76becfc1-e609-e3e8-2966-4053143170b6@google.com/
max_threads
-----------
This patch use `padata_do_multithreaded` like this:
```
job.max_threads = num_node_state(N_MEMORY) * multiplier;
padata_do_multithreaded(&job);
```
To fully utilize the CPU, the number of parallel threads needs to be
carefully considered. `max_threads = num_node_state(N_MEMORY)` does not
fully utilize the CPU, so we need to multiply it by a multiplier.
Tests below indicate that a multiplier of 2 significantly improves
performance, and although larger values also provide improvements, the
gains are marginal.
multiplier 1 2 3 4 5
------------ ------- ------- ------- ------- -------
256G 2node 358ms 215ms 157ms 134ms 126ms
2T 4node 979ms 679ms 543ms 489ms 481ms
50G 2node 71ms 44ms 37ms 30ms 31ms
Therefore, choosing 2 as the multiplier strikes a good balance between
enhancing parallel processing capabilities and maintaining efficient
resource management.
Test result
-----------
test case no patch(ms) patched(ms) saved
------------------- -------------- ------------- --------
256c2T(4 node) 1G 4745 2024 57.34%
128c1T(2 node) 1G 3358 1712 49.02%
12T 1G 77000 18300 76.23%
256c2T(4 node) 2M 3336 1051 68.52%
128c1T(2 node) 2M 1943 716 63.15%
This patch (of 8):
The readability of `hugetlb_hstate_alloc_pages` is poor. By cleaning the
code, its readability can be improved, facilitating future modifications.
This patch extracts two functions to reduce the complexity of
`hugetlb_hstate_alloc_pages` and has no functional changes.
- hugetlb_hstate_alloc_pages_node_specific() to handle iterates through
each online node and performs allocation if necessary.
- hugetlb_hstate_alloc_pages_report() report error during allocation.
And the value of h->max_huge_pages is updated accordingly.
Link: https://lkml.kernel.org/r/20240222140422.393911-1-gang.li@linux.dev
Link: https://lkml.kernel.org/r/20240222140422.393911-2-gang.li@linux.dev
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Tested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There are various users of get_vm_area() + ioremap_page_range() APIs.
Enforce that get_vm_area() was requested as VM_IOREMAP type and range
passed to ioremap_page_range() matches created vm_area to avoid
accidentally ioremap-ing into wrong address range.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/bpf/20240305030516.41519-2-alexei.starovoitov@gmail.com
When draining a page_frag_cache, most user are doing
the similar steps, so introduce an API to avoid code
duplication.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently there seems to be three page frag implementations
which all try to allocate order 3 page, if that fails, it
then fail back to allocate order 0 page, and each of them
all allow order 3 page allocation to fail under certain
condition by using specific gfp bits.
The gfp bits for order 3 page allocation are different
between different implementation, __GFP_NOMEMALLOC is
or'd to forbid access to emergency reserves memory for
__page_frag_cache_refill(), but it is not or'd in other
implementions, __GFP_DIRECT_RECLAIM is masked off to avoid
direct reclaim in vhost_net_page_frag_refill(), but it is
not masked off in __page_frag_cache_refill().
This patch unifies the gfp bits used between different
implementions by or'ing __GFP_NOMEMALLOC and masking off
__GFP_DIRECT_RECLAIM for order 3 page allocation to avoid
possible pressure for mm.
Leave the gfp unifying for page frag implementation in sock.c
for now as suggested by Paolo Abeni.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
CC: Alexander Duyck <alexander.duyck@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
napi_alloc_frag_align() and netdev_alloc_frag_align() accept
align as an argument, and they are thin wrappers around the
__napi_alloc_frag_align() and __netdev_alloc_frag_align() APIs
doing the alignment checking and align mask conversion, in order
to call page_frag_alloc_align() directly. The intention here is
to keep the alignment checking and the alignmask conversion in
in-line wrapper to avoid those kind of operations during execution
time since it can usually be handled during compile time.
We are going to use page_frag_alloc_align() in vhost_net.c, it
need the same kind of alignment checking and alignmask conversion,
so split up page_frag_alloc_align into an inline wrapper doing the
above operation, and add __page_frag_alloc_align() which is passed
with the align mask the original function expected as suggested by
Alexander.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
CC: Alexander Duyck <alexander.duyck@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The PARTIAL_NODE slab_state has gone with SLAB removed, so just
remove it.
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
We will save allocated tag in the object header to indicate that it's
allocated.
handle |= OBJ_ALLOCATED_TAG;
So the object header needs to reserve LSB for this tag bit.
But the handle itself doesn't need to reserve LSB to save tag, since it's
only used to find the position of object, by (pfn + obj_idx). So remove
LSB reserve from handle, one more bit can be used as obj_idx.
Link: https://lkml.kernel.org/r/20240228023854.3511239-1-chengming.zhou@linux.dev
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
do_numa_page() is reading from the same page table entry, twice, while
holding the page table lock: once while checking that the pte hasn't
changed, and again in order to modify the pte.
Instead, just read the pte once, and save it in the same old_pte variable
that already exists. This has no effect on behavior, other than to
provide a tiny potential improvement to performance, by avoiding the
redundant memory read (which the compiler cannot elide, due to
READ_ONCE()).
Also improve the associated comments nearby.
Link: https://lkml.kernel.org/r/20240228034151.459370-1-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
alloc_contig_migrate_range has every information to be able to understand
big contiguous allocation latency. For example, how many pages are
migrated, how many times they were needed to unmap from page tables.
This patch adds the trace event to collect the allocation statistics. In
the field, it was quite useful to understand CMA allocation latency.
[akpm@linux-foundation.org: a/trace_mm_alloc_config_migrate_range_info_enabled/trace_mm_alloc_contig_migrate_range_info_enabled]
Link: https://lkml.kernel.org/r/20240228051127.2859472-1-richardycc@google.com
Signed-off-by: Richard Chang <richardycc@google.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org.
Cc: Martin Liu <liumartin@google.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We already have a folio; use it instead of the head page where reasonable.
Saves a couple of calls to compound_head() and elimimnates a few
references to page->mapping.
Link: https://lkml.kernel.org/r/20240228164326.1355045-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All but one caller already has a folio, so convert
free_page_and_swap_cache() to have a folio and remove the call to
page_folio().
Link: https://lkml.kernel.org/r/20240227174254.710559-19-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
These pages are all chained together through the lru list, so we know
they're folios. Use the folio APIs to save three hidden calls to
compound_head().
Link: https://lkml.kernel.org/r/20240227174254.710559-18-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Process the pages in batch-sized quantities instead of all-at-once.
Link: https://lkml.kernel.org/r/20240227174254.710559-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All callers now use free_unref_folios() so we can delete this function.
Link: https://lkml.kernel.org/r/20240227174254.710559-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All users have been converted to mem_cgroup_uncharge_folios() so we can
remove this API.
Link: https://lkml.kernel.org/r/20240227174254.710559-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The few folios which can't be moved to the LRU list (because their
refcount dropped to zero) used to be returned to the caller to dispose of.
Make this simpler to call by freeing the folios directly through
free_unref_folios().
Link: https://lkml.kernel.org/r/20240227174254.710559-13-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use free_unref_page_batch() to free the folios. This may increase the
number of IPIs from calling try_to_unmap_flush() more often, but that's
going to be very workload-dependent. It may even reduce the number of
IPIs as we now batch-free large folios instead of freeing them one at a
time.
Link: https://lkml.kernel.org/r/20240227174254.710559-12-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hugetlb folios still get special treatment, but normal large folios can
now be freed by free_unref_folios(). This should have a reasonable
performance impact, TBD.
Link: https://lkml.kernel.org/r/20240227174254.710559-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Call folio_undo_large_rmappable() if needed. free_unref_page_prepare()
destroys the ability to call folio_order(), so stash the order in
folio->private for the benefit of the second loop.
Link: https://lkml.kernel.org/r/20240227174254.710559-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pass a pointer to the lruvec so we can take advantage of the
folio_lruvec_relock_irqsave(). Adjust the calling convention of
folio_lruvec_relock_irqsave() to suit and add a page_cache_release()
wrapper.
Link: https://lkml.kernel.org/r/20240227174254.710559-9-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Break up the list of folios into batches here so that the folios are more
likely to be cache hot when doing the rest of the processing.
Link: https://lkml.kernel.org/r/20240227174254.710559-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Instead of putting the interesting folios on a list, delete the
uninteresting one from the folio_batch.
Link: https://lkml.kernel.org/r/20240227174254.710559-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Almost identical to mem_cgroup_uncharge_list(), except it takes a
folio_batch instead of a list_head.
Link: https://lkml.kernel.org/r/20240227174254.710559-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There's no need to indirect through release_pages() and iterate over this
batch of folios an extra time; we can just use the batch that we have.
Link: https://lkml.kernel.org/r/20240227174254.710559-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Iterate over a folio_batch rather than a linked list. This is easier for
the CPU to prefetch and has a batch count naturally built in so we don't
need to track it. Again, this lowers the maximum lock hold time from
32 folios to 15, but I do not expect this to have a significant effect.
Link: https://lkml.kernel.org/r/20240227174254.710559-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Most of its callees are not yet ready to accept a folio, but we know all
of the pages passed in are actually folios because they're linked through
->lru.
Link: https://lkml.kernel.org/r/20240227174254.710559-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Rearrange batched folio freeing", v3.
Other than the obvious "remove calls to compound_head" changes, the
fundamental belief here is that iterating a linked list is much slower
than iterating an array (5-15x slower in my testing). There's also an
associated belief that since we iterate the batch of folios three times,
we do better when the array is small (ie 15 entries) than we do with a
batch that is hundreds of entries long, which only gives us the
opportunity for the first pages to fall out of cache by the time we get to
the end.
It is possible we should increase the size of folio_batch. Hopefully the
bots let us know if this introduces any performance regressions.
This patch (of 3):
By making release_pages() call folios_put(), we can get rid of the calls
to compound_head() for the callers that already know they have folios. We
can also get rid of the lock_batch tracking as we know the size of the
batch is limited by folio_batch. This does reduce the maximum number of
pages for which the lruvec lock is held, from SWAP_CLUSTER_MAX (32) to
PAGEVEC_SIZE (15). I do not expect this to make a significant difference,
but if it does, we can increase PAGEVEC_SIZE to 31.
Link: https://lkml.kernel.org/r/20240227174254.710559-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240227174254.710559-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously, we removed the mm from mm_slot and dropped mm_count
if the MMF_THP_DISABLE flag was set. However, we didn't re-add
the mm back after clearing the MMF_THP_DISABLE flag. Additionally,
We add a check for the MMF_THP_DISABLE flag in hugepage_vma_revalidate().
Link: https://lkml.kernel.org/r/20240227035135.54593-1-ioworker0@gmail.com
Fixes: 879c6000e1 ("mm/khugepaged: bypassing unnecessary scans with MMF_DISABLE_THP check")
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Suggested-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: remove total_mapcount()", v2.
Let's remove the remaining user from mm/memfd.c so we can get rid of
total_mapcount().
This patch (of 2):
Both functions are the remaining users of total_mapcount(). Let's get rid
of the calls by converting the code to folios.
As it turns out, the code is unnecessarily complicated, especially:
1) We can query the number of pagecache references for a folio simply via
folio_nr_pages(). This will handle other folio sizes in the future
correctly.
2) The xas_set(xas, page->index + cache_count) call to increment the
iterator for large folios is not required. Remove it.
Further, simplify the XA_CHECK_SCHED check, counting each entry exactly
once.
Memfd pages can be swapped out when using shmem; leave xa_is_value()
checks in place.
Link: https://lkml.kernel.org/r/20240226141324.278526-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240226141324.278526-2-david@redhat.com
Co-developed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is used to test split_huge_page_to_list_to_order for pagecache THPs.
Also add test cases for split_huge_page_to_list_to_order via both debugfs.
[ziy@nvidia.com: fix issue discovered with NFS]
Link: https://lkml.kernel.org/r/262E4DAA-4A78-4328-B745-1355AE356A07@nvidia.com
Link: https://lkml.kernel.org/r/20240226205534.1603748-9-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Tested-by: Aishwarya TCV <aishwarya.tcv@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Aishwarya TCV <aishwarya.tcv@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
To split a THP to any lower order pages, we need to reform THPs on
subpages at given order and add page refcount based on the new page order.
Also we need to reinitialize page_deferred_list after removing the page
from the split_queue, otherwise a subsequent split will see list
corruption when checking the page_deferred_list again.
Note: Anonymous order-1 folio is not supported because _deferred_list,
which is used by partially mapped folios, is stored in subpage 2 and an
order-1 folio only has subpage 0 and 1. File-backed order-1 folios are
fine, since they do not use _deferred_list.
[ziy@nvidia.com: fixup per discussion with Ryan]
Link: https://lkml.kernel.org/r/494F48CD-1F0F-4CAD-884E-6D48F40AF990@nvidia.com
Link: https://lkml.kernel.org/r/20240226205534.1603748-8-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It adds a new_order parameter to set new page order in page owner. It
prepares for upcoming changes to support split huge page to any lower
order.
Link: https://lkml.kernel.org/r/20240226205534.1603748-7-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It sets memcg information for the pages after the split. A new parameter
new_order is added to tell the order of subpages in the new page, always 0
for now. It prepares for upcoming changes to support split huge page to
any lower order.
Link: https://lkml.kernel.org/r/20240226205534.1603748-6-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We do not have non power of two pages, using nr is error prone if nr is
not power-of-two. Use page order instead.
Link: https://lkml.kernel.org/r/20240226205534.1603748-5-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We do not have non power of two pages, using nr is error prone if nr is
not power-of-two. Use page order instead.
Link: https://lkml.kernel.org/r/20240226205534.1603748-4-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Folios of order 1 have no space to store the deferred list. This is not a
problem for the page cache as file-backed folios are never placed on the
deferred list. All we need to do is prevent the core MM from touching the
deferred list for order 1 folios and remove the code which prevented us
from allocating order 1 folios.
Link: https://lore.kernel.org/linux-mm/90344ea7-4eec-47ee-5996-0c22f42d6a6a@google.com/
Link: https://lkml.kernel.org/r/20240226205534.1603748-3-zi.yan@sent.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Split a folio to any lower order folios", v5.
File folio supports any order and multi-size THP is upstreamed[1], so both
file and anonymous folios can be >0 order. Currently, split_huge_page()
only splits a huge page to order-0 pages, but splitting to orders higher
than 0 might better utilize large folios, if done properly. In addition,
Large Block Sizes in XFS support would benefit from it during truncate[2].
This patchset adds support for splitting a large folio to any lower order
folios.
In addition to this implementation of split_huge_page_to_list_to_order(),
a possible optimization could be splitting a large folio to arbitrary
smaller folios instead of a single order. As both Hugh and Ryan pointed
out [3,5] that split to a single order might not be optimal, an order-9
folio might be better split into 1 order-8, 1 order-7, ..., 1 order-1, and
2 order-0 folios, depending on subsequent folio operations. Leave this as
future work.
[1] https://lore.kernel.org/all/20231207161211.2374093-1-ryan.roberts@arm.com/
[2] https://lore.kernel.org/linux-mm/20240226094936.2677493-1-kernel@pankajraghav.com/
[3] https://lore.kernel.org/linux-mm/9dd96da-efa2-5123-20d4-4992136ef3ad@google.com/
[4] https://lore.kernel.org/linux-mm/cbb1d6a0-66dd-47d0-8733-f836fe050374@arm.com/
[5] https://lore.kernel.org/linux-mm/20240213215520.1048625-1-zi.yan@sent.com/
This patch (of 8):
As multi-size THP support is added, not all THPs are PMD-mapped, thus
during a huge page split, there is no need to always split PMD mapping in
unmap_folio(). Make it conditional.
Link: https://lkml.kernel.org/r/20240226205534.1603748-1-zi.yan@sent.com
Link: https://lkml.kernel.org/r/20240226205534.1603748-2-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
While doing MADV_PAGEOUT, the current code will clear PTE young so that
vmscan won't read young flags to allow the reclamation of madvised folios
to go ahead. It seems we can do it by directly ignoring references, thus
we can remove tlb flush in madvise and rmap overhead in vmscan.
Regarding the side effect, in the original code, if a parallel thread runs
side by side to access the madvised memory with the thread doing madvise,
folios will get a chance to be re-activated by vmscan (though the time gap
is actually quite small since checking PTEs is done immediately after
clearing PTEs young). But with this patch, they will still be reclaimed.
But this behaviour doing PAGEOUT and doing access at the same time is
quite silly like DoS. So probably, we don't need to care. Or ignoring
the new access during the quite small time gap is even better.
For DAMON's DAMOS_PAGEOUT based on physical address region, we still keep
its behaviour as is since a physical address might be mapped by multiple
processes. MADV_PAGEOUT based on virtual address is actually much more
aggressive on reclamation. To untouch paddr's DAMOS_PAGEOUT, we simply
pass ignore_references as false in reclaim_pages().
A microbench as below has shown 6% decrement on the latency of
MADV_PAGEOUT,
#define PGSIZE 4096
main()
{
int i;
#define SIZE 512*1024*1024
volatile long *p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
for (i = 0; i < SIZE/sizeof(long); i += PGSIZE / sizeof(long))
p[i] = 0x11;
madvise(p, SIZE, MADV_PAGEOUT);
}
w/o patch w/ patch
root@10:~# time ./a.out root@10:~# time ./a.out
real 0m49.634s real 0m46.334s
user 0m0.637s user 0m0.648s
sys 0m47.434s sys 0m44.265s
Link: https://lkml.kernel.org/r/20240226005739.24350-1-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Address the additional feedback since 4e76c8cc33 kasan: add atomic tests
(""kasan: add atomic tests") by removing an explicit cast and fixing the
size as well as the check of the allocation of `a2`.
Link: https://lkml.kernel.org/r/20240224105414.211995-1-paul.heidekrueger@tum.de
Link: https://lore.kernel.org/all/20240131210041.686657-1-paul.heidekrueger@tum.de/T/#u
Fixes: 4e76c8cc33 ("kasan: add atomic tests")
Signed-off-by: Paul Heidekrüger <paul.heidekrueger@tum.de>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=214055
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The current implementation of the mark_victim tracepoint provides only the
process ID (pid) of the victim process. This limitation poses challenges
for userspace tools requiring real-time OOM analysis and intervention.
Although this information is available from the kernel logs, it’s not
the appropriate format to provide OOM notifications. In Android, BPF
programs are used with the mark_victim trace events to notify userspace of
an OOM kill. For consistency, update the trace event to include the same
information about the OOMed victim as the kernel logs.
- UID
In Android each installed application has a unique UID. Including
the `uid` assists in correlating OOM events with specific apps.
- Process Name (comm)
Enables identification of the affected process.
- OOM Score
Will allow userspace to get additional insight of the relative kill
priority of the OOM victim. In Android, the oom_score_adj is used to
categorize app state (foreground, background, etc.), which aids in
analyzing user-perceptible impacts of OOM events [1].
- Total VM, RSS Stats, and pgtables
Amount of memory used by the victim that will, potentially, be freed up
by killing it.
[1] 246dc8fc95:frameworks/base/services/core/java/com/android/server/am/ProcessList.java;l=188-283
Signed-off-by: Carlos Galo <carlosgalo@google.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Hugetlb can now safely handle faults under the VMA lock, so allow it to do
so.
This patch may cause ltp hugemmap10 to "fail". Hugemmap10 tests hugetlb
counters, and expects the counters to remain unchanged on failure to
handle a fault.
In hugetlb_no_page(), vmf_anon_prepare() may bailout with no anon_vma
under the VMA lock after allocating a folio for the hugepage. In
free_huge_folio(), this folio is completely freed on bailout iff there is
a surplus of hugetlb pages. This will remove a folio off the freelist and
decrement the number of hugepages while ltp expects these counters to
remain unchanged on failure.
Originally this could only happen due to OOM failures, but now it may also
occur after we allocate a hugetlb folio without a suitable anon_vma under
the VMA lock. This should only happen for the first freshly allocated
hugepage in this vma.
Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
hugetlb_no_page() and hugetlb_wp() call anon_vma_prepare(). In
preparation for hugetlb to safely handle faults under the VMA lock, use
vmf_anon_prepare() here instead.
Additionally, passing hugetlb_wp() the vm_fault struct from
hugetlb_fault() works toward cleaning up the hugetlb code and function
stack.
Link: https://lkml.kernel.org/r/20240221234732.187629-5-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now that hugetlb_fault() has a struct vm_fault, have
hugetlb_handle_userfault() use it instead of creating one of its own.
This lets us reduce the number of arguments passed to
hugetlb_handle_userfault() from 7 to 3, cleaning up the code and stack.
Link: https://lkml.kernel.org/r/20240221234732.187629-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
hugetlb_fault() currently defines a vm_fault to pass to the generic
handle_userfault() function. We can move this definition to the top of
hugetlb_fault() so that it can be used throughout the rest of the hugetlb
fault path.
This will help cleanup a number of excess variables and function arguments
throughout the stack. Also, since vm_fault already has space to store the
page offset, use that instead and get rid of idx.
Link: https://lkml.kernel.org/r/20240221234732.187629-3-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Handle hugetlb faults under the VMA lock", v2.
It is generally safe to handle hugetlb faults under the VMA lock. The
only time this is unsafe is when no anon_vma has been allocated to this
vma yet, so we can use vmf_anon_prepare() instead of anon_vma_prepare() to
bailout if necessary. This should only happen for the first hugetlb page
in the vma.
Additionally, this patchset begins to use struct vm_fault within
hugetlb_fault(). This works towards cleaning up hugetlb code, and should
significantly reduce the number of arguments passed to functions.
The last patch in this series may cause ltp hugemmap10 to "fail". This is
because vmf_anon_prepare() may bailout with no anon_vma under the VMA lock
after allocating a folio for the hugepage. In free_huge_folio(), this
folio is completely freed on bailout iff there is a surplus of hugetlb
pages. This will remove a folio off the freelist and decrement the number
of hugepages while ltp expects these counters to remain unchanged on
failure. The rest of the ltp testcases pass.
This patch (of 2):
In order to handle hugetlb faults under the VMA lock, hugetlb can use
vmf_anon_prepare() to ensure we can safely prepare an anon_vma. Change it
to be a non-static function so it can be used within hugetlb as well.
Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20240221234732.187629-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Make check_new_page() return bool like check_new_pages()
Link: https://lkml.kernel.org/r/20240222091932.54799-1-gehao@kylinos.cn
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 44b414c871 ("mm/util.c: add warning if
__vm_enough_memory fails") adds debug information which gives the process
id and executable name should __vm_enough_memory() fail. Adding the
number of pages to the failure message would benefit application
developers and system administrators in debugging overambitious memory
requests by providing a point of reference to the amount of memory causing
__vm_enough_memory() to fail.
1. Set appropriate kernel tunable to reach code path for failure
message:
# echo 2 > /proc/sys/vm/overcommit_memory
2. Test program to generate failure - requests 1 gibibyte per
iteration:
#include <stdlib.h>
#include <stdio.h>
int main(int argc, char **argv) {
for(;;) {
if(malloc(1<<30) == NULL)
break;
printf("allocated 1 GiB\n");
}
return 0;
}
3. Output:
Before:
__vm_enough_memory: pid: 1218, comm: a.out, not enough memory
for the allocation
After:
__vm_enough_memory: pid: 1137, comm: a.out, bytes: 1073741824,
not enough memory for the allocation
Link: https://lkml.kernel.org/r/20240222194617.1255-1-mcassell411@gmail.com
Signed-off-by: Matthew Cassell <mcassell411@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
All zswap entries will take a reference of zswap_pool when zswap_store(),
and drop it when free. Change it to use the percpu_ref is better for
scalability performance.
Although percpu_ref use a bit more memory which should be ok for our use
case, since we almost have only one zswap_pool to be using. The
performance gain is for zswap_store/load hotpath.
Testing kernel build (32 threads) in tmpfs with memory.max=2GB. (zswap
shrinker and writeback enabled with one 50GB swapfile, on a 128 CPUs
x86-64 machine, below is the average of 5 runs)
mm-unstable zswap-global-lru
real 63.20 63.12
user 1061.75 1062.95
sys 268.74 264.44
[chengming.zhou@linux.dev: fix zswap_pools_lock usages after changing to percpu_ref]
Link: https://lkml.kernel.org/r/20240228154954.3028626-1-chengming.zhou@linux.dev
Link: https://lkml.kernel.org/r/20240210-zswap-global-lru-v3-2-200495333595@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/zswap: optimize for dynamic zswap_pools", v3.
Dynamic pool creation has been supported for a long time, which maybe not
used so much in practice. But with the per-memcg lru merged, the current
structure of zswap_pool's lru and shrinker become less optimal.
In the current structure, each zswap_pool has its own lru, shrinker and
shrink_work, but only the latest zswap_pool will be the current used.
1. When memory has pressure, all shrinkers of zswap_pools will try to
shrink its lru list, there is no order between them.
2. When zswap limit hit, only the last zswap_pool's shrink_work will
try to shrink its own lru, which is inefficient.
A more natural way is to have a global zswap lru shared between all
zswap_pools, and so is the shrinker. The code becomes much simpler too.
Another optimization is changing zswap_pool kref to percpu_ref, which will
be taken reference by every zswap entry. So the scalability is better.
Testing kernel build (32 threads) in tmpfs with memory.max=2GB. (zswap
shrinker and writeback enabled with one 50GB swapfile, on a 128 CPUs
x86-64 machine, below is the average of 5 runs)
mm-unstable zswap-global-lru
real 63.20 63.12
user 1061.75 1062.95
sys 268.74 264.44
This patch (of 3):
Dynamic zswap_pool creation may create/reuse to have multiple zswap_pools
in a list, only the first will be current used.
Each zswap_pool has its own lru and shrinker, which is not necessary and
has its problem:
1. When memory has pressure, all shrinker of zswap_pools will
try to shrink its own lru, there is no order between them.
2. When zswap limit hit, only the last zswap_pool's shrink_work
will try to shrink its lru list. The rationale here was to
try and empty the old pool first so that we can completely
drop it. However, since we only support exclusive loads now,
the LRU ordering should be entirely decided by the order of
stores, so the oldest entries on the LRU will naturally be
from the oldest pool.
Anyway, having a global lru and shrinker shared by all zswap_pools is
better and efficient.
Link: https://lkml.kernel.org/r/20240210-zswap-global-lru-v3-0-200495333595@bytedance.com
Link: https://lkml.kernel.org/r/20240210-zswap-global-lru-v3-1-200495333595@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When debugging issues with a workload using SysV shmem, Michal Hocko has
come up with a reproducer that shows how a series of mprotect() operations
can result in an elevated shm_nattch and thus leak of the resource.
The problem is caused by wrong assumptions in vma_merge() commit
714965ca82 ("mm/mmap: start distinguishing if vma can be removed in
mergeability test"). The shmem vmas have a vma_ops->close callback that
decrements shm_nattch, and we remove the vma without calling it.
vma_merge() has thus historically avoided merging vma's with
vma_ops->close and commit 714965ca82 was supposed to keep it that way.
It relaxed the checks for vma_ops->close in can_vma_merge_after() assuming
that it is never called on a vma that would be a candidate for removal.
However, the vma_merge() code does also use the result of this check in
the decision to remove a different vma in the merge case 7.
A robust solution would be to refactor vma_merge() code in a way that the
vma_ops->close check is only done for vma's that are actually going to be
removed, and not as part of the preliminary checks. That would both solve
the existing bug, and also allow additional merges that the checks
currently prevent unnecessarily in some cases.
However to fix the existing bug first with a minimized risk, and for
easier stable backports, this patch only adds a vma_ops->close check to
the buggy case 7 specifically. All other cases of vma removal are covered
by the can_vma_merge_before() check that includes the test for
vma_ops->close.
The reproducer code, adapted from Michal Hocko's code:
int main(int argc, char *argv[]) {
int segment_id;
size_t segment_size = 20 * PAGE_SIZE;
char * sh_mem;
struct shmid_ds shmid_ds;
key_t key = 0x1234;
segment_id = shmget(key, segment_size,
IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR);
sh_mem = (char *)shmat(segment_id, NULL, 0);
mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_NONE);
mprotect(sh_mem + PAGE_SIZE, PAGE_SIZE, PROT_WRITE);
mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_WRITE);
shmdt(sh_mem);
shmctl(segment_id, IPC_STAT, &shmid_ds);
printf("nattch after shmdt(): %lu (expected: 0)\n", shmid_ds.shm_nattch);
if (shmctl(segment_id, IPC_RMID, 0))
printf("IPCRM failed %d\n", errno);
return (shmid_ds.shm_nattch) ? 1 : 0;
}
Link: https://lkml.kernel.org/r/20240222215930.14637-2-vbabka@suse.cz
Fixes: 714965ca82 ("mm/mmap: start distinguishing if vma can be removed in mergeability test")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After ptep_clear_flush(), if we find that src_folio is pinned we will fail
UFFDIO_MOVE and put src_folio back to src_pte entry, but the change to
src_folio->{mapping,index} is not restored in this process. This is not
what we expected, so fix it.
This can cause the rmap for that page to be invalid, possibly resulting
in memory corruption. At least swapout+migration would no longer work,
because we might fail to locate the mappings of that folio.
Link: https://lkml.kernel.org/r/20240222080815.46291-1-zhengqi.arch@bytedance.com
Fixes: adef440691 ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sven reports an infinite loop in __alloc_pages_slowpath() for costly order
__GFP_RETRY_MAYFAIL allocations that are also GFP_NOIO. Such combination
can happen in a suspend/resume context where a GFP_KERNEL allocation can
have __GFP_IO masked out via gfp_allowed_mask.
Quoting Sven:
1. try to do a "costly" allocation (order > PAGE_ALLOC_COSTLY_ORDER)
with __GFP_RETRY_MAYFAIL set.
2. page alloc's __alloc_pages_slowpath tries to get a page from the
freelist. This fails because there is nothing free of that costly
order.
3. page alloc tries to reclaim by calling __alloc_pages_direct_reclaim,
which bails out because a zone is ready to be compacted; it pretends
to have made a single page of progress.
4. page alloc tries to compact, but this always bails out early because
__GFP_IO is not set (it's not passed by the snd allocator, and even
if it were, we are suspending so the __GFP_IO flag would be cleared
anyway).
5. page alloc believes reclaim progress was made (because of the
pretense in item 3) and so it checks whether it should retry
compaction. The compaction retry logic thinks it should try again,
because:
a) reclaim is needed because of the early bail-out in item 4
b) a zonelist is suitable for compaction
6. goto 2. indefinite stall.
(end quote)
The immediate root cause is confusing the COMPACT_SKIPPED returned from
__alloc_pages_direct_compact() (step 4) due to lack of __GFP_IO to be
indicating a lack of order-0 pages, and in step 5 evaluating that in
should_compact_retry() as a reason to retry, before incrementing and
limiting the number of retries. There are however other places that
wrongly assume that compaction can happen while we lack __GFP_IO.
To fix this, introduce gfp_compaction_allowed() to abstract the __GFP_IO
evaluation and switch the open-coded test in try_to_compact_pages() to use
it.
Also use the new helper in:
- compaction_ready(), which will make reclaim not bail out in step 3, so
there's at least one attempt to actually reclaim, even if chances are
small for a costly order
- in_reclaim_compaction() which will make should_continue_reclaim()
return false and we don't over-reclaim unnecessarily
- in __alloc_pages_slowpath() to set a local variable can_compact,
which is then used to avoid retrying reclaim/compaction for costly
allocations (step 5) if we can't compact and also to skip the early
compaction attempt that we do in some cases
Link: https://lkml.kernel.org/r/20240221114357.13655-2-vbabka@suse.cz
Fixes: 3250845d05 ("Revert "mm, oom: prevent premature OOM killer invocation for high order request"")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Sven van Ashbrook <svenva@chromium.org>
Closes: https://lore.kernel.org/all/CAG-rBihs_xMKb3wrMO1%2B-%2Bp4fowP9oy1pa_OTkfxBzPUVOZF%2Bg@mail.gmail.com/
Tested-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Curtis Malainey <cujomalainey@chromium.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This empty wrapped exists only for !CONFIG_MEMCG_KMEM and seems it was
never used. Probably a leftover from development of a series.
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
We already have the inc_slabs_node() after kmem_cache_node->node[node]
initialized in early_kmem_cache_node_alloc(), this special case of
inc_slabs_node() can be removed. Then we don't need to consider the
existence of kmem_cache_node in inc_slabs_node() anymore.
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Use the form of *@param which kernel-doc recognizes now.
This resolves the warnings from "make htmldocs" as reported in [1].
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: [1] https://lore.kernel.org/r/20240223153636.41358be5@canb.auug.org.au/
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
or aren't considered appropriate for backporting.
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Merge tag 'mm-hotfixes-stable-2024-02-27-14-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"Six hotfixes. Three are cc:stable and the remainder address post-6.7
issues or aren't considered appropriate for backporting"
* tag 'mm-hotfixes-stable-2024-02-27-14-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/debug_vm_pgtable: fix BUG_ON with pud advanced test
mm: cachestat: fix folio read-after-free in cache walk
MAINTAINERS: add memory mapping entry with reviewers
mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index
kasan: revert eviction of stack traces in generic mode
stackdepot: use variable size records for non-evictable entries
The SLAB_KASAN flag prevents merging of caches in some configurations,
which is handled in a rather complicated way via kasan_never_merge().
Since we now have a generic SLAB_NO_MERGE flag, we can instead use it
for KASAN caches in addition to SLAB_KASAN in those configurations,
and simplify the SLAB_NEVER_MERGE handling.
Tested-by: Xiongwei Song <xiongwei.song@windriver.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
The values of SLAB_ cache creation flags are defined by hand, which is
tedious and error-prone. Use an enum to assign the bit number and a
__SLAB_FLAG_BIT() macro to #define the final flags.
This renumbers the flag values, which is OK as they are only used
internally.
Also define a __SLAB_FLAG_UNUSED macro to assign value to flags disabled
by their respective config options in a unified and sparse-friendly way.
Reviewed-and-tested-by: Xiongwei Song <xiongwei.song@windriver.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was
removed. SLUB instead relies on the page allocator's NUMA policies.
Change the flag's value to 0 to free up the value it had, and mark it
for full removal once all users are gone.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Closes: https://lore.kernel.org/all/20240131172027.10f64405@gandalf.local.home/
Reviewed-and-tested-by: Xiongwei Song <xiongwei.song@windriver.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
- Fix NUMA initialization from ACPI CEDT.CFMWS
- Fix region assembly failures due to async init order
- Fix / simplify export of qos_class information
- Fix cxl_acpi initialization vs single-window-init failures
- Fix handling of repeated 'pci_channel_io_frozen' notifications
- Workaround platforms that violate host-physical-address ==
system-physical address assumptions
- Defer CXL CPER notification handling to v6.9
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Merge tag 'cxl-fixes-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull cxl fixes from Dan Williams:
"A collection of significant fixes for the CXL subsystem.
The largest change in this set, that bordered on "new development", is
the fix for the fact that the location of the new qos_class attribute
did not match the Documentation. The fix ends up deleting more code
than it added, and it has a new unit test to backstop basic errors in
this interface going forward. So the "red-diff" and unit test saved
the "rip it out and try again" response.
In contrast, the new notification path for firmware reported CXL
errors (CXL CPER notifications) has a locking context bug that can not
be fixed with a red-diff. Given where the release cycle stands, it is
not comfortable to squeeze in that fix in these waning days. So, that
receives the "back it out and try again later" treatment.
There is a regression fix in the code that establishes memory NUMA
nodes for platform CXL regions. That has an ack from x86 folks. There
are a couple more fixups for Linux to understand (reassemble) CXL
regions instantiated by platform firmware. The policy around platforms
that do not match host-physical-address with system-physical-address
(i.e. systems that have an address translation mechanism between the
address range reported in the ACPI CEDT.CFMWS and endpoint decoders)
has been softened to abort driver load rather than teardown the memory
range (can cause system hangs). Lastly, there is a robustness /
regression fix for cases where the driver would previously continue in
the face of error, and a fixup for PCI error notification handling.
Summary:
- Fix NUMA initialization from ACPI CEDT.CFMWS
- Fix region assembly failures due to async init order
- Fix / simplify export of qos_class information
- Fix cxl_acpi initialization vs single-window-init failures
- Fix handling of repeated 'pci_channel_io_frozen' notifications
- Workaround platforms that violate host-physical-address ==
system-physical address assumptions
- Defer CXL CPER notification handling to v6.9"
* tag 'cxl-fixes-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl/acpi: Fix load failures due to single window creation failure
acpi/ghes: Remove CXL CPER notifications
cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window
cxl/test: Add support for qos_class checking
cxl: Fix sysfs export of qos_class for memdev
cxl: Remove unnecessary type cast in cxl_qos_class_verify()
cxl: Change 'struct cxl_memdev_state' *_perf_list to single 'struct cxl_dpa_perf'
cxl/region: Allow out of order assembly of autodiscovered regions
cxl/region: Handle endpoint decoders in cxl_region_find_decoder()
x86/numa: Fix the sort compare func used in numa_fill_memblks()
x86/numa: Fix the address overlap check in numa_fill_memblks()
cxl/pci: Skip to handle RAS errors if CXL.mem device is detached
Use the new writeback_iter() directly instead of indirecting through a
callback.
[hch@lst.de: ported to the while based iter style]
Link: https://lkml.kernel.org/r/20240215063649.2164017-15-hch@lst.de
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Refactor the code left in write_cache_pages into an iterator that the file
system can call to get the next folio for a writeback operation:
struct folio *folio = NULL;
while ((folio = writeback_iter(mapping, wbc, folio, &error))) {
error = <do per-folio writeback>;
}
The twist here is that the error value is passed by reference, so that the
iterator can restore it when breaking out of the loop.
Handling of the magic AOP_WRITEPAGE_ACTIVATE value stays outside the
iterator and needs is just kept in the write_cache_pages legacy wrapper.
in preparation for eventually killing it off.
Heavily based on a for_each* based iterator from Matthew Wilcox.
Link: https://lkml.kernel.org/r/20240215063649.2164017-14-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move the loop for should-we-write-this-folio to writeback_get_folio.
[hch@lst.de: fold loop into existing helper instead of a separate one per Jan]
Link: https://lkml.kernel.org/r/20240215063649.2164017-13-hch@lst.de
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Instead of keeping our own local iterator variable, use the one just added
to folio_batch.
Link: https://lkml.kernel.org/r/20240215063649.2164017-12-hch@lst.de
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Collapse the two nested loops into one. This is needed as a step towards
turning this into an iterator.
Note that this drops the "index <= end" check in the previous outer loop
and just relies on filemap_get_folios_tag() to return 0 entries when index
> end. This actually has a subtle implication when end == -1 because then
the returned index will be -1 as well and thus if there is page present on
index -1, we could be looping indefinitely. But as the comment in
filemap_get_folios_tag documents this as already broken anyway we should
not worry about it here either. The fix for that would probably a change
to the filemap_get_folios_tag() calling convention.
[hch@lst.de: update the commit log per Jan]
Link: https://lkml.kernel.org/r/20240215063649.2164017-10-hch@lst.de
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This simple helper will be the basis of the writeback iterator. To make
this work, we need to remember the current index and end positions in
writeback_control.
[hch@lst.de: heavily rebased, add helpers to get the tag and end index, don't keep the end index in struct writeback_control]
Link: https://lkml.kernel.org/r/20240215063649.2164017-9-hch@lst.de
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
