Commit Graph

10723 Commits

Author SHA1 Message Date
Michal Hocko
b32eaf71db mm: clarify COMPACTION Kconfig text
The current wording of the COMPACTION Kconfig help text doesn't
emphasise that disabling COMPACTION might cripple the page allocator
which relies on the compaction quite heavily for high order requests and
an unexpected OOM can happen with the lack of compaction.  Make sure we
are vocal about that.

Link: http://lkml.kernel.org/r/20160823091726.GK23577@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-26 17:39:35 -07:00
Andrea Arcangeli
804dd15046 soft_dirty: fix soft_dirty during THP split
While adding proper userfaultfd_wp support with bits in pagetable and
swap entry to avoid false positives WP userfaults through swap/fork/
KSM/etc, I've been adding a framework that mostly mirrors soft dirty.

So I noticed in one place I had to add uffd_wp support to the pagetables
that wasn't covered by soft_dirty and I think it should have.

Example: in the THP migration code migrate_misplaced_transhuge_page()
pmd_mkdirty is called unconditionally after mk_huge_pmd.

	entry = mk_huge_pmd(new_page, vma->vm_page_prot);
	entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);

That sets soft dirty too (it's a false positive for soft dirty, the soft
dirty bit could be more finegrained and transfer the bit like uffd_wp
will do..  pmd/pte_uffd_wp() enforces the invariant that when it's set
pmd/pte_write is not set).

However in the THP split there's no unconditional pmd_mkdirty after
mk_huge_pmd and pte_swp_mksoft_dirty isn't called after the migration
entry is created.  The code sets the dirty bit in the struct page
instead of setting it in the pagetable (which is fully equivalent as far
as the real dirty bit is concerned, as the whole point of pagetable bits
is to be eventually flushed out of to the page, but that is not
equivalent for the soft-dirty bit that gets lost in translation).

This was found by code review only and totally untested as I'm working
to actually replace soft dirty and I don't have time to test potential
soft dirty bugfixes as well :).

Transfer the soft_dirty from pmd to pte during THP splits.

This fix avoids losing the soft_dirty bit and avoids userland memory
corruption in the checkpoint.

Fixes: eef1b3ba05 ("thp: implement split_huge_pmd()")
Link: http://lkml.kernel.org/r/1471610515-30229-2-git-send-email-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-26 17:39:35 -07:00
Catalin Marinas
cab15ce604 arm64: Introduce execute-only page access permissions
The ARMv8 architecture allows execute-only user permissions by clearing
the PTE_UXN and PTE_USER bits. However, the kernel running on a CPU
implementation without User Access Override (ARMv8.2 onwards) can still
access such page, so execute-only page permission does not protect
against read(2)/write(2) etc. accesses. Systems requiring such
protection must enable features like SECCOMP.

This patch changes the arm64 __P100 and __S100 protection_map[] macros
to the new __PAGE_EXECONLY attributes. A side effect is that
pte_user() no longer triggers for __PAGE_EXECONLY since PTE_USER isn't
set. To work around this, the check is done on the PTE_NG bit via the
pte_ng() macro. VM_READ is also checked now for page faults.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-25 18:00:29 +01:00
Josh Poimboeuf
94cd97af69 usercopy: fix overlap check for kernel text
When running with a local patch which moves the '_stext' symbol to the
very beginning of the kernel text area, I got the following panic with
CONFIG_HARDENED_USERCOPY:

  usercopy: kernel memory exposure attempt detected from ffff88103dfff000 (<linear kernel text>) (4096 bytes)
  ------------[ cut here ]------------
  kernel BUG at mm/usercopy.c:79!
  invalid opcode: 0000 [#1] SMP
  ...
  CPU: 0 PID: 4800 Comm: cp Not tainted 4.8.0-rc3.after+ #1
  Hardware name: Dell Inc. PowerEdge R720/0X3D66, BIOS 2.5.4 01/22/2016
  task: ffff880817444140 task.stack: ffff880816274000
  RIP: 0010:[<ffffffff8121c796>] __check_object_size+0x76/0x413
  RSP: 0018:ffff880816277c40 EFLAGS: 00010246
  RAX: 000000000000006b RBX: ffff88103dfff000 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffff88081f80dfa8 RDI: ffff88081f80dfa8
  RBP: ffff880816277c90 R08: 000000000000054c R09: 0000000000000000
  R10: 0000000000000005 R11: 0000000000000006 R12: 0000000000001000
  R13: ffff88103e000000 R14: ffff88103dffffff R15: 0000000000000001
  FS:  00007fb9d1750800(0000) GS:ffff88081f800000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000021d2000 CR3: 000000081a08f000 CR4: 00000000001406f0
  Stack:
   ffff880816277cc8 0000000000010000 000000043de07000 0000000000000000
   0000000000001000 ffff880816277e60 0000000000001000 ffff880816277e28
   000000000000c000 0000000000001000 ffff880816277ce8 ffffffff8136c3a6
  Call Trace:
   [<ffffffff8136c3a6>] copy_page_to_iter_iovec+0xa6/0x1c0
   [<ffffffff8136e766>] copy_page_to_iter+0x16/0x90
   [<ffffffff811970e3>] generic_file_read_iter+0x3e3/0x7c0
   [<ffffffffa06a738d>] ? xfs_file_buffered_aio_write+0xad/0x260 [xfs]
   [<ffffffff816e6262>] ? down_read+0x12/0x40
   [<ffffffffa06a61b1>] xfs_file_buffered_aio_read+0x51/0xc0 [xfs]
   [<ffffffffa06a6692>] xfs_file_read_iter+0x62/0xb0 [xfs]
   [<ffffffff812224cf>] __vfs_read+0xdf/0x130
   [<ffffffff81222c9e>] vfs_read+0x8e/0x140
   [<ffffffff81224195>] SyS_read+0x55/0xc0
   [<ffffffff81003a47>] do_syscall_64+0x67/0x160
   [<ffffffff816e8421>] entry_SYSCALL64_slow_path+0x25/0x25
  RIP: 0033:[<00007fb9d0c33c00>] 0x7fb9d0c33c00
  RSP: 002b:00007ffc9c262f28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
  RAX: ffffffffffffffda RBX: fffffffffff8ffff RCX: 00007fb9d0c33c00
  RDX: 0000000000010000 RSI: 00000000021c3000 RDI: 0000000000000004
  RBP: 00000000021c3000 R08: 0000000000000000 R09: 00007ffc9c264d6c
  R10: 00007ffc9c262c50 R11: 0000000000000246 R12: 0000000000010000
  R13: 00007ffc9c2630b0 R14: 0000000000000004 R15: 0000000000010000
  Code: 81 48 0f 44 d0 48 c7 c6 90 4d a3 81 48 c7 c0 bb b3 a2 81 48 0f 44 f0 4d 89 e1 48 89 d9 48 c7 c7 68 16 a3 81 31 c0 e8 f4 57 f7 ff <0f> 0b 48 8d 90 00 40 00 00 48 39 d3 0f 83 22 01 00 00 48 39 c3
  RIP  [<ffffffff8121c796>] __check_object_size+0x76/0x413
   RSP <ffff880816277c40>

The checked object's range [ffff88103dfff000, ffff88103e000000) is
valid, so there shouldn't have been a BUG.  The hardened usercopy code
got confused because the range's ending address is the same as the
kernel's text starting address at 0xffff88103e000000.  The overlap check
is slightly off.

Fixes: f5509cc18d ("mm: Hardened usercopy")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-22 19:10:51 -07:00
Eric Biggers
7329a65587 usercopy: avoid potentially undefined behavior in pointer math
check_bogus_address() checked for pointer overflow using this expression,
where 'ptr' has type 'const void *':

	ptr + n < ptr

Since pointer wraparound is undefined behavior, gcc at -O2 by default
treats it like the following, which would not behave as intended:

	(long)n < 0

Fortunately, this doesn't currently happen for kernel code because kernel
code is compiled with -fno-strict-overflow.  But the expression should be
fixed anyway to use well-defined integer arithmetic, since it could be
treated differently by different compilers in the future or could be
reported by tools checking for undefined behavior.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-22 19:07:55 -07:00
Reza Arbab
5830169f47 mm/memory_hotplug.c: initialize per_cpu_nodestats for hotadded pgdats
The following oops occurs after a pgdat is hotadded:

  Unable to handle kernel paging request for data at address 0x00c30001
  Faulting instruction address: 0xc00000000022f8f4
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter nls_utf8 isofs sg virtio_balloon uio_pdrv_genirq uio ip_tables xfs libcrc32c sr_mod cdrom sd_mod virtio_net ibmvscsi scsi_transport_srp virtio_pci virtio_ring virtio dm_mirror dm_region_hash dm_log dm_mod
  CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W 4.8.0-rc1-device #110
  task: c000000000ef3080 task.stack: c000000000f6c000
  NIP: c00000000022f8f4 LR: c00000000022f948 CTR: 0000000000000000
  REGS: c000000000f6fa50 TRAP: 0300   Tainted: G        W (4.8.0-rc1-device)
  MSR: 800000010280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]>  CR: 84002028  XER: 20000000
  CFAR: d000000001d2013c DAR: 0000000000c30001 DSISR: 40000000 SOFTE: 0
  NIP refresh_cpu_vm_stats+0x1a4/0x2f0
  LR refresh_cpu_vm_stats+0x1f8/0x2f0
  Call Trace:
    refresh_cpu_vm_stats+0x1f8/0x2f0 (unreliable)

Add per_cpu_nodestats initialization to the hotplug codepath.

Link: http://lkml.kernel.org/r/1470931473-7090-1-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11 16:58:14 -07:00
Geert Uytterhoeven
f33e6f0671 mm, oom: fix uninitialized ret in task_will_free_mem()
mm/oom_kill.c: In function `task_will_free_mem':
    mm/oom_kill.c:767: warning: `ret' may be used uninitialized in this function

If __task_will_free_mem() is never called inside the for_each_process()
loop, ret will not be initialized.

Fixes: 1af8bb4326 ("mm, oom: fortify task_will_free_mem()")
Link: http://lkml.kernel.org/r/1470255599-24841-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11 16:58:14 -07:00
Alexander Potapenko
bcbf0d566b kasan: remove the unnecessary WARN_ONCE from quarantine.c
It's quite unlikely that the user will so little memory that the per-CPU
quarantines won't fit into the given fraction of the available memory.
Even in that case he won't be able to do anything with the information
given in the warning.

Link: http://lkml.kernel.org/r/1470929182-101413-1-git-send-email-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11 16:58:14 -07:00
Vladimir Davydov
615d66c37c mm: memcontrol: fix memcg id ref counter on swap charge move
Since commit 73f576c04b ("mm: memcontrol: fix cgroup creation failure
after many small jobs") swap entries do not pin memcg->css.refcnt
directly.  Instead, they pin memcg->id.ref.  So we should adjust the
reference counters accordingly when moving swap charges between cgroups.

Fixes: 73f576c04b ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11 16:58:13 -07:00
Vladimir Davydov
1f47b61fb4 mm: memcontrol: fix swap counter leak on swapout from offline cgroup
An offline memory cgroup might have anonymous memory or shmem left
charged to it and no swap.  Since only swap entries pin the id of an
offline cgroup, such a cgroup will have no id and so an attempt to
swapout its anon/shmem will not store memory cgroup info in the swap
cgroup map.  As a result, memcg->swap or memcg->memsw will never get
uncharged from it and any of its ascendants.

Fix this by always charging swapout to the first ancestor cgroup that
hasn't released its id yet.

[hannes@cmpxchg.org: add comment to mem_cgroup_swapout]
[vdavydov@virtuozzo.com: use WARN_ON_ONCE() in mem_cgroup_id_get_online()]
  Link: http://lkml.kernel.org/r/20160803123445.GJ13263@esperanza
Fixes: 73f576c04b ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/5336daa5c9a32e776067773d9da655d2dc126491.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>	[3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11 16:58:13 -07:00
Mel Gorman
2f95ff90b9 proc, meminfo: use correct helpers for calculating LRU sizes in meminfo
meminfo_proc_show() and si_mem_available() are using the wrong helpers
for calculating the size of the LRUs.  The user-visible impact is that
there appears to be an abnormally high number of unevictable pages.

Link: http://lkml.kernel.org/r/20160805105805.GR2799@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11 16:58:13 -07:00
zhong jiang
c1470b33bb mm/hugetlb: fix incorrect hugepages count during mem hotplug
When memory hotplug operates, free hugepages will be freed if the
movable node is offline.  Therefore, /proc/sys/vm/nr_hugepages will be
incorrect.

Fix it by reducing max_huge_pages when the node is offlined.

n-horiguchi@ah.jp.nec.com said:

: dissolve_free_huge_page intends to break a hugepage into buddy, and the
: destination hugepage is supposed to be allocated from the pool of the
: destination node, so the system-wide pool size is reduced.  So adding
: h->max_huge_pages-- makes sense to me.

Link: http://lkml.kernel.org/r/1470624546-902-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-11 16:58:13 -07:00
Chris Wilson
6039892396 mm/slub.c: run free_partial() outside of the kmem_cache_node->list_lock
With debugobjects enabled and using SLAB_DESTROY_BY_RCU, when a
kmem_cache_node is destroyed the call_rcu() may trigger a slab
allocation to fill the debug object pool (__debug_object_init:fill_pool).

Everywhere but during kmem_cache_destroy(), discard_slab() is performed
outside of the kmem_cache_node->list_lock and avoids a lockdep warning
about potential recursion:

  =============================================
  [ INFO: possible recursive locking detected ]
  4.8.0-rc1-gfxbench+ #1 Tainted: G     U
  ---------------------------------------------
  rmmod/8895 is trying to acquire lock:
   (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811c80d7>] get_partial_node.isra.63+0x47/0x430

  but task is already holding lock:
   (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811cbda4>] __kmem_cache_shutdown+0x54/0x320

  other info that might help us debug this:
  Possible unsafe locking scenario:
        CPU0
        ----
   lock(&(&n->list_lock)->rlock);
   lock(&(&n->list_lock)->rlock);

   *** DEADLOCK ***
   May be due to missing lock nesting notation
   5 locks held by rmmod/8895:
   #0:  (&dev->mutex){......}, at: driver_detach+0x42/0xc0
   #1:  (&dev->mutex){......}, at: driver_detach+0x50/0xc0
   #2:  (cpu_hotplug.dep_map){++++++}, at: get_online_cpus+0x2d/0x80
   #3:  (slab_mutex){+.+.+.}, at: kmem_cache_destroy+0x3c/0x220
   #4:  (&(&n->list_lock)->rlock){-.-...}, at: __kmem_cache_shutdown+0x54/0x320

  stack backtrace:
  CPU: 6 PID: 8895 Comm: rmmod Tainted: G     U          4.8.0-rc1-gfxbench+ #1
  Hardware name: Gigabyte Technology Co., Ltd. H87M-D3H/H87M-D3H, BIOS F11 08/18/2015
  Call Trace:
    __lock_acquire+0x1646/0x1ad0
    lock_acquire+0xb2/0x200
    _raw_spin_lock+0x36/0x50
    get_partial_node.isra.63+0x47/0x430
    ___slab_alloc.constprop.67+0x1a7/0x3b0
    __slab_alloc.isra.64.constprop.66+0x43/0x80
    kmem_cache_alloc+0x236/0x2d0
    __debug_object_init+0x2de/0x400
    debug_object_activate+0x109/0x1e0
    __call_rcu.constprop.63+0x32/0x2f0
    call_rcu+0x12/0x20
    discard_slab+0x3d/0x40
    __kmem_cache_shutdown+0xdb/0x320
    shutdown_cache+0x19/0x60
    kmem_cache_destroy+0x1ae/0x220
    i915_gem_load_cleanup+0x14/0x40 [i915]
    i915_driver_unload+0x151/0x180 [i915]
    i915_pci_remove+0x14/0x20 [i915]
    pci_device_remove+0x34/0xb0
    __device_release_driver+0x95/0x140
    driver_detach+0xb6/0xc0
    bus_remove_driver+0x53/0xd0
    driver_unregister+0x27/0x50
    pci_unregister_driver+0x25/0x70
    i915_exit+0x1a/0x1e2 [i915]
    SyS_delete_module+0x193/0x1f0
    entry_SYSCALL_64_fastpath+0x1c/0xac

Fixes: 52b4b950b5 ("mm: slab: free kmem_cache_node after destroy sysfs file")
Link: http://lkml.kernel.org/r/1470759070-18743-1-git-send-email-chris@chris-wilson.co.uk
Reported-by: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Gordon <david.s.gordon@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10 16:40:56 -07:00
Steve Capper
57dea93ac4 rmap: fix compound check logic in page_remove_file_rmap
In page_remove_file_rmap(.) we have the following check:

  VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);

This is meant to check for either HugeTLB pages or THP when a compound
page is passed in.

Unfortunately, if one disables CONFIG_TRANSPARENT_HUGEPAGE, then
PageTransHuge(.) will always return false, provoking BUGs when one runs
the libhugetlbfs test suite.

This patch replaces PageTransHuge(), with PageHead() which will work for
both HugeTLB and THP.

Fixes: dd78fedde4 ("rmap: support file thp")
Link: http://lkml.kernel.org/r/1470838217-5889-1-git-send-email-steve.capper@arm.com
Signed-off-by: Steve Capper <steve.capper@arm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Shijie <shijie.huang@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10 16:40:56 -07:00
Kirill A. Shutemov
c8efc390c1 mm, rmap: fix false positive VM_BUG() in page_add_file_rmap()
PageTransCompound() doesn't distinguish THP from from any other type of
compound pages.  This can lead to false-positive VM_BUG_ON() in
page_add_file_rmap() if called on compound page from a driver[1].

I think we can exclude such cases by checking if the page belong to a
mapping.

The VM_BUG_ON_PAGE() is downgraded to VM_WARN_ON_ONCE().  This path
should not cause any harm to non-THP page, but good to know if we step
on anything else.

[1] http://lkml.kernel.org/r/c711e067-0bff-a6cb-3c37-04dfe77d2db1@redhat.com

Link: http://lkml.kernel.org/r/20160810161345.GA67522@black.fi.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Laura Abbott <labbott@redhat.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10 16:40:56 -07:00
Joonsoo Kim
6423aa8192 mm/page_alloc.c: recalculate some of node threshold when on/offline memory
Some of node threshold depends on number of managed pages in the node.
When memory is going on/offline, it can be changed and we need to adjust
them.

Add recalculation to appropriate places and clean-up related functions
for better maintenance.

Link: http://lkml.kernel.org/r/1470724248-26780-2-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10 16:40:56 -07:00
Joonsoo Kim
81cbcbc2d8 mm/page_alloc.c: fix wrong initialization when sysctl_min_unmapped_ratio changes
Before resetting min_unmapped_pages, we need to initialize
min_unmapped_pages rather than min_slab_pages.

Fixes: a5f5f91da6 (mm: convert zone_reclaim to node_reclaim)
Link: http://lkml.kernel.org/r/1470724248-26780-1-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10 16:40:56 -07:00
Arnd Bergmann
3b33719c9b thp: move shmem_huge_enabled() outside of SYSFS ifdef
The newly introduced shmem_huge_enabled() function has two definitions,
but neither of them is visible if CONFIG_SYSFS is disabled, leading to a
build error:

  mm/khugepaged.o: In function `khugepaged':
  khugepaged.c:(.text.khugepaged+0x3ca): undefined reference to `shmem_huge_enabled'

This changes the #ifdef guards around the definition to match those that
are used in the header file.

Fixes: e496cf3d78 ("thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE")
Link: http://lkml.kernel.org/r/20160809123638.1357593-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-10 16:40:56 -07:00
Vladimir Davydov
c4159a75b6 mm: memcontrol: only mark charged pages with PageKmemcg
To distinguish non-slab pages charged to kmemcg we mark them PageKmemcg,
which sets page->_mapcount to -512.  Currently, we set/clear PageKmemcg
in __alloc_pages_nodemask()/free_pages_prepare() for any page allocated
with __GFP_ACCOUNT, including those that aren't actually charged to any
cgroup, i.e. allocated from the root cgroup context.  To avoid overhead
in case cgroups are not used, we only do that if memcg_kmem_enabled() is
true.  The latter is set iff there are kmem-enabled memory cgroups
(online or offline).  The root cgroup is not considered kmem-enabled.

As a result, if a page is allocated with __GFP_ACCOUNT for the root
cgroup when there are kmem-enabled memory cgroups and is freed after all
kmem-enabled memory cgroups were removed, e.g.

  # no memory cgroups has been created yet, create one
  mkdir /sys/fs/cgroup/memory/test
  # run something allocating pages with __GFP_ACCOUNT, e.g.
  # a program using pipe
  dmesg | tail
  # remove the memory cgroup
  rmdir /sys/fs/cgroup/memory/test

we'll get bad page state bug complaining about page->_mapcount != -1:

  BUG: Bad page state in process swapper/0  pfn:1fd945c
  page:ffffea007f651700 count:0 mapcount:-511 mapping:          (null) index:0x0
  flags: 0x1000000000000000()

To avoid that, let's mark with PageKmemcg only those pages that are
actually charged to and hence pin a non-root memory cgroup.

Fixes: 4949148ad4 ("mm: charge/uncharge kmemcg from generic page allocator paths")
Reported-and-tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-09 10:14:10 -07:00
Linus Torvalds
1eccfa090e Implements HARDENED_USERCOPY verification of copy_to_user/copy_from_user
bounds checking for most architectures on SLAB and SLUB.
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Merge tag 'usercopy-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull usercopy protection from Kees Cook:
 "Tbhis implements HARDENED_USERCOPY verification of copy_to_user and
  copy_from_user bounds checking for most architectures on SLAB and
  SLUB"

* tag 'usercopy-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  mm: SLUB hardened usercopy support
  mm: SLAB hardened usercopy support
  s390/uaccess: Enable hardened usercopy
  sparc/uaccess: Enable hardened usercopy
  powerpc/uaccess: Enable hardened usercopy
  ia64/uaccess: Enable hardened usercopy
  arm64/uaccess: Enable hardened usercopy
  ARM: uaccess: Enable hardened usercopy
  x86/uaccess: Enable hardened usercopy
  mm: Hardened usercopy
  mm: Implement stack frame object validation
  mm: Add is_migrate_cma_page
2016-08-08 14:48:14 -07:00
Jens Axboe
ba13e83ec3 mm: make __swap_writepage() use bio_set_op_attrs()
Cleaner than manipulating bio->bi_rw flags directly.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07 14:41:02 -06:00
Jens Axboe
c11f0c0b5b block/mm: make bdev_ops->rw_page() take a bool for read/write
Commit abf545484d changed it from an 'rw' flags type to the
newer ops based interface, but now we're effectively leaking
some bdev internals to the rest of the kernel. Since we only
care about whether it's a read or a write at that level, just
pass in a bool 'is_write' parameter instead.

Then we can also move op_is_write() and friends back under
CONFIG_BLOCK protection.

Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07 14:41:02 -06:00
Linus Torvalds
fff648da96 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "Here's the second round of block updates for this merge window.

  It's a mix of fixes for changes that went in previously in this round,
  and fixes in general.  This pull request contains:

   - Fixes for loop from Christoph

   - A bdi vs gendisk lifetime fix from Dan, worth two cookies.

   - A blk-mq timeout fix, when on frozen queues.  From Gabriel.

   - Writeback fix from Jan, ensuring that __writeback_single_inode()
     does the right thing.

   - Fix for bio->bi_rw usage in f2fs from me.

   - Error path deadlock fix in blk-mq sysfs registration from me.

   - Floppy O_ACCMODE fix from Jiri.

   - Fix to the new bio op methods from Mike.

     One more followup will be coming here, ensuring that we don't
     propagate the block types outside of block.  That, and a rename of
     bio->bi_rw is coming right after -rc1 is cut.

   - Various little fixes"

* 'for-linus' of git://git.kernel.dk/linux-block:
  mm/block: convert rw_page users to bio op use
  loop: make do_req_filebacked more robust
  loop: don't try to use AIO for discards
  blk-mq: fix deadlock in blk_mq_register_disk() error path
  Include: blkdev: Removed duplicate 'struct request;' declaration.
  Fixup direct bi_rw modifiers
  block: fix bdi vs gendisk lifetime mismatch
  blk-mq: Allow timeouts to run while queue is freezing
  nbd: fix race in ioctl
  block: fix use-after-free in seq file
  f2fs: drop bio->bi_rw manual assignment
  block: add missing group association in bio-cloning functions
  blkcg: kill unused field nr_undestroyed_grps
  writeback: Write dirty times for WB_SYNC_ALL writeback
  floppy: fix open(O_ACCMODE) for ioctl-only open
2016-08-05 23:31:51 -04:00
Linus Torvalds
2cfd716d27 powerpc updates for 4.8 #2
Fixes:
  - Fix early access to cpu_spec relocation from Benjamin Herrenschmidt
  - Fix incorrect event codes in power9-event-list from Madhavan Srinivasan
  - Move register_process_table() out of ppc_md from Michael Ellerman
 
 Use jump_label for [cpu|mmu]_has_feature() from Aneesh Kumar K.V, Kevin Hao and Michael Ellerman:
  - Add mmu_early_init_devtree() from Michael Ellerman
  - Move disable_radix handling into mmu_early_init_devtree() from Michael Ellerman
  - Do hash device tree scanning earlier from Michael Ellerman
  - Do radix device tree scanning earlier from Michael Ellerman
  - Do feature patching before MMU init from Michael Ellerman
  - Check features don't change after patching from Michael Ellerman
  - Make MMU_FTR_RADIX a MMU family feature from Aneesh Kumar K.V
  - Convert mmu_has_feature() to returning bool from Michael Ellerman
  - Convert cpu_has_feature() to returning bool from Michael Ellerman
  - Define radix_enabled() in one place & use static inline from Michael Ellerman
  - Add early_[cpu|mmu]_has_feature() from Michael Ellerman
  - Convert early cpu/mmu feature check to use the new helpers from Aneesh Kumar K.V
  - jump_label: Make it possible for arches to invoke jump_label_init() earlier from Kevin Hao
  - Call jump_label_init() in apply_feature_fixups() from Aneesh Kumar K.V
  - Remove mfvtb() from Kevin Hao
  - Move cpu_has_feature() to a separate file from Kevin Hao
  - Add kconfig option to use jump labels for cpu/mmu_has_feature() from Michael Ellerman
  - Add option to use jump label for cpu_has_feature() from Kevin Hao
  - Add option to use jump label for mmu_has_feature() from Kevin Hao
  - Catch usage of cpu/mmu_has_feature() before jump label init from Aneesh Kumar K.V
  - Annotate jump label assembly from Michael Ellerman
 
 TLB flush enhancements from Aneesh Kumar K.V:
  - radix: Implement tlb mmu gather flush efficiently
  - Add helper for finding SLBE LLP encoding
  - Use hugetlb flush functions
  - Drop multiple definition of mm_is_core_local
  - radix: Add tlb flush of THP ptes
  - radix: Rename function and drop unused arg
  - radix/hugetlb: Add helper for finding page size
  - hugetlb: Add flush_hugetlb_tlb_range
  - remove flush_tlb_page_nohash
 
 Add new ptrace regsets from Anshuman Khandual and Simon Guo:
  - elf: Add powerpc specific core note sections
  - Add the function flush_tmregs_to_thread
  - Enable in transaction NT_PRFPREG ptrace requests
  - Enable in transaction NT_PPC_VMX ptrace requests
  - Enable in transaction NT_PPC_VSX ptrace requests
  - Adapt gpr32_get, gpr32_set functions for transaction
  - Enable support for NT_PPC_CGPR
  - Enable support for NT_PPC_CFPR
  - Enable support for NT_PPC_CVMX
  - Enable support for NT_PPC_CVSX
  - Enable support for TM SPR state
  - Enable NT_PPC_TM_CTAR, NT_PPC_TM_CPPR, NT_PPC_TM_CDSCR
  - Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR
  - Enable support for EBB registers
  - Enable support for Performance Monitor registers
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Merge tag 'powerpc-4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull more powerpc updates from Michael Ellerman:
 "These were delayed for various reasons, so I let them sit in next a
  bit longer, rather than including them in my first pull request.

  Fixes:
   - Fix early access to cpu_spec relocation from Benjamin Herrenschmidt
   - Fix incorrect event codes in power9-event-list from Madhavan Srinivasan
   - Move register_process_table() out of ppc_md from Michael Ellerman

  Use jump_label use for [cpu|mmu]_has_feature():
   - Add mmu_early_init_devtree() from Michael Ellerman
   - Move disable_radix handling into mmu_early_init_devtree() from Michael Ellerman
   - Do hash device tree scanning earlier from Michael Ellerman
   - Do radix device tree scanning earlier from Michael Ellerman
   - Do feature patching before MMU init from Michael Ellerman
   - Check features don't change after patching from Michael Ellerman
   - Make MMU_FTR_RADIX a MMU family feature from Aneesh Kumar K.V
   - Convert mmu_has_feature() to returning bool from Michael Ellerman
   - Convert cpu_has_feature() to returning bool from Michael Ellerman
   - Define radix_enabled() in one place & use static inline from Michael Ellerman
   - Add early_[cpu|mmu]_has_feature() from Michael Ellerman
   - Convert early cpu/mmu feature check to use the new helpers from Aneesh Kumar K.V
   - jump_label: Make it possible for arches to invoke jump_label_init() earlier from Kevin Hao
   - Call jump_label_init() in apply_feature_fixups() from Aneesh Kumar K.V
   - Remove mfvtb() from Kevin Hao
   - Move cpu_has_feature() to a separate file from Kevin Hao
   - Add kconfig option to use jump labels for cpu/mmu_has_feature() from Michael Ellerman
   - Add option to use jump label for cpu_has_feature() from Kevin Hao
   - Add option to use jump label for mmu_has_feature() from Kevin Hao
   - Catch usage of cpu/mmu_has_feature() before jump label init from Aneesh Kumar K.V
   - Annotate jump label assembly from Michael Ellerman

  TLB flush enhancements from Aneesh Kumar K.V:
   - radix: Implement tlb mmu gather flush efficiently
   - Add helper for finding SLBE LLP encoding
   - Use hugetlb flush functions
   - Drop multiple definition of mm_is_core_local
   - radix: Add tlb flush of THP ptes
   - radix: Rename function and drop unused arg
   - radix/hugetlb: Add helper for finding page size
   - hugetlb: Add flush_hugetlb_tlb_range
   - remove flush_tlb_page_nohash

  Add new ptrace regsets from Anshuman Khandual and Simon Guo:
   - elf: Add powerpc specific core note sections
   - Add the function flush_tmregs_to_thread
   - Enable in transaction NT_PRFPREG ptrace requests
   - Enable in transaction NT_PPC_VMX ptrace requests
   - Enable in transaction NT_PPC_VSX ptrace requests
   - Adapt gpr32_get, gpr32_set functions for transaction
   - Enable support for NT_PPC_CGPR
   - Enable support for NT_PPC_CFPR
   - Enable support for NT_PPC_CVMX
   - Enable support for NT_PPC_CVSX
   - Enable support for TM SPR state
   - Enable NT_PPC_TM_CTAR, NT_PPC_TM_CPPR, NT_PPC_TM_CDSCR
   - Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR
   - Enable support for EBB registers
   - Enable support for Performance Monitor registers"

* tag 'powerpc-4.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (48 commits)
  powerpc/mm: Move register_process_table() out of ppc_md
  powerpc/perf: Fix incorrect event codes in power9-event-list
  powerpc/32: Fix early access to cpu_spec relocation
  powerpc/ptrace: Enable support for Performance Monitor registers
  powerpc/ptrace: Enable support for EBB registers
  powerpc/ptrace: Enable support for NT_PPPC_TAR, NT_PPC_PPR, NT_PPC_DSCR
  powerpc/ptrace: Enable NT_PPC_TM_CTAR, NT_PPC_TM_CPPR, NT_PPC_TM_CDSCR
  powerpc/ptrace: Enable support for TM SPR state
  powerpc/ptrace: Enable support for NT_PPC_CVSX
  powerpc/ptrace: Enable support for NT_PPC_CVMX
  powerpc/ptrace: Enable support for NT_PPC_CFPR
  powerpc/ptrace: Enable support for NT_PPC_CGPR
  powerpc/ptrace: Adapt gpr32_get, gpr32_set functions for transaction
  powerpc/ptrace: Enable in transaction NT_PPC_VSX ptrace requests
  powerpc/ptrace: Enable in transaction NT_PPC_VMX ptrace requests
  powerpc/ptrace: Enable in transaction NT_PRFPREG ptrace requests
  powerpc/process: Add the function flush_tmregs_to_thread
  elf: Add powerpc specific core note sections
  powerpc/mm: remove flush_tlb_page_nohash
  powerpc/mm/hugetlb: Add flush_hugetlb_tlb_range
  ...
2016-08-05 09:00:54 -04:00
zijun_hu
e47608ab6d mm/memblock.c: fix NULL dereference error
It causes NULL dereference error and failure to get type_a->regions[0]
info if parameter type_b of __next_mem_range_rev() == NULL

Fix this by checking before dereferring and initializing idx_b to 0

The approach is tested by dumping all types of region via
__memblock_dump_all() and __next_mem_range_rev() fixed to UART
separately the result is okay after checking the logs.

Link: http://lkml.kernel.org/r/57A0320D.6070102@zoho.com
Signed-off-by: zijun_hu <zijun_hu@htc.com>
Tested-by: zijun_hu <zijun_hu@htc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04 20:02:09 -04:00
Geert Uytterhoeven
117d54df7a slub: drop bogus inline for fixup_red_left()
With m68k-linux-gnu-gcc-4.1:

    include/linux/slub_def.h:126: warning: `fixup_red_left' declared inline after being called
    include/linux/slub_def.h:126: warning: previous declaration of `fixup_red_left' was here

Commit c146a2b98e ("mm, kasan: account for object redzone in SLUB's
nearest_obj()") made fixup_red_left() global, but forgot to remove the
inline keyword.

Fixes: c146a2b98e ("mm, kasan: account for object redzone in SLUB's nearest_obj()")
Link: http://lkml.kernel.org/r/1470256262-1586-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Alexander Potapenko <glider@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04 20:02:09 -04:00
Mel Gorman
b4911ea2bc mm: initialise per_cpu_nodestats for all online pgdats at boot
Paul Mackerras and Reza Arbab reported that machines with memoryless
nodes fail when vmstats are refreshed.  Paul reported an oops as follows

  Unable to handle kernel paging request for data at address 0xff7a10000
  Faulting instruction address: 0xc000000000270cd0
  Oops: Kernel access of bad area, sig: 11 [#1]
  SMP NR_CPUS=2048 NUMA PowerNV
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-kvm+ #118
  task: c000000ff0680010 task.stack: c000000ff0704000
  NIP: c000000000270cd0 LR: c000000000270ce8 CTR: 0000000000000000
  REGS: c000000ff0707900 TRAP: 0300   Not tainted  (4.7.0-kvm+)
  MSR: 9000000102009033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]>  CR: 846b6824  XER: 20000000
  CFAR: c000000000008768 DAR: 0000000ff7a10000 DSISR: 42000000 SOFTE: 1
  NIP refresh_zone_stat_thresholds+0x80/0x240
  LR refresh_zone_stat_thresholds+0x98/0x240
  Call Trace:
    refresh_zone_stat_thresholds+0xb8/0x240 (unreliable)

Both supplied potential fixes but one potentially misses checks and
another had redundant initialisations.  This version initialises
per_cpu_nodestats on a per-pgdat basis instead of on a per-zone basis.

Link: http://lkml.kernel.org/r/20160804092404.GI2799@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Paul Mackerras <paulus@ozlabs.org>
Reported-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04 20:02:09 -04:00
Alexander Kuleshov
412d0008d6 mm/memblock: fix a typo in a comment
s/accomodate/accommodate/

Link: http://lkml.kernel.org/r/20160804121824.18100-1-kuleshovmail@gmail.com
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04 20:02:09 -04:00
zhong jiang
1e185736d2 mm: disable CONFIG_MEMORY_HOTPLUG when KASAN is enabled
At present it is obvious that memory online and offline will fail when
KASAN is enabled.  So add the condition to limit the memory_hotplug when
KASAN is enabled.

Link: http://lkml.kernel.org/r/1470063651-29519-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04 20:02:09 -04:00
Mike Christie
abf545484d mm/block: convert rw_page users to bio op use
The rw_page users were not converted to use bio/req ops. As a result
bdev_write_page is not passing down REQ_OP_WRITE and the IOs will
be sent down as reads.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Fixes: 4e1b2d52a8 ("block, fs, drivers: remove REQ_OP compat defs and related code")

Modified by me to:

1) Drop op_flags passing into ->rw_page(), as we don't use it.
2) Make op_is_write() and friends safe to use for !CONFIG_BLOCK

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04 14:25:33 -06:00
Dan Williams
df08c32ce3 block: fix bdi vs gendisk lifetime mismatch
The name for a bdi of a gendisk is derived from the gendisk's devt.
However, since the gendisk is destroyed before the bdi it leaves a
window where a new gendisk could dynamically reuse the same devt while a
bdi with the same name is still live.  Arrange for the bdi to hold a
reference against its "owner" disk device while it is registered.
Otherwise we can hit sysfs duplicate name collisions like the following:

 WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80
 sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1'

 Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015
  0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec
  ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351
  0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8
 Call Trace:
  [<ffffffff8134caec>] dump_stack+0x63/0x87
  [<ffffffff8108c351>] __warn+0xd1/0xf0
  [<ffffffff8108c3cf>] warn_slowpath_fmt+0x5f/0x80
  [<ffffffff812a0d34>] sysfs_warn_dup+0x64/0x80
  [<ffffffff812a0e1e>] sysfs_create_dir_ns+0x7e/0x90
  [<ffffffff8134faaa>] kobject_add_internal+0xaa/0x320
  [<ffffffff81358d4e>] ? vsnprintf+0x34e/0x4d0
  [<ffffffff8134ff55>] kobject_add+0x75/0xd0
  [<ffffffff816e66b2>] ? mutex_lock+0x12/0x2f
  [<ffffffff8148b0a5>] device_add+0x125/0x610
  [<ffffffff8148b788>] device_create_groups_vargs+0xd8/0x100
  [<ffffffff8148b7cc>] device_create_vargs+0x1c/0x20
  [<ffffffff811b775c>] bdi_register+0x8c/0x180
  [<ffffffff811b7877>] bdi_register_dev+0x27/0x30
  [<ffffffff813317f5>] add_disk+0x175/0x4a0

Cc: <stable@vger.kernel.org>
Reported-by: Yi Zhang <yizhan@redhat.com>
Tested-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Fixed up missing 0 return in bdi_register_owner().

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-04 14:19:16 -06:00
Geert Uytterhoeven
4620a06e4b shmem: Fix link error if huge pages support is disabled
If CONFIG_TRANSPARENT_HUGE_PAGECACHE=n, HPAGE_PMD_NR evaluates to
BUILD_BUG_ON(), and may cause (e.g. with gcc 4.12):

    mm/built-in.o: In function `shmem_alloc_hugepage':
    shmem.c:(.text+0x17570): undefined reference to `__compiletime_assert_1365'

To fix this, move the assignment to hindex after the check for huge
pages support.

Fixes: 800d8c63b2 ("shmem: add huge pages support")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-03 18:20:12 -04:00
Linus Torvalds
d52bd54db8 Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton:

 - the rest of ocfs2

 - various hotfixes, mainly MM

 - quite a bit of misc stuff - drivers, fork, exec, signals, etc.

 - printk updates

 - firmware

 - checkpatch

 - nilfs2

 - more kexec stuff than usual

 - rapidio updates

 - w1 things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits)
  ipc: delete "nr_ipc_ns"
  kcov: allow more fine-grained coverage instrumentation
  init/Kconfig: add clarification for out-of-tree modules
  config: add android config fragments
  init/Kconfig: ban CONFIG_LOCALVERSION_AUTO with allmodconfig
  relay: add global mode support for buffer-only channels
  init: allow blacklisting of module_init functions
  w1:omap_hdq: fix regression
  w1: add helper macro module_w1_family
  w1: remove need for ida and use PLATFORM_DEVID_AUTO
  rapidio/switches: add driver for IDT gen3 switches
  powerpc/fsl_rio: apply changes for RIO spec rev 3
  rapidio: modify for rev.3 specification changes
  rapidio: change inbound window size type to u64
  rapidio/idt_gen2: fix locking warning
  rapidio: fix error handling in mbox request/release functions
  rapidio/tsi721_dma: advance queue processing from transfer submit call
  rapidio/tsi721: add messaging mbox selector parameter
  rapidio/tsi721: add PCIe MRRS override parameter
  rapidio/tsi721_dma: add channel mask and queue size parameters
  ...
2016-08-02 21:08:07 -04:00
Kees Cook
ba093a6d93 mm: refuse wrapped vm_brk requests
The vm_brk() alignment calculations should refuse to overflow.  The ELF
loader depending on this, but it has been fixed now.  No other unsafe
callers have been found.

Link: http://lkml.kernel.org/r/1468014494-25291-3-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Ismael Ripoll Ripoll <iripoll@upv.es>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:15 -04:00
Fabian Frederick
bd721ea73e treewide: replace obsolete _refok by __ref
There was only one use of __initdata_refok and __exit_refok

__init_refok was used 46 times against 82 for __ref.

Those definitions are obsolete since commit 312b1485fb ("Introduce new
section reference annotations tags: __ref, __refdata, __refconst")

This patch removes the following compatibility definitions and replaces
them treewide.

/* compatibility defines */
#define __init_refok     __ref
#define __initdata_refok __refdata
#define __exit_refok     __ref

I can also provide separate patches if necessary.
(One patch per tree and check in 1 month or 2 to remove old definitions)

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1466796271-3043-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Vladimir Davydov
b5afba2974 mm: vmscan: fix memcg-aware shrinkers not called on global reclaim
We must call shrink_slab() for each memory cgroup on both global and
memcg reclaim in shrink_node_memcg().  Commit d71df22b55099 accidentally
changed that so that now shrink_slab() is only called with memcg != NULL
on memcg reclaim.  As a result, memcg-aware shrinkers (including
dentry/inode) are never invoked on global reclaim.  Fix that.

Fixes: b2e18757f2 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Link: http://lkml.kernel.org/r/1470056590-7177-1-git-send-email-vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Alexander Potapenko
c3cee37228 kasan: avoid overflowing quarantine size on low memory systems
If the total amount of memory assigned to quarantine is less than the
amount of memory assigned to per-cpu quarantines, |new_quarantine_size|
may overflow.  Instead, set it to zero.

[akpm@linux-foundation.org: cleanup: use WARN_ONCE return value]
Link: http://lkml.kernel.org/r/1470063563-96266-1-git-send-email-glider@google.com
Fixes: 55834c5909 ("mm: kasan: initial memory quarantine implementation")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
7e08897893 kasan: improve double-free reports
Currently we just dump stack in case of double free bug.
Let's dump all info about the object that we have.

[aryabinin@virtuozzo.com: change double free message per Alexander]
  Link: http://lkml.kernel.org/r/1470153654-30160-1-git-send-email-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/1470062715-14077-6-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
b3cbd9bf77 mm/kasan: get rid of ->state in struct kasan_alloc_meta
The state of object currently tracked in two places - shadow memory, and
the ->state field in struct kasan_alloc_meta.  We can get rid of the
latter.  The will save us a little bit of memory.  Also, this allow us
to move free stack into struct kasan_alloc_meta, without increasing
memory consumption.  So now we should always know when the last time the
object was freed.  This may be useful for long delayed use-after-free
bugs.

As a side effect this fixes following UBSAN warning:
	UBSAN: Undefined behaviour in mm/kasan/quarantine.c:102:13
	member access within misaligned address ffff88000d1efebc for type 'struct qlist_node'
	which requires 8 byte alignment

Link: http://lkml.kernel.org/r/1470062715-14077-5-git-send-email-aryabinin@virtuozzo.com
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
47b5c2a0f0 mm/kasan: get rid of ->alloc_size in struct kasan_alloc_meta
Size of slab object already stored in cache->object_size.

Note, that kmalloc() internally rounds up size of allocation, so
object_size may be not equal to alloc_size, but, usually we don't need
to know the exact size of allocated object.  In case if we need that
information, we still can figure it out from the report.  The dump of
shadow memory allows to identify the end of allocated memory, and
thereby the exact allocation size.

Link: http://lkml.kernel.org/r/1470062715-14077-4-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
f7376aed6c mm/kasan, slub: don't disable interrupts when object leaves quarantine
SLUB doesn't require disabled interrupts to call ___cache_free().

Link: http://lkml.kernel.org/r/1470062715-14077-3-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
4b3ec5a3f4 mm/kasan: don't reduce quarantine in atomic contexts
Currently we call quarantine_reduce() for ___GFP_KSWAPD_RECLAIM (implied
by __GFP_RECLAIM) allocation.  So, basically we call it on almost every
allocation.  quarantine_reduce() sometimes is heavy operation, and
calling it with disabled interrupts may trigger hard LOCKUP:

 NMI watchdog: Watchdog detected hard LOCKUP on cpu 2irq event stamp: 1411258
 Call Trace:
  <NMI>   dump_stack+0x68/0x96
   watchdog_overflow_callback+0x15b/0x190
   __perf_event_overflow+0x1b1/0x540
   perf_event_overflow+0x14/0x20
   intel_pmu_handle_irq+0x36a/0xad0
   perf_event_nmi_handler+0x2c/0x50
   nmi_handle+0x128/0x480
   default_do_nmi+0xb2/0x210
   do_nmi+0x1aa/0x220
   end_repeat_nmi+0x1a/0x1e
  <<EOE>>   __kernel_text_address+0x86/0xb0
   print_context_stack+0x7b/0x100
   dump_trace+0x12b/0x350
   save_stack_trace+0x2b/0x50
   set_track+0x83/0x140
   free_debug_processing+0x1aa/0x420
   __slab_free+0x1d6/0x2e0
   ___cache_free+0xb6/0xd0
   qlist_free_all+0x83/0x100
   quarantine_reduce+0x177/0x1b0
   kasan_kmalloc+0xf3/0x100

Reduce the quarantine_reduce iff direct reclaim is allowed.

Fixes: 55834c59098d("mm: kasan: initial memory quarantine implementation")
Link: http://lkml.kernel.org/r/1470062715-14077-2-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Andrey Ryabinin
4a3d308d66 mm/kasan: fix corruptions and false positive reports
Once an object is put into quarantine, we no longer own it, i.e.  object
could leave the quarantine and be reallocated.  So having set_track()
call after the quarantine_put() may corrupt slab objects.

 BUG kmalloc-4096 (Not tainted): Poison overwritten
 -----------------------------------------------------------------------------
 Disabling lock debugging due to kernel taint
 INFO: 0xffff8804540de850-0xffff8804540de857. First byte 0xb5 instead of 0x6b
...
 INFO: Freed in qlist_free_all+0x42/0x100 age=75 cpu=3 pid=24492
  __slab_free+0x1d6/0x2e0
  ___cache_free+0xb6/0xd0
  qlist_free_all+0x83/0x100
  quarantine_reduce+0x177/0x1b0
  kasan_kmalloc+0xf3/0x100
  kasan_slab_alloc+0x12/0x20
  kmem_cache_alloc+0x109/0x3e0
  mmap_region+0x53e/0xe40
  do_mmap+0x70f/0xa50
  vm_mmap_pgoff+0x147/0x1b0
  SyS_mmap_pgoff+0x2c7/0x5b0
  SyS_mmap+0x1b/0x30
  do_syscall_64+0x1a0/0x4e0
  return_from_SYSCALL_64+0x0/0x7a
 INFO: Slab 0xffffea0011503600 objects=7 used=7 fp=0x          (null) flags=0x8000000000004080
 INFO: Object 0xffff8804540de848 @offset=26696 fp=0xffff8804540dc588
 Redzone ffff8804540de840: bb bb bb bb bb bb bb bb                          ........
 Object ffff8804540de848: 6b 6b 6b 6b 6b 6b 6b 6b b5 52 00 00 f2 01 60 cc  kkkkkkkk.R....`.

Similarly, poisoning after the quarantine_put() leads to false positive
use-after-free reports:

 BUG: KASAN: use-after-free in anon_vma_interval_tree_insert+0x304/0x430 at addr ffff880405c540a0
 Read of size 8 by task trinity-c0/3036
 CPU: 0 PID: 3036 Comm: trinity-c0 Not tainted 4.7.0-think+ #9
 Call Trace:
   dump_stack+0x68/0x96
   kasan_report_error+0x222/0x600
   __asan_report_load8_noabort+0x61/0x70
   anon_vma_interval_tree_insert+0x304/0x430
   anon_vma_chain_link+0x91/0xd0
   anon_vma_clone+0x136/0x3f0
   anon_vma_fork+0x81/0x4c0
   copy_process.part.47+0x2c43/0x5b20
   _do_fork+0x16d/0xbd0
   SyS_clone+0x19/0x20
   do_syscall_64+0x1a0/0x4e0
   entry_SYSCALL64_slow_path+0x25/0x25

Fix this by putting an object in the quarantine after all other
operations.

Fixes: 80a9201a59 ("mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB")
Link: http://lkml.kernel.org/r/1470062715-14077-1-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Reported-by: Sasha Levin <alexander.levin@verizon.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Michal Hocko
d6507ff533 memcg: put soft limit reclaim out of way if the excess tree is empty
We've had a report about soft lockups caused by lock bouncing in the
soft reclaim path:

  BUG: soft lockup - CPU#0 stuck for 22s! [kav4proxy-kavic:3128]
  RIP: 0010:[<ffffffff81469798>]  [<ffffffff81469798>] _raw_spin_lock+0x18/0x20
  Call Trace:
    mem_cgroup_soft_limit_reclaim+0x25a/0x280
    shrink_zones+0xed/0x200
    do_try_to_free_pages+0x74/0x320
    try_to_free_pages+0x112/0x180
    __alloc_pages_slowpath+0x3ff/0x820
    __alloc_pages_nodemask+0x1e9/0x200
    alloc_pages_vma+0xe1/0x290
    do_wp_page+0x19f/0x840
    handle_pte_fault+0x1cd/0x230
    do_page_fault+0x1fd/0x4c0
    page_fault+0x25/0x30

There are no memcgs created so there cannot be any in the soft limit
excess obviously:

  [...]
  memory  0       1       1

so all this just seems to be mem_cgroup_largest_soft_limit_node trying
to get spin_lock_irq(&mctz->lock) just to find out that the soft limit
excess tree is empty.  This is just pointless wasting of cycles and
cache line bouncing during heavy parallel reclaim on large machines.
The particular machine wasn't very healthy and most probably suffering
from a memory leak which just caused the memory reclaim to trash
heavily.  But bouncing on the lock certainly didn't help...

Fix this by optimistic lockless check and bail out early if the tree is
empty.  This is theoretically racy but that shouldn't matter all that
much.  First of all soft limit is a best effort feature and it is slowly
getting deprecated and its usage should be really scarce.  Bouncing on a
lock without a good reason is surely much bigger problem, especially on
large CPU machines.

Link: http://lkml.kernel.org/r/1470073277-1056-1-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Michal Hocko
4e666314d2 mm, hugetlb: fix huge_pte_alloc BUG_ON
Zhong Jiang has reported a BUG_ON from huge_pte_alloc hitting when he
runs his database load with memory online and offline running in
parallel.  The reason is that huge_pmd_share might detect a shared pmd
which is currently migrated and so it has migration pte which is
!pte_huge.

There doesn't seem to be any easy way to prevent from the race and in
fact seeing the migration swap entry is not harmful.  Both callers of
huge_pte_alloc are prepared to handle them.  copy_hugetlb_page_range
will copy the swap entry and make it COW if needed.  hugetlb_fault will
back off and so the page fault is retries if the page is still under
migration and waits for its completion in hugetlb_fault.

That means that the BUG_ON is wrong and we should update it.  Let's
simply check that all present ptes are pte_huge instead.

Link: http://lkml.kernel.org/r/20160721074340.GA26398@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: zhongjiang <zhongjiang@huawei.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Jia He
649920c6ab mm/hugetlb: avoid soft lockup in set_max_huge_pages()
In powerpc servers with large memory(32TB), we watched several soft
lockups for hugepage under stress tests.

The call traces are as follows:
1.
get_page_from_freelist+0x2d8/0xd50
__alloc_pages_nodemask+0x180/0xc20
alloc_fresh_huge_page+0xb0/0x190
set_max_huge_pages+0x164/0x3b0

2.
prep_new_huge_page+0x5c/0x100
alloc_fresh_huge_page+0xc8/0x190
set_max_huge_pages+0x164/0x3b0

This patch fixes such soft lockups.  It is safe to call cond_resched()
there because it is out of spin_lock/unlock section.

Link: http://lkml.kernel.org/r/1469674442-14848-1-git-send-email-hejianet@gmail.com
Signed-off-by: Jia He <hejianet@gmail.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Minchan Kim
1a8018fb4c mm: move swap-in anonymous page into active list
Every swap-in anonymous page starts from inactive lru list's head.  It
should be activated unconditionally when VM decide to reclaim because
page table entry for the page always usually has marked accessed bit.
Thus, their window size for getting a new referece is 2 * NR_inactive +
NR_active while others is NR_inactive + NR_active.

It's not fair that it has more chance to be referenced compared to other
newly allocated page which starts from active lru list's head.

Johannes:

: The page can still have a valid copy on the swap device, so prefering to
: reclaim that page over a fresh one could make sense.  But as you point
: out, having it start inactive instead of active actually ends up giving it
: *more* LRU time, and that seems to be without justification.

Rik:

: The reason newly read in swap cache pages start on the inactive list is
: that we do some amount of read-around, and do not know which pages will
: get used.
:
: However, immediately activating the ones that DO get used, like your patch
: does, is the right thing to do.

Link: http://lkml.kernel.org/r/1469762740-17860-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Vegard Nossum
c5f88bd29a mm: fail prefaulting if page table allocation fails
I ran into this:

    BUG: sleeping function called from invalid context at mm/page_alloc.c:3784
    in_atomic(): 0, irqs_disabled(): 0, pid: 1434, name: trinity-c1
    2 locks held by trinity-c1/1434:
     #0:  (&mm->mmap_sem){......}, at: [<ffffffff810ce31e>] __do_page_fault+0x1ce/0x8f0
     #1:  (rcu_read_lock){......}, at: [<ffffffff81378f86>] filemap_map_pages+0xd6/0xdd0

    CPU: 0 PID: 1434 Comm: trinity-c1 Not tainted 4.7.0+ #58
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
    Call Trace:
      dump_stack+0x65/0x84
      panic+0x185/0x2dd
      ___might_sleep+0x51c/0x600
      __might_sleep+0x90/0x1a0
      __alloc_pages_nodemask+0x5b1/0x2160
      alloc_pages_current+0xcc/0x370
      pte_alloc_one+0x12/0x90
      __pte_alloc+0x1d/0x200
      alloc_set_pte+0xe3e/0x14a0
      filemap_map_pages+0x42b/0xdd0
      handle_mm_fault+0x17d5/0x28b0
      __do_page_fault+0x310/0x8f0
      trace_do_page_fault+0x18d/0x310
      do_async_page_fault+0x27/0xa0
      async_page_fault+0x28/0x30

The important bits from the above is that filemap_map_pages() is calling
into the page allocator while holding rcu_read_lock (sleeping is not
allowed inside RCU read-side critical sections).

According to Kirill Shutemov, the prefaulting code in do_fault_around()
is supposed to take care of this, but missing error handling means that
the allocation failure can go unnoticed.

We don't need to return VM_FAULT_OOM (or any other error) here, since we
can just let the normal fault path try again.

Fixes: 7267ec008b ("mm: postpone page table allocation until we have page to map")
Link: http://lkml.kernel.org/r/1469708107-11868-1-git-send-email-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Hillf Danton" <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 17:31:41 -04:00
Linus Torvalds
221bb8a46e - ARM: GICv3 ITS emulation and various fixes. Removal of the old
VGIC implementation.
 
 - s390: support for trapping software breakpoints, nested virtualization
 (vSIE), the STHYI opcode, initial extensions for CPU model support.
 
 - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups,
 preliminary to this and the upcoming support for hardware virtualization
 extensions.
 
 - x86: support for execute-only mappings in nested EPT; reduced vmexit
 latency for TSC deadline timer (by about 30%) on Intel hosts; support for
 more than 255 vCPUs.
 
 - PPC: bugfixes.
 
 The ugly bit is the conflicts.  A couple of them are simple conflicts due
 to 4.7 fixes, but most of them are with other trees. There was definitely
 too much reliance on Acked-by here.  Some conflicts are for KVM patches
 where _I_ gave my Acked-by, but the worst are for this pull request's
 patches that touch files outside arch/*/kvm.  KVM submaintainers should
 probably learn to synchronize better with arch maintainers, with the
 latter providing topic branches whenever possible instead of Acked-by.
 This is what we do with arch/x86.  And I should learn to refuse pull
 requests when linux-next sends scary signals, even if that means that
 submaintainers have to rebase their branches.
 
 Anyhow, here's the list:
 
 - arch/x86/kvm/vmx.c: handle_pcommit and EXIT_REASON_PCOMMIT was removed
 by the nvdimm tree.  This tree adds handle_preemption_timer and
 EXIT_REASON_PREEMPTION_TIMER at the same place.  In general all mentions
 of pcommit have to go.
 
 There is also a conflict between a stable fix and this patch, where the
 stable fix removed the vmx_create_pml_buffer function and its call.
 
 - virt/kvm/kvm_main.c: kvm_cpu_notifier was removed by the hotplug tree.
 This tree adds kvm_io_bus_get_dev at the same place.
 
 - virt/kvm/arm/vgic.c: a few final bugfixes went into 4.7 before the
 file was completely removed for 4.8.
 
 - include/linux/irqchip/arm-gic-v3.h: this one is entirely our fault;
 this is a change that should have gone in through the irqchip tree and
 pulled by kvm-arm.  I think I would have rejected this kvm-arm pull
 request.  The KVM version is the right one, except that it lacks
 GITS_BASER_PAGES_SHIFT.
 
 - arch/powerpc: what a mess.  For the idle_book3s.S conflict, the KVM
 tree is the right one; everything else is trivial.  In this case I am
 not quite sure what went wrong.  The commit that is causing the mess
 (fd7bacbca4, "KVM: PPC: Book3S HV: Fix TB corruption in guest exit
 path on HMI interrupt", 2016-05-15) touches both arch/powerpc/kernel/
 and arch/powerpc/kvm/.  It's large, but at 396 insertions/5 deletions
 I guessed that it wasn't really possible to split it and that the 5
 deletions wouldn't conflict.  That wasn't the case.
 
 - arch/s390: also messy.  First is hypfs_diag.c where the KVM tree
 moved some code and the s390 tree patched it.  You have to reapply the
 relevant part of commits 6c22c98637, plus all of e030c1125e, to
 arch/s390/kernel/diag.c.  Or pick the linux-next conflict
 resolution from http://marc.info/?l=kvm&m=146717549531603&w=2.
 Second, there is a conflict in gmap.c between a stable fix and 4.8.
 The KVM version here is the correct one.
 
 I have pushed my resolution at refs/heads/merge-20160802 (commit
 3d1f53419842) at git://git.kernel.org/pub/scm/virt/kvm/kvm.git.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:

 - ARM: GICv3 ITS emulation and various fixes.  Removal of the
   old VGIC implementation.

 - s390: support for trapping software breakpoints, nested
   virtualization (vSIE), the STHYI opcode, initial extensions
   for CPU model support.

 - MIPS: support for MIPS64 hosts (32-bit guests only) and lots
   of cleanups, preliminary to this and the upcoming support for
   hardware virtualization extensions.

 - x86: support for execute-only mappings in nested EPT; reduced
   vmexit latency for TSC deadline timer (by about 30%) on Intel
   hosts; support for more than 255 vCPUs.

 - PPC: bugfixes.

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits)
  KVM: PPC: Introduce KVM_CAP_PPC_HTM
  MIPS: Select HAVE_KVM for MIPS64_R{2,6}
  MIPS: KVM: Reset CP0_PageMask during host TLB flush
  MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX()
  MIPS: KVM: Sign extend MFC0/RDHWR results
  MIPS: KVM: Fix 64-bit big endian dynamic translation
  MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase
  MIPS: KVM: Use 64-bit CP0_EBase when appropriate
  MIPS: KVM: Set CP0_Status.KX on MIPS64
  MIPS: KVM: Make entry code MIPS64 friendly
  MIPS: KVM: Use kmap instead of CKSEG0ADDR()
  MIPS: KVM: Use virt_to_phys() to get commpage PFN
  MIPS: Fix definition of KSEGX() for 64-bit
  KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD
  kvm: x86: nVMX: maintain internal copy of current VMCS
  KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE
  KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures
  KVM: arm64: vgic-its: Simplify MAPI error handling
  KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers
  KVM: arm64: vgic-its: Turn device_id validation into generic ID validation
  ...
2016-08-02 16:11:27 -04:00
Aneesh Kumar K.V
5491ae7b6f powerpc/mm/hugetlb: Add flush_hugetlb_tlb_range
Some archs like ppc64 need to do special things when flushing tlb for
hugepage. Add a new helper to flush hugetlb tlb range. This helps us to
avoid flushing the entire tlb mapping for the pid.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-01 11:15:13 +10:00
Linus Torvalds
27ae0c41ed Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
 "This fixes error propagation from writeback to fsync/close for
  writeback cache mode as well as adding a missing capability flag to
  the INIT message.  The rest are cleanups.

  (The commits are recent but all the code actually sat in -next for a
  while now.  The recommits are due to conflict avoidance and the
  addition of Cc: stable@...)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: use filemap_check_errors()
  mm: export filemap_check_errors() to modules
  fuse: fix wrong assignment of ->flags in fuse_send_init()
  fuse: fuse_flush must check mapping->flags for errors
  fuse: fsync() did not return IO errors
  fuse: don't mess with blocking signals
  new helper: wait_event_killable_exclusive()
  fuse: improve aio directIO write performance for size extending writes
2016-07-29 12:29:15 -07:00
Miklos Szeredi
d72d9e2a5d mm: export filemap_check_errors() to modules
Can be used by fuse, btrfs and f2fs to replace opencoded variants.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29 14:10:57 +02:00
Linus Torvalds
1c88e19b0f Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "The rest of MM"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (101 commits)
  mm, compaction: simplify contended compaction handling
  mm, compaction: introduce direct compaction priority
  mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations
  mm, page_alloc: make THP-specific decisions more generic
  mm, page_alloc: restructure direct compaction handling in slowpath
  mm, page_alloc: don't retry initial attempt in slowpath
  mm, page_alloc: set alloc_flags only once in slowpath
  lib/stackdepot.c: use __GFP_NOWARN for stack allocations
  mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB
  mm, kasan: account for object redzone in SLUB's nearest_obj()
  mm: fix use-after-free if memory allocation failed in vma_adjust()
  zsmalloc: Delete an unnecessary check before the function call "iput"
  mm/memblock.c: fix index adjustment error in __next_mem_range_rev()
  mem-hotplug: alloc new page from a nearest neighbor node when mem-offline
  mm: optimize copy_page_to/from_iter_iovec
  mm: add cond_resched() to generic_swapfile_activate()
  Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"
  mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT mode
  mm: hwpoison: remove incorrect comments
  make __section_nr() more efficient
  ...
2016-07-28 16:36:48 -07:00
Vlastimil Babka
c3486f5376 mm, compaction: simplify contended compaction handling
Async compaction detects contention either due to failing trylock on
zone->lock or lru_lock, or by need_resched().  Since 1f9efdef4f ("mm,
compaction: khugepaged should not give up due to need_resched()") the
code got quite complicated to distinguish these two up to the
__alloc_pages_slowpath() level, so different decisions could be taken
for khugepaged allocations.

After the recent changes, khugepaged allocations don't check for
contended compaction anymore, so we again don't need to distinguish lock
and sched contention, and simplify the current convoluted code a lot.

However, I believe it's also possible to simplify even more and
completely remove the check for contended compaction after the initial
async compaction for costly orders, which was originally aimed at THP
page fault allocations.  There are several reasons why this can be done
now:

- with the new defaults, THP page faults no longer do reclaim/compaction at
  all, unless the system admin has overridden the default, or application has
  indicated via madvise that it can benefit from THP's. In both cases, it
  means that the potential extra latency is expected and worth the benefits.
- even if reclaim/compaction proceeds after this patch where it previously
  wouldn't, the second compaction attempt is still async and will detect the
  contention and back off, if the contention persists
- there are still heuristics like deferred compaction and pageblock skip bits
  in place that prevent excessive THP page fault latencies

Link: http://lkml.kernel.org/r/20160721073614.24395-9-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Vlastimil Babka
a5508cd83f mm, compaction: introduce direct compaction priority
In the context of direct compaction, for some types of allocations we
would like the compaction to either succeed or definitely fail while
trying as hard as possible.  Current async/sync_light migration mode is
insufficient, as there are heuristics such as caching scanner positions,
marking pageblocks as unsuitable or deferring compaction for a zone.  At
least the final compaction attempt should be able to override these
heuristics.

To communicate how hard compaction should try, we replace migration mode
with a new enum compact_priority and change the relevant function
signatures.  In compact_zone_order() where struct compact_control is
constructed, the priority is mapped to suitable control flags.  This
patch itself has no functional change, as the current priority levels
are mapped back to the same migration modes as before.  Expanding them
will be done next.

Note that !CONFIG_COMPACTION variant of try_to_compact_pages() is
removed, as the only caller exists under CONFIG_COMPACTION.

Link: http://lkml.kernel.org/r/20160721073614.24395-8-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Vlastimil Babka
2516035499 mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations
After the previous patch, we can distinguish costly allocations that
should be really lightweight, such as THP page faults, with
__GFP_NORETRY.  This means we don't need to recognize khugepaged
allocations via PF_KTHREAD anymore.  We can also change THP page faults
in areas where madvise(MADV_HUGEPAGE) was used to try as hard as
khugepaged, as the process has indicated that it benefits from THP's and
is willing to pay some initial latency costs.

We can also make the flags handling less cryptic by distinguishing
GFP_TRANSHUGE_LIGHT (no reclaim at all, default mode in page fault) from
GFP_TRANSHUGE (only direct reclaim, khugepaged default).  Adding
__GFP_NORETRY or __GFP_KSWAPD_RECLAIM is done where needed.

The patch effectively changes the current GFP_TRANSHUGE users as
follows:

* get_huge_zero_page() - the zero page lifetime should be relatively
  long and it's shared by multiple users, so it's worth spending some
  effort on it.  We use GFP_TRANSHUGE, and __GFP_NORETRY is not added.
  This also restores direct reclaim to this allocation, which was
  unintentionally removed by commit e4a49efe4e7e ("mm: thp: set THP defrag
  by default to madvise and add a stall-free defrag option")

* alloc_hugepage_khugepaged_gfpmask() - this is khugepaged, so latency
  is not an issue.  So if khugepaged "defrag" is enabled (the default), do
  reclaim via GFP_TRANSHUGE without __GFP_NORETRY.  We can remove the
  PF_KTHREAD check from page alloc.

  As a side-effect, khugepaged will now no longer check if the initial
  compaction was deferred or contended.  This is OK, as khugepaged sleep
  times between collapsion attempts are long enough to prevent noticeable
  disruption, so we should allow it to spend some effort.

* migrate_misplaced_transhuge_page() - already was masking out
  __GFP_RECLAIM, so just convert to GFP_TRANSHUGE_LIGHT which is
  equivalent.

* alloc_hugepage_direct_gfpmask() - vma's with VM_HUGEPAGE (via madvise)
  are now allocating without __GFP_NORETRY.  Other vma's keep using
  __GFP_NORETRY if direct reclaim/compaction is at all allowed (by default
  it's allowed only for madvised vma's).  The rest is conversion to
  GFP_TRANSHUGE(_LIGHT).

[mhocko@suse.com: suggested GFP_TRANSHUGE_LIGHT]
Link: http://lkml.kernel.org/r/20160721073614.24395-7-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Vlastimil Babka
3eb2771b06 mm, page_alloc: make THP-specific decisions more generic
Since THP allocations during page faults can be costly, extra decisions
are employed for them to avoid excessive reclaim and compaction, if the
initial compaction doesn't look promising.  The detection has never been
perfect as there is no gfp flag specific to THP allocations.  At this
moment it checks the whole combination of flags that makes up
GFP_TRANSHUGE, and hopes that no other users of such combination exist,
or would mind being treated the same way.  Extra care is also taken to
separate allocations from khugepaged, where latency doesn't matter that
much.

It is however possible to distinguish these allocations in a simpler and
more reliable way.  The key observation is that after the initial
compaction followed by the first iteration of "standard"
reclaim/compaction, both __GFP_NORETRY allocations and costly
allocations without __GFP_REPEAT are declared as failures:

        /* Do not loop if specifically requested */
        if (gfp_mask & __GFP_NORETRY)
                goto nopage;

        /*
         * Do not retry costly high order allocations unless they are
         * __GFP_REPEAT
         */
        if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT))
                goto nopage;

This means we can further distinguish allocations that are costly order
*and* additionally include the __GFP_NORETRY flag.  As it happens,
GFP_TRANSHUGE allocations do already fall into this category.  This will
also allow other costly allocations with similar high-order benefit vs
latency considerations to use this semantic.  Furthermore, we can
distinguish THP allocations that should try a bit harder (such as from
khugepageed) by removing __GFP_NORETRY, as will be done in the next
patch.

Link: http://lkml.kernel.org/r/20160721073614.24395-6-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Vlastimil Babka
a8161d1ed6 mm, page_alloc: restructure direct compaction handling in slowpath
The retry loop in __alloc_pages_slowpath is supposed to keep trying
reclaim and compaction (and OOM), until either the allocation succeeds,
or returns with failure.  Success here is more probable when reclaim
precedes compaction, as certain watermarks have to be met for compaction
to even try, and more free pages increase the probability of compaction
success.  On the other hand, starting with light async compaction (if
the watermarks allow it), can be more efficient, especially for smaller
orders, if there's enough free memory which is just fragmented.

Thus, the current code starts with compaction before reclaim, and to
make sure that the last reclaim is always followed by a final
compaction, there's another direct compaction call at the end of the
loop.  This makes the code hard to follow and adds some duplicated
handling of migration_mode decisions.  It's also somewhat inefficient
that even if reclaim or compaction decides not to retry, the final
compaction is still attempted.  Some gfp flags combination also shortcut
these retry decisions by "goto noretry;", making it even harder to
follow.

This patch attempts to restructure the code with only minimal functional
changes.  The call to the first compaction and THP-specific checks are
now placed above the retry loop, and the "noretry" direct compaction is
removed.

The initial compaction is additionally restricted only to costly orders,
as we can expect smaller orders to be held back by watermarks, and only
larger orders to suffer primarily from fragmentation.  This better
matches the checks in reclaim's shrink_zones().

There are two other smaller functional changes.  One is that the upgrade
from async migration to light sync migration will always occur after the
initial compaction.  This is how it has been until recent patch "mm,
oom: protect !costly allocations some more", which introduced upgrading
the mode based on COMPACT_COMPLETE result, but kept the final compaction
always upgraded, which made it even more special.  It's better to return
to the simpler handling for now, as migration modes will be further
modified later in the series.

The second change is that once both reclaim and compaction declare it's
not worth to retry the reclaim/compact loop, there is no final
compaction attempt.  As argued above, this is intentional.  If that
final compaction were to succeed, it would be due to a wrong retry
decision, or simply a race with somebody else freeing memory for us.

The main outcome of this patch should be simpler code.  Logically, the
initial compaction without reclaim is the exceptional case to the
reclaim/compaction scheme, but prior to the patch, it was the last loop
iteration that was exceptional.  Now the code matches the logic better.
The change also enable the following patches.

Link: http://lkml.kernel.org/r/20160721073614.24395-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Vlastimil Babka
23771235bb mm, page_alloc: don't retry initial attempt in slowpath
After __alloc_pages_slowpath() sets up new alloc_flags and wakes up
kswapd, it first tries get_page_from_freelist() with the new
alloc_flags, as it may succeed e.g. due to using min watermark instead
of low watermark.  It makes sense to to do this attempt before adjusting
zonelist based on alloc_flags/gfp_mask, as it's still relatively a fast
path if we just wake up kswapd and successfully allocate.

This patch therefore moves the initial attempt above the retry label and
reorganizes a bit the part below the retry label.  We still have to
attempt get_page_from_freelist() on each retry, as some allocations
cannot do that as part of direct reclaim or compaction, and yet are not
allowed to fail (even though they do a WARN_ON_ONCE() and thus should
not exist).  We can reuse the call meant for ALLOC_NO_WATERMARKS attempt
and just set alloc_flags to ALLOC_NO_WATERMARKS if the context allows
it.  As a side-effect, the attempts from direct reclaim/compaction will
also no longer obey watermarks once this is set, but there's little harm
in that.

Kswapd wakeups are also done on each retry to be safe from potential
races resulting in kswapd going to sleep while a process (that may not
be able to reclaim by itself) is still looping.

Link: http://lkml.kernel.org/r/20160721073614.24395-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Vlastimil Babka
31a6c1909f mm, page_alloc: set alloc_flags only once in slowpath
In __alloc_pages_slowpath(), alloc_flags doesn't change after it's
initialized, so move the initialization above the retry: label.  Also
make the comment above the initialization more descriptive.

The only exception in the alloc_flags being constant is
ALLOC_NO_WATERMARKS, which may change due to TIF_MEMDIE being set on the
allocating thread.  We can fix this, and make the code simpler and a bit
more effective at the same time, by moving the part that determines
ALLOC_NO_WATERMARKS from gfp_to_alloc_flags() to gfp_pfmemalloc_allowed().

This means we don't have to mask out ALLOC_NO_WATERMARKS in numerous
places in __alloc_pages_slowpath() anymore.  The only two tests for the
flag can instead call gfp_pfmemalloc_allowed().

Link: http://lkml.kernel.org/r/20160721073614.24395-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Alexander Potapenko
80a9201a59 mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB
For KASAN builds:
 - switch SLUB allocator to using stackdepot instead of storing the
   allocation/deallocation stacks in the objects;
 - change the freelist hook so that parts of the freelist can be put
   into the quarantine.

[aryabinin@virtuozzo.com: fixes]
  Link: http://lkml.kernel.org/r/1468601423-28676-1-git-send-email-aryabinin@virtuozzo.com
Link: http://lkml.kernel.org/r/1468347165-41906-3-git-send-email-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Alexander Potapenko
c146a2b98e mm, kasan: account for object redzone in SLUB's nearest_obj()
When looking up the nearest SLUB object for a given address, correctly
calculate its offset if SLAB_RED_ZONE is enabled for that cache.

Previously, when KASAN had detected an error on an object from a cache
with SLAB_RED_ZONE set, the actual start address of the object was
miscalculated, which led to random stacks having been reported.

When looking up the nearest SLUB object for a given address, correctly
calculate its offset if SLAB_RED_ZONE is enabled for that cache.

Fixes: 7ed2f9e663 ("mm, kasan: SLAB support")
Link: http://lkml.kernel.org/r/1468347165-41906-2-git-send-email-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Kirill A. Shutemov
734537c9cb mm: fix use-after-free if memory allocation failed in vma_adjust()
There's one case when vma_adjust() expands the vma, overlapping with
*two* next vma.  See case 6 of mprotect, described in the comment to
vma_merge().

To handle this (and only this) situation we iterate twice over main part
of the function.  See "goto again".

Vegard reported[1] that he sees out-of-bounds access complain from
KASAN, if anon_vma_clone() on the *second* iteration fails.

This happens because we free 'next' vma by the end of first iteration
and don't have a way to undo this if anon_vma_clone() fails on the
second iteration.

The solution is to do all required allocations upfront, before we touch
vmas.

The allocation on the second iteration is only required if first two
vmas don't have anon_vma, but third does.  So we need, in total, one
anon_vma_clone() call.

It's easy to adjust 'exporter' to the third vma for such case.

[1] http://lkml.kernel.org/r/1469514843-23778-1-git-send-email-vegard.nossum@oracle.com

Link: http://lkml.kernel.org/r/1469625255-126641-1-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Markus Elfring
c3491eca37 zsmalloc: Delete an unnecessary check before the function call "iput"
iput() tests whether its argument is NULL and then returns immediately.
Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/559cf499-4a01-25f9-c87f-24d906626a57@users.sourceforge.net
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
zijun_hu
fb399b4854 mm/memblock.c: fix index adjustment error in __next_mem_range_rev()
Fix region index adjustment error when parameter type_b of
__next_mem_range_rev() == NULL.

Signed-off-by: zijun_hu <zijun_hu@htc.com>
Cc: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Wei Yang <weiyang@linux.vnet.ibm.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Richard Leitner <dev@g0hl1n.net>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Xishi Qiu
394e31d2ce mem-hotplug: alloc new page from a nearest neighbor node when mem-offline
If we offline a node, alloc the new page from a nearest neighbor node
instead of the current node or other remote nodes, because re-migrate is
a waste of time and the distance of the remote nodes is often very
large.

Also use GFP_HIGHUSER_MOVABLE to alloc new page if the zone is movable
zone or highmem zone.

Link: http://lkml.kernel.org/r/5795E18B.5060302@huawei.com
Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mikulas Patocka
7e4411bfe6 mm: add cond_resched() to generic_swapfile_activate()
generic_swapfile_activate() can take quite long time, it iterates over
all blocks of a file, so add cond_resched to it.  I observed about 1
second stalls when activating a swapfile that was almost unfragmented -
this patch fixes it.

Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1607221710580.4818@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Michal Hocko
4e390b2b2f Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"
This reverts commit f9054c70d2 ("mm, mempool: only set __GFP_NOMEMALLOC
if there are free elements").

There has been a report about OOM killer invoked when swapping out to a
dm-crypt device.  The primary reason seems to be that the swapout out IO
managed to completely deplete memory reserves.  Ondrej was able to
bisect and explained the issue by pointing to f9054c70d2 ("mm,
mempool: only set __GFP_NOMEMALLOC if there are free elements").

The reason is that the swapout path is not throttled properly because
the md-raid layer needs to allocate from the generic_make_request path
which means it allocates from the PF_MEMALLOC context.  dm layer uses
mempool_alloc in order to guarantee a forward progress which used to
inhibit access to memory reserves when using page allocator.  This has
changed by f9054c70d2 ("mm, mempool: only set __GFP_NOMEMALLOC if
there are free elements") which has dropped the __GFP_NOMEMALLOC
protection when the memory pool is depleted.

If we are running out of memory and the only way forward to free memory
is to perform swapout we just keep consuming memory reserves rather than
throttling the mempool allocations and allowing the pending IO to
complete up to a moment when the memory is depleted completely and there
is no way forward but invoking the OOM killer.  This is less than
optimal.

The original intention of f9054c70d2 was to help with the OOM
situations where the oom victim depends on mempool allocation to make a
forward progress.  David has mentioned the following backtrace:

  schedule
  schedule_timeout
  io_schedule_timeout
  mempool_alloc
  __split_and_process_bio
  dm_request
  generic_make_request
  submit_bio
  mpage_readpages
  ext4_readpages
  __do_page_cache_readahead
  ra_submit
  filemap_fault
  handle_mm_fault
  __do_page_fault
  do_page_fault
  page_fault

We do not know more about why the mempool is depleted without being
replenished in time, though.  In any case the dm layer shouldn't depend
on any allocations outside of the dedicated pools so a forward progress
should be guaranteed.  If this is not the case then the dm should be
fixed rather than papering over the problem and postponing it to later
by accessing more memory reserves.

mempools are a mechanism to maintain dedicated memory reserves to
guaratee forward progress.  Allowing them an unbounded access to the
page allocator memory reserves is going against the whole purpose of
this mechanism.

Bisected by Ondrej Kozina.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20160721145309.GR26379@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: NeilBrown <neilb@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Mel Gorman <mgorman@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Hugh Dickins
1d2047fefa mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT mode
At present MIGRATE_SYNC_LIGHT is allowing __isolate_lru_page() to
isolate a PageWriteback page, which __unmap_and_move() then rejects with
-EBUSY: of course the writeback might complete in between, but that's
not what we usually expect, so probably better not to isolate it.

When tested by stress-highalloc from mmtests, this has reduced the
number of page migrate failures by 60-70%.

Link: http://lkml.kernel.org/r/20160721073614.24395-2-vbabka@suse.cz
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Naoya Horiguchi
7c7fd82556 mm: hwpoison: remove incorrect comments
dequeue_hwpoisoned_huge_page() can be called without page lock hold, so
let's remove incorrect comment.

The reason why the page lock is not really needed is that
dequeue_hwpoisoned_huge_page() checks page_huge_active() inside
hugetlb_lock, which allows us to avoid trying to dequeue a hugepage that
are just allocated but not linked to active list yet, even without
taking page lock.

Link: http://lkml.kernel.org/r/20160720092901.GA15995@www9186uo.sakura.ne.jp
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Zhan Chen <zhanc1@andrew.cmu.edu>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Zhou Chengming
91fd8b95d6 make __section_nr() more efficient
When CONFIG_SPARSEMEM_EXTREME is disabled, __section_nr can get the
section number with a subtraction directly.

Link: http://lkml.kernel.org/r/1468988310-11560-1-git-send-email-zhouchengming1@huawei.com
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Vegard Nossum
98c42d9452 kmemleak: don't hang if user disables scanning early
If the user tries to disable automatic scanning early in the boot
process using e.g.:

  echo scan=off > /sys/kernel/debug/kmemleak

then this command will hang until SECS_FIRST_SCAN (= 60) seconds have
elapsed, even though the system is fully initialised.

We can fix this using interruptible sleep and checking if we're supposed
to stop whenever we wake up (like the rest of the code does).

Link: http://lkml.kernel.org/r/1468835005-2873-1-git-send-email-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Dennis Chen
a571d4eb55 mm/memblock.c: add new infrastructure to address the mem limit issue
In some cases, memblock is queried by kernel to determine whether a
specified address is RAM or not.  For example, the ACPI core needs this
information to determine which attributes to use when mapping ACPI
regions(acpi_os_ioremap).  Use of incorrect memory types can result in
faults, data corruption, or other issues.

Removing memory with memblock_enforce_memory_limit() throws away this
information, and so a kernel booted with 'mem=' may suffer from the
issues described above.  To avoid this, we need to keep those NOMAP
regions instead of removing all above the limit, which preserves the
information we need while preventing other use of those regions.

This patch adds new infrastructure to retain all NOMAP memblock regions
while removing others, to cater for this.

Link: http://lkml.kernel.org/r/1468475036-5852-2-git-send-email-dennis.chen@arm.com
Signed-off-by: Dennis Chen <dennis.chen@arm.com>
Acked-by: Steve Capper <steve.capper@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Kaly Xin <kaly.xin@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Andy Lutomirski
efdc949079 mm: fix memcg stack accounting for sub-page stacks
We should account for stacks regardless of stack size, and we need to
account in sub-page units if THREAD_SIZE < PAGE_SIZE.  Change the units
to kilobytes and Move it into account_kernel_stack().

Fixes: 12580e4b54 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat")
Link: http://lkml.kernel.org/r/9b5314e3ee5eda61b0317ec1563768602c1ef438.1468523549.git.luto@kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Andy Lutomirski
d30dd8be06 mm: track NR_KERNEL_STACK in KiB instead of number of stacks
Currently, NR_KERNEL_STACK tracks the number of kernel stacks in a zone.
This only makes sense if each kernel stack exists entirely in one zone,
and allowing vmapped stacks could break this assumption.

Since frv has THREAD_SIZE < PAGE_SIZE, we need to track kernel stack
allocations in a unit that divides both THREAD_SIZE and PAGE_SIZE on all
architectures.  Keep it simple and use KiB.

Link: http://lkml.kernel.org/r/083c71e642c5fa5f1b6898902e1b2db7b48940d4.1468523549.git.luto@kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Dan Williams
c02b6aec6d mm: CONFIG_ZONE_DEVICE stop depending on CONFIG_EXPERT
When it was first introduced CONFIG_ZONE_DEVICE depended on disabling
CONFIG_ZONE_DMA, a configuration choice reserved for "experts".
However, now that the ZONE_DMA conflict has been eliminated it no longer
makes sense to require CONFIG_EXPERT.

Link: http://lkml.kernel.org/r/146687646274.39261.14267596518720371009.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Eric Sandeen <sandeen@redhat.com>
Reported-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Christoph Hellwig
c4c5ad6b35 memblock: include <asm/sections.h> instead of <asm-generic/sections.h>
asm-generic headers are generic implementations for architecture
specific code and should not be included by common code.  Thus use the
asm/ version of sections.h to get at the linker sections.

Link: http://lkml.kernel.org/r/1468285103-7470-1-git-send-email-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Huang Ying
319904ad40 mm, THP: clean up return value of madvise_free_huge_pmd
The definition of return value of madvise_free_huge_pmd is not clear
before.  According to the suggestion of Minchan Kim, change the type of
return value to bool and return true if we do MADV_FREE successfully on
entire pmd page, otherwise, return false.  Comments are added too.

Link: http://lkml.kernel.org/r/1467135452-16688-2-git-send-email-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ganesh Mahendran
18fd06bf7a mm/zsmalloc: use helper to clear page->flags bit
Use ClearPagePrivate/ClearPagePrivate2 helpers to clear
PG_private/PG_private_2 in page->flags

Link: http://lkml.kernel.org/r/1467882338-4300-7-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ganesh Mahendran
35b3445e97 mm/zsmalloc: add __init,__exit attribute
Add __init,__exit attribute for function that only called in module
init/exit to save memory.

Link: http://lkml.kernel.org/r/1467882338-4300-6-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ganesh Mahendran
fd8544639e mm/zsmalloc: keep comments consistent with code
Some minor commebnt changes:

 1). update zs_malloc(),zs_create_pool() function header
 2). update "Usage of struct page fields"

Link: http://lkml.kernel.org/r/1467882338-4300-5-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ganesh Mahendran
64d90465f0 mm/zsmalloc: avoid calculate max objects of zspage twice
Currently, if a class can not be merged, the max objects of zspage in
that class may be calculated twice.

This patch calculate max objects of zspage at the begin, and pass the
value to can_merge() to decide whether the class can be merged.

Also this patch remove function get_maxobj_per_zspage(), as there is no
other place to call this function.

Link: http://lkml.kernel.org/r/1467882338-4300-4-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ganesh Mahendran
b4fd07a086 mm/zsmalloc: use class->objs_per_zspage to get num of max objects
num of max objects in zspage is stored in each size_class now.  So there
is no need to re-calculate it.

Link: http://lkml.kernel.org/r/1467882338-4300-3-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ganesh Mahendran
cf675acb74 mm/zsmalloc: take obj index back from find_alloced_obj
the obj index value should be updated after return from
find_alloced_obj() to avoid CPU burning caused by unnecessary object
scanning.

Link: http://lkml.kernel.org/r/1467882338-4300-2-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Ganesh Mahendran
41b88e14c1 mm/zsmalloc: use obj_index to keep consistent with others
This is a cleanup patch.  Change "index" to "obj_index" to keep
consistent with others in zsmalloc.

Link: http://lkml.kernel.org/r/1467882338-4300-1-git-send-email-opensource.ganesh@gmail.com
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Minchan Kim
91dcade47a mm: bail out in shrink_inactive_list()
With node-lru, if there are enough reclaimable pages in highmem but
nothing in lowmem, VM can try to shrink inactive list although the
requested zone is lowmem.

The problem is that if the inactive list is full of highmem pages then a
direct reclaimer searching for a lowmem page waste CPU scanning
uselessly.  It just burns out CPU.  Even, many direct reclaimers are
stalled by too_many_isolated if lots of parallel reclaimer are going on
although there are no reclaimable memory in inactive list.

I tried the experiment 4 times in 32bit 2G 8 CPU KVM machine to get
elapsed time.

	hackbench 500 process 2

 = Old =

  1st: 289s 2nd: 310s 3rd: 112s 4th: 272s

 = Now =

  1st: 31s  2nd: 132s 3rd: 162s 4th: 50s.

[akpm@linux-foundation.org: fixes per Mel]
Link: http://lkml.kernel.org/r/1469433119-1543-1-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
d7f05528ee mm, vmscan: account for skipped pages as a partial scan
Page reclaim determines whether a pgdat is unreclaimable by examining
how many pages have been scanned since a page was freed and comparing
that to the LRU sizes.  Skipped pages are not reclaim candidates but
contribute to scanned.  This can prematurely mark a pgdat as
unreclaimable and trigger an OOM kill.

This patch accounts for skipped pages as a partial scan so that an
unreclaimable pgdat will still be marked as such but by scaling the cost
of a skip, it'll avoid the pgdat being marked prematurely.

Link: http://lkml.kernel.org/r/1469110261-7365-6-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
f8d1a31163 mm: consider whether to decivate based on eligible zones inactive ratio
Minchan Kim reported that with per-zone lru state it was possible to
identify that a normal zone with 8^M anonymous pages could trigger OOM
with non-atomic order-0 allocations as all pages in the zone were in the
active list.

   gfp_mask=0x26004c0(GFP_KERNEL|__GFP_REPEAT|__GFP_NOTRACK), order=0
   Call Trace:
     __alloc_pages_nodemask+0xe52/0xe60
     ? new_slab+0x39c/0x3b0
     new_slab+0x39c/0x3b0
     ___slab_alloc.constprop.87+0x6da/0x840
     ? __alloc_skb+0x3c/0x260
     ? enqueue_task_fair+0x73/0xbf0
     ? poll_select_copy_remaining+0x140/0x140
     __slab_alloc.isra.81.constprop.86+0x40/0x6d
     ? __alloc_skb+0x3c/0x260
     kmem_cache_alloc+0x22c/0x260
     ? __alloc_skb+0x3c/0x260
     __alloc_skb+0x3c/0x260
     alloc_skb_with_frags+0x4e/0x1a0
     sock_alloc_send_pskb+0x16a/0x1b0
     ? wait_for_unix_gc+0x31/0x90
     unix_stream_sendmsg+0x28d/0x340
     sock_sendmsg+0x2d/0x40
     sock_write_iter+0x6c/0xc0
     __vfs_write+0xc0/0x120
     vfs_write+0x9b/0x1a0
     ? __might_fault+0x49/0xa0
     SyS_write+0x44/0x90
     do_fast_syscall_32+0xa6/0x1e0

   Mem-Info:
   active_anon:101103 inactive_anon:102219 isolated_anon:0
    active_file:503 inactive_file:544 isolated_file:0
    unevictable:0 dirty:0 writeback:34 unstable:0
    slab_reclaimable:6298 slab_unreclaimable:74669
    mapped:863 shmem:0 pagetables:100998 bounce:0
    free:23573 free_pcp:1861 free_cma:0
   Node 0 active_anon:404412kB inactive_anon:409040kB active_file:2012kB inactive_file:2176kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:3452kB dirty:0kB writeback:136kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:1320845 all_unreclaimable? yes
   DMA free:3296kB min:68kB low:84kB high:100kB active_anon:5540kB inactive_anon:0kB active_file:0kB inactive_file:0kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:248kB slab_unreclaimable:2628kB kernel_stack:792kB pagetables:2316kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
   lowmem_reserve[]: 0 809 1965 1965
   Normal free:3600kB min:3604kB low:4504kB high:5404kB active_anon:86304kB inactive_anon:0kB active_file:160kB inactive_file:376kB present:897016kB managed:858524kB mlocked:0kB slab_reclaimable:24944kB slab_unreclaimable:296048kB kernel_stack:163832kB pagetables:35892kB bounce:0kB free_pcp:3076kB local_pcp:656kB free_cma:0kB
   lowmem_reserve[]: 0 0 9247 9247
   HighMem free:86156kB min:512kB low:1796kB high:3080kB active_anon:312852kB inactive_anon:410024kB active_file:1924kB inactive_file:2012kB present:1183736kB managed:1183736kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:365784kB bounce:0kB free_pcp:3868kB local_pcp:720kB free_cma:0kB
   lowmem_reserve[]: 0 0 0 0
   DMA: 8*4kB (UM) 8*8kB (UM) 4*16kB (M) 2*32kB (UM) 2*64kB (UM) 1*128kB (M) 3*256kB (UME) 2*512kB (UE) 1*1024kB (E) 0*2048kB 0*4096kB = 3296kB
   Normal: 240*4kB (UME) 160*8kB (UME) 23*16kB (ME) 3*32kB (UE) 3*64kB (UME) 2*128kB (ME) 1*256kB (U) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3408kB
   HighMem: 10942*4kB (UM) 3102*8kB (UM) 866*16kB (UM) 76*32kB (UM) 11*64kB (UM) 4*128kB (UM) 1*256kB (M) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 86344kB
   Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
   54409 total pagecache pages
   53215 pages in swap cache
   Swap cache stats: add 300982, delete 247765, find 157978/226539
   Free swap  = 3803244kB
   Total swap = 4192252kB
   524186 pages RAM
   295934 pages HighMem/MovableOnly
   9642 pages reserved
   0 pages cma reserved

The problem is due to the active deactivation logic in
inactive_list_is_low:

	Node 0 active_anon:404412kB inactive_anon:409040kB

IOW, (inactive_anon of node * inactive_ratio > active_anon of node) due
to highmem anonymous stat so VM never deactivates normal zone's
anonymous pages.

This patch is a modified version of Minchan's original solution but
based upon it.  The problem with Minchan's patch is that any low zone
with an imbalanced list could force a rotation.

In this patch, a zone-constrained global reclaim will rotate the list if
the inactive/active ratio of all eligible zones needs to be corrected.
It is possible that higher zone pages will be initially rotated
prematurely but this is the safer choice to maintain overall LRU age.

Link: http://lkml.kernel.org/r/20160722090929.GJ10438@techsingularity.net
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
5a1c84b404 mm: remove reclaim and compaction retry approximations
If per-zone LRU accounting is available then there is no point
approximating whether reclaim and compaction should retry based on pgdat
statistics.  This is effectively a revert of "mm, vmstat: remove zone
and node double accounting by approximating retries" with the difference
that inactive/active stats are still available.  This preserves the
history of why the approximation was retried and why it had to be
reverted to handle OOM kills on 32-bit systems.

Link: http://lkml.kernel.org/r/1469110261-7365-4-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
bb4cc2bea6 mm, vmscan: remove highmem_file_pages
With the reintroduction of per-zone LRU stats, highmem_file_pages is
redundant so remove it.

[mgorman@techsingularity.net: wrong stat is being accumulated in highmem_dirtyable_memory]
  Link: http://lkml.kernel.org/r/20160725092324.GM10438@techsingularity.netLink: http://lkml.kernel.org/r/1469110261-7365-3-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Minchan Kim
71c799f498 mm: add per-zone lru list stat
When I did stress test with hackbench, I got OOM message frequently
which didn't ever happen in zone-lru.

  gfp_mask=0x26004c0(GFP_KERNEL|__GFP_REPEAT|__GFP_NOTRACK), order=0
  ..
  ..
   __alloc_pages_nodemask+0xe52/0xe60
   ? new_slab+0x39c/0x3b0
   new_slab+0x39c/0x3b0
   ___slab_alloc.constprop.87+0x6da/0x840
   ? __alloc_skb+0x3c/0x260
   ? _raw_spin_unlock_irq+0x27/0x60
   ? trace_hardirqs_on_caller+0xec/0x1b0
   ? finish_task_switch+0xa6/0x220
   ? poll_select_copy_remaining+0x140/0x140
   __slab_alloc.isra.81.constprop.86+0x40/0x6d
   ? __alloc_skb+0x3c/0x260
   kmem_cache_alloc+0x22c/0x260
   ? __alloc_skb+0x3c/0x260
   __alloc_skb+0x3c/0x260
   alloc_skb_with_frags+0x4e/0x1a0
   sock_alloc_send_pskb+0x16a/0x1b0
   ? wait_for_unix_gc+0x31/0x90
   ? alloc_set_pte+0x2ad/0x310
   unix_stream_sendmsg+0x28d/0x340
   sock_sendmsg+0x2d/0x40
   sock_write_iter+0x6c/0xc0
   __vfs_write+0xc0/0x120
   vfs_write+0x9b/0x1a0
   ? __might_fault+0x49/0xa0
   SyS_write+0x44/0x90
   do_fast_syscall_32+0xa6/0x1e0
   sysenter_past_esp+0x45/0x74

  Mem-Info:
  active_anon:104698 inactive_anon:105791 isolated_anon:192
   active_file:433 inactive_file:283 isolated_file:22
   unevictable:0 dirty:0 writeback:296 unstable:0
   slab_reclaimable:6389 slab_unreclaimable:78927
   mapped:474 shmem:0 pagetables:101426 bounce:0
   free:10518 free_pcp:334 free_cma:0
  Node 0 active_anon:418792kB inactive_anon:423164kB active_file:1732kB inactive_file:1132kB unevictable:0kB isolated(anon):768kB isolated(file):88kB mapped:1896kB dirty:0kB writeback:1184kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:1478632 all_unreclaimable? yes
  DMA free:3304kB min:68kB low:84kB high:100kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:4088kB kernel_stack:0kB pagetables:2480kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
  lowmem_reserve[]: 0 809 1965 1965
  Normal free:3436kB min:3604kB low:4504kB high:5404kB present:897016kB managed:858460kB mlocked:0kB slab_reclaimable:25556kB slab_unreclaimable:311712kB kernel_stack:164608kB pagetables:30844kB bounce:0kB free_pcp:620kB local_pcp:104kB free_cma:0kB
  lowmem_reserve[]: 0 0 9247 9247
  HighMem free:33808kB min:512kB low:1796kB high:3080kB present:1183736kB managed:1183736kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:372252kB bounce:0kB free_pcp:428kB local_pcp:72kB free_cma:0kB
  lowmem_reserve[]: 0 0 0 0
  DMA: 2*4kB (UM) 2*8kB (UM) 0*16kB 1*32kB (U) 1*64kB (U) 2*128kB (UM) 1*256kB (U) 1*512kB (M) 0*1024kB 1*2048kB (U) 0*4096kB = 3192kB
  Normal: 33*4kB (MH) 79*8kB (ME) 11*16kB (M) 4*32kB (M) 2*64kB (ME) 2*128kB (EH) 7*256kB (EH) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3244kB
  HighMem: 2590*4kB (UM) 1568*8kB (UM) 491*16kB (UM) 60*32kB (UM) 6*64kB (M) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 33064kB
  Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
  25121 total pagecache pages
  24160 pages in swap cache
  Swap cache stats: add 86371, delete 62211, find 42865/60187
  Free swap  = 4015560kB
  Total swap = 4192252kB
  524186 pages RAM
  295934 pages HighMem/MovableOnly
  9658 pages reserved
  0 pages cma reserved

The order-0 allocation for normal zone failed while there are a lot of
reclaimable memory(i.e., anonymous memory with free swap).  I wanted to
analyze the problem but it was hard because we removed per-zone lru stat
so I couldn't know how many of anonymous memory there are in normal/dma
zone.

When we investigate OOM problem, reclaimable memory count is crucial
stat to find a problem.  Without it, it's hard to parse the OOM message
so I believe we should keep it.

With per-zone lru stat,

  gfp_mask=0x26004c0(GFP_KERNEL|__GFP_REPEAT|__GFP_NOTRACK), order=0
  Mem-Info:
  active_anon:101103 inactive_anon:102219 isolated_anon:0
   active_file:503 inactive_file:544 isolated_file:0
   unevictable:0 dirty:0 writeback:34 unstable:0
   slab_reclaimable:6298 slab_unreclaimable:74669
   mapped:863 shmem:0 pagetables:100998 bounce:0
   free:23573 free_pcp:1861 free_cma:0
  Node 0 active_anon:404412kB inactive_anon:409040kB active_file:2012kB inactive_file:2176kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:3452kB dirty:0kB writeback:136kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:1320845 all_unreclaimable? yes
  DMA free:3296kB min:68kB low:84kB high:100kB active_anon:5540kB inactive_anon:0kB active_file:0kB inactive_file:0kB present:15992kB managed:15916kB mlocked:0kB slab_reclaimable:248kB slab_unreclaimable:2628kB kernel_stack:792kB pagetables:2316kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
  lowmem_reserve[]: 0 809 1965 1965
  Normal free:3600kB min:3604kB low:4504kB high:5404kB active_anon:86304kB inactive_anon:0kB active_file:160kB inactive_file:376kB present:897016kB managed:858524kB mlocked:0kB slab_reclaimable:24944kB slab_unreclaimable:296048kB kernel_stack:163832kB pagetables:35892kB bounce:0kB free_pcp:3076kB local_pcp:656kB free_cma:0kB
  lowmem_reserve[]: 0 0 9247 9247
  HighMem free:86156kB min:512kB low:1796kB high:3080kB active_anon:312852kB inactive_anon:410024kB active_file:1924kB inactive_file:2012kB present:1183736kB managed:1183736kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:365784kB bounce:0kB free_pcp:3868kB local_pcp:720kB free_cma:0kB
  lowmem_reserve[]: 0 0 0 0
  DMA: 8*4kB (UM) 8*8kB (UM) 4*16kB (M) 2*32kB (UM) 2*64kB (UM) 1*128kB (M) 3*256kB (UME) 2*512kB (UE) 1*1024kB (E) 0*2048kB 0*4096kB = 3296kB
  Normal: 240*4kB (UME) 160*8kB (UME) 23*16kB (ME) 3*32kB (UE) 3*64kB (UME) 2*128kB (ME) 1*256kB (U) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3408kB
  HighMem: 10942*4kB (UM) 3102*8kB (UM) 866*16kB (UM) 76*32kB (UM) 11*64kB (UM) 4*128kB (UM) 1*256kB (M) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 86344kB
  Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
  54409 total pagecache pages
  53215 pages in swap cache
  Swap cache stats: add 300982, delete 247765, find 157978/226539
  Free swap  = 3803244kB
  Total swap = 4192252kB
  524186 pages RAM
  295934 pages HighMem/MovableOnly
  9642 pages reserved
  0 pages cma reserved

With that, we can see normal zone has a 86M reclaimable memory so we can
know something goes wrong(I will fix the problem in next patch) in
reclaim.

[mgorman@techsingularity.net: rename zone LRU stats in /proc/vmstat]
 Link: http://lkml.kernel.org/r/20160725072300.GK10438@techsingularity.net
Link: http://lkml.kernel.org/r/1469110261-7365-2-git-send-email-mgorman@techsingularity.net
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
785b99febb mm, vmscan: release/reacquire lru_lock on pgdat change
With node-lru, the locking is based on the pgdat.  As Minchan pointed
out, there is an opportunity to reduce LRU lock release/acquire in
check_move_unevictable_pages by only changing lock on a pgdat change.

[mgorman@techsingularity.net: remove double initialisation]
  Link: http://lkml.kernel.org/r/20160719074835.GC10438@techsingularity.net
Link: http://lkml.kernel.org/r/1468853426-12858-3-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
22fecdf5e1 mm, vmscan: remove redundant check in shrink_zones()
As pointed out by Minchan Kim, shrink_zones() checks for populated zones
in a zonelist but a zonelist can never contain unpopulated zones.  While
it's not related to the node-lru series, it can be cleaned up now.

Link: http://lkml.kernel.org/r/1468853426-12858-2-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Suggested-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
7ee36a14f0 mm, vmscan: Update all zone LRU sizes before updating memcg
Minchan Kim reported setting the following warning on a 32-bit system
although it can affect 64-bit systems.

  WARNING: CPU: 4 PID: 1322 at mm/memcontrol.c:998 mem_cgroup_update_lru_size+0x103/0x110
  mem_cgroup_update_lru_size(f44b4000, 1, -7): zid 1 lru_size 1 but empty
  Modules linked in:
  CPU: 4 PID: 1322 Comm: cp Not tainted 4.7.0-rc4-mm1+ #143
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
    dump_stack+0x76/0xaf
    __warn+0xea/0x110
    ? mem_cgroup_update_lru_size+0x103/0x110
    warn_slowpath_fmt+0x3b/0x40
    mem_cgroup_update_lru_size+0x103/0x110
    isolate_lru_pages.isra.61+0x2e2/0x360
    shrink_active_list+0xac/0x2a0
    ? __delay+0xe/0x10
    shrink_node_memcg+0x53c/0x7a0
    shrink_node+0xab/0x2a0
    do_try_to_free_pages+0xc6/0x390
    try_to_free_pages+0x245/0x590

LRU list contents and counts are updated separately.  Counts are updated
before pages are added to the LRU and updated after pages are removed.
The warning above is from a check in mem_cgroup_update_lru_size that
ensures that list sizes of zero are empty.

The problem is that node-lru needs to account for highmem pages if
CONFIG_HIGHMEM is set.  One impact of the implementation is that the
sizes are updated in multiple passes when pages from multiple zones were
isolated.  This happens whether HIGHMEM is set or not.  When multiple
zones are isolated, it's possible for a debugging check in memcg to be
tripped.

This patch forces all the zone counts to be updated before the memcg
function is called.

Link: http://lkml.kernel.org/r/1468588165-12461-6-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Tested-by: Minchan Kim <minchan@kernel.org>
Reported-by: Minchan Kim <minchan@kernel.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Minchan Kim
33e077bd60 mm: show node_pages_scanned per node, not zone
The node_pages_scanned represents the number of scanned pages of node
for reclaim so it's pointless to show it as kilobytes.

As well, node_pages_scanned is per-node value, not per-zone.

This patch changes node_pages_scanned per-zone-killobytes with
per-node-count.

[minchan@kernel.org: fix node_pages_scanned]
  Link: http://lkml.kernel.org/r/20160716101431.GA10305@bbox
Link: http://lkml.kernel.org/r/1468588165-12461-5-git-send-email-mgorman@techsingularity.net
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
68eb0731c4 mm, pagevec: release/reacquire lru_lock on pgdat change
With node-lru, the locking is based on the pgdat.  Previously it was
required that a pagevec drain released one zone lru_lock and acquired
another zone lru_lock on every zone change.  Now, it's only necessary if
the node changes.  The end-result is fewer lock release/acquires if the
pages are all on the same node but in different zones.

Link: http://lkml.kernel.org/r/1468588165-12461-4-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Minchan Kim
9cb937e219 mm, page_alloc: fix dirtyable highmem calculation
When I tested vmscale in mmtest in 32bit, I found the benchmark was slow
down 0.5 times.

                base        node
                   1    global-1
User           12.98       16.04
System        147.61      166.42
Elapsed        26.48       38.08

With vmstat, I found IO wait avg is much increased compared to base.

The reason was highmem_dirtyable_memory accumulates free pages and
highmem_file_pages from HIGHMEM to MOVABLE zones which was wrong.  With
that, dirth_thresh in throtlle_vm_write is always 0 so that it calls
congestion_wait frequently if writeback starts.

With this patch, it is much recovered.

                base        node          fi
                   1    global-1         fix
User           12.98       16.04       13.78
System        147.61      166.42      143.92
Elapsed        26.48       38.08       29.64

Link: http://lkml.kernel.org/r/1468404004-5085-4-git-send-email-mgorman@techsingularity.net
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
bca6759258 mm, vmstat: remove zone and node double accounting by approximating retries
The number of LRU pages, dirty pages and writeback pages must be
accounted for on both zones and nodes because of the reclaim retry
logic, compaction retry logic and highmem calculations all depending on
per-zone stats.

Many lowmem allocations are immune from OOM kill due to a check in
__alloc_pages_may_oom for (ac->high_zoneidx < ZONE_NORMAL) since commit
03668b3ceb ("oom: avoid oom killer for lowmem allocations").  The
exception is costly high-order allocations or allocations that cannot
fail.  If the __alloc_pages_may_oom avoids OOM-kill for low-order lowmem
allocations then it would fall through to __alloc_pages_direct_compact.

This patch will blindly retry reclaim for zone-constrained allocations
in should_reclaim_retry up to MAX_RECLAIM_RETRIES.  This is not ideal
but without per-zone stats there are not many alternatives.  The impact
it that zone-constrained allocations may delay before considering the
OOM killer.

As there is no guarantee enough memory can ever be freed to satisfy
compaction, this patch avoids retrying compaction for zone-contrained
allocations.

In combination, that means that the per-node stats can be used when
deciding whether to continue reclaim using a rough approximation.  While
it is possible this will make the wrong decision on occasion, it will
not infinite loop as the number of reclaim attempts is capped by
MAX_RECLAIM_RETRIES.

The final step is calculating the number of dirtyable highmem pages.  As
those calculations only care about the global count of file pages in
highmem.  This patch uses a global counter used instead of per-zone
stats as it is sufficient.

In combination, this allows the per-zone LRU and dirty state counters to
be removed.

[mgorman@techsingularity.net: fix acct_highmem_file_pages()]
  Link: http://lkml.kernel.org/r/1468853426-12858-4-git-send-email-mgorman@techsingularity.netLink: http://lkml.kernel.org/r/1467970510-21195-35-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Suggested by: Michal Hocko <mhocko@kernel.org>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
e2ecc8a79e mm, vmstat: print node-based stats in zoneinfo file
There are a number of stats that were previously accessible via zoneinfo
that are now invisible.  While it is possible to create a new file for
the node stats, this may be missed by users.  Instead this patch prints
the stats under the first populated zone in /proc/zoneinfo.

Link: http://lkml.kernel.org/r/1467970510-21195-34-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00
Mel Gorman
7cc30fcfd2 mm: vmstat: account per-zone stalls and pages skipped during reclaim
The vmstat allocstall was fairly useful in the general sense but
node-based LRUs change that.  It's important to know if a stall was for
an address-limited allocation request as this will require skipping
pages from other zones.  This patch adds pgstall_* counters to replace
allocstall.  The sum of the counters will equal the old allocstall so it
can be trivially recalculated.  A high number of address-limited
allocation requests may result in a lot of useless LRU scanning for
suitable pages.

As address-limited allocations require pages to be skipped, it's
important to know how much useless LRU scanning took place so this patch
adds pgskip* counters.  This yields the following model

1. The number of address-space limited stalls can be accounted for (pgstall)
2. The amount of useless work required to reclaim the data is accounted (pgskip)
3. The total number of scans is available from pgscan_kswapd and pgscan_direct
   so from that the ratio of useful to useless scans can be calculated.

[mgorman@techsingularity.net: s/pgstall/allocstall/]
  Link: http://lkml.kernel.org/r/1468404004-5085-3-git-send-email-mgorman@techsingularity.netLink: http://lkml.kernel.org/r/1467970510-21195-33-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28 16:07:41 -07:00