The current duplication is a high-maintenance mess, and it's painful to
add new items.

This increases the size of the event array, but we'll eventually want
most of the VM events tracked on a per-cgroup basis anyway.

Link: http://lkml.kernel.org/r/20170404220148.28338-2-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We only ever count single events, drop the @nr parameter.  Rename the
function accordingly.  Remove low-information kerneldoc.

Link: http://lkml.kernel.org/r/20170404220148.28338-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NVladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 59dc76b0 ("mm: vmscan: reduce size of inactive file
list") we noticed bigger IO spikes during changes in cache access
patterns.

The patch in question shrunk the inactive list size to leave more room
for the current workingset in the presence of streaming IO.  However,
workingset transitions that previously happened on the inactive list are
now pushed out of memory and incur more refaults to complete.

This patch disables active list protection when refaults are being
observed.  This accelerates workingset transitions, and allows more of
the new set to establish itself from memory, without eating into the
ability to protect the established workingset during stable periods.

The workloads that were measurably affected for us were hit pretty bad
by it, with refault/majfault rates doubling and tripling during cache
transitions, and the machines sustaining half-hour periods of 100% IO
utilization, where they'd previously have sub-minute peaks at 60-90%.

Stateful services that handle user data tend to be more conservative
with kernel upgrades.  As a result we hit most page cache issues with
some delay, as was the case here.

The severity seemed to warrant a stable tag.

Fixes: 59dc76b0 ("mm: vmscan: reduce size of inactive file list")
Link: http://lkml.kernel.org/r/20170404220052.27593-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>	[4.7+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix variable name error in comments. No code changes.

Link: http://lkml.kernel.org/r/20170403161655.5081-1-haolee.swjtu@gmail.comSigned-off-by: NHao Lee <haolee.swjtu@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It is preferred, and the rest of migrate.h gets it right.

Link: http://lkml.kernel.org/r/1490336009-8024-1-git-send-email-pushkar.iit@gmail.comSigned-off-by: NPushkar Jambhlekar <pushkar.iit@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On SPARSEMEM systems page poisoning is enabled after buddy is up,
because of the dependency on page extension init.  This causes the pages
released by free_all_bootmem not to be poisoned.  This either delays or
misses the identification of some issues because the pages have to
undergo another cycle of alloc-free-alloc for any corruption to be
detected.

Enable page poisoning early by getting rid of the PAGE_EXT_DEBUG_POISON
flag.  Since all the free pages will now be poisoned, the flag need not
be verified before checking the poison during an alloc.

[vinmenon@codeaurora.org: fix Kconfig]
  Link: http://lkml.kernel.org/r/1490878002-14423-1-git-send-email-vinmenon@codeaurora.org
Link: http://lkml.kernel.org/r/1490358246-11001-1-git-send-email-vinmenon@codeaurora.orgSigned-off-by: NVinayak Menon <vinmenon@codeaurora.org>
Acked-by: NLaura Abbott <labbott@redhat.com>
Tested-by: NLaura Abbott <labbott@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no user for it.  Remove it.

[minchan@kernel.org: use false instead of SWAP_FAIL]
  Link: http://lkml.kernel.org/r/20170316053313.GA19241@bbox
Link: http://lkml.kernel.org/r/1489555493-14659-11-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

rmap_one's return value controls whether rmap_work should contine to
scan other ptes or not so it's target for changing to boolean.  Return
true if the scan should be continued.  Otherwise, return false to stop
the scanning.

This patch makes rmap_one's return value to boolean.

Link: http://lkml.kernel.org/r/1489555493-14659-10-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is no user of the return value from rmap_walk() and friends so
this patch makes them void-returning functions.

Link: http://lkml.kernel.org/r/1489555493-14659-9-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

try_to_unmap() returns SWAP_SUCCESS or SWAP_FAIL so it's suitable for
boolean return.  This patch changes it.

Link: http://lkml.kernel.org/r/1489555493-14659-8-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ttu doesn't need to return SWAP_MLOCK.  Instead, just return SWAP_FAIL
because it means the page is not-swappable so it should move to another
LRU list(active or unevictable).  putback friends will move it to right
list depending on the page's LRU flag.

Link: http://lkml.kernel.org/r/1489555493-14659-6-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

try_to_munlock returns SWAP_MLOCK if the one of VMAs mapped the page has
VM_LOCKED flag.  In that time, VM set PG_mlocked to the page if the page
is not pte-mapped THP which cannot be mlocked, either.

With that, __munlock_isolated_page can use PageMlocked to check whether
try_to_munlock is successful or not without relying on try_to_munlock's
retval.  It helps to make try_to_unmap/try_to_unmap_one simple with
upcoming patches.

[minchan@kernel.org: remove PG_Mlocked VM_BUG_ON check]
  Link: http://lkml.kernel.org/r/20170411025615.GA6545@bbox
Link: http://lkml.kernel.org/r/1489555493-14659-5-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If we found lazyfree page is dirty, try_to_unmap_one can just
SetPageSwapBakced in there like PG_mlocked page and just return with
SWAP_FAIL which is very natural because the page is not swappable right
now so that vmscan can activate it.  There is no point to introduce new
return value SWAP_DIRTY in try_to_unmap at the moment.

Link: http://lkml.kernel.org/r/1489555493-14659-3-git-send-email-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 3ad38ceb ("x86/mm: Remove CONFIG_DEBUG_NX_TEST"),
nothing is using the exported rodata_test_data variable, so drop the
export.

This additionally updates the pr_fmt to avoid redundant strings and
adjusts some whitespace.

Link: http://lkml.kernel.org/r/20170307005313.GA85809@beastSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Jinbum Park <jinb.park7@gmail.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

now that we have memalloc_nofs_{save,restore} api we can mark the whole
transaction context as implicitly GFP_NOFS.  All allocations will
automatically inherit GFP_NOFS this way.  This means that we do not have
to mark any of those requests with GFP_NOFS and moreover all the
ext4_kv[mz]alloc(GFP_NOFS) are also safe now because even the hardcoded
GFP_KERNEL allocations deep inside the vmalloc will be NOFS now.

[akpm@linux-foundation.org: tweak comments]
Link: http://lkml.kernel.org/r/20170306131408.9828-7-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

GFP_NOFS context is used for the following 5 reasons currently:

 - to prevent from deadlocks when the lock held by the allocation
   context would be needed during the memory reclaim

 - to prevent from stack overflows during the reclaim because the
   allocation is performed from a deep context already

 - to prevent lockups when the allocation context depends on other
   reclaimers to make a forward progress indirectly

 - just in case because this would be safe from the fs POV

 - silence lockdep false positives

Unfortunately overuse of this allocation context brings some problems to
the MM.  Memory reclaim is much weaker (especially during heavy FS
metadata workloads), OOM killer cannot be invoked because the MM layer
doesn't have enough information about how much memory is freeable by the
FS layer.

In many cases it is far from clear why the weaker context is even used
and so it might be used unnecessarily.  We would like to get rid of
those as much as possible.  One way to do that is to use the flag in
scopes rather than isolated cases.  Such a scope is declared when really
necessary, tracked per task and all the allocation requests from within
the context will simply inherit the GFP_NOFS semantic.

Not only this is easier to understand and maintain because there are
much less problematic contexts than specific allocation requests, this
also helps code paths where FS layer interacts with other layers (e.g.
crypto, security modules, MM etc...) and there is no easy way to convey
the allocation context between the layers.

Introduce memalloc_nofs_{save,restore} API to control the scope of
GFP_NOFS allocation context.  This is basically copying
memalloc_noio_{save,restore} API we have for other restricted allocation
context GFP_NOIO.  The PF_MEMALLOC_NOFS flag already exists and it is
just an alias for PF_FSTRANS which has been xfs specific until recently.
There are no more PF_FSTRANS users anymore so let's just drop it.

PF_MEMALLOC_NOFS is now checked in the MM layer and drops __GFP_FS
implicitly same as PF_MEMALLOC_NOIO drops __GFP_IO.  memalloc_noio_flags
is renamed to current_gfp_context because it now cares about both
PF_MEMALLOC_NOFS and PF_MEMALLOC_NOIO contexts.  Xfs code paths preserve
their semantic.  kmem_flags_convert() doesn't need to evaluate the flag
anymore.

This patch shouldn't introduce any functional changes.

Let's hope that filesystems will drop direct GFP_NOFS (resp.  ~__GFP_FS)
usage as much as possible and only use a properly documented
memalloc_nofs_{save,restore} checkpoints where they are appropriate.

[akpm@linux-foundation.org: fix comment typo, reflow comment]
Link: http://lkml.kernel.org/r/20170306131408.9828-5-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

xfs has defined PF_FSTRANS to declare a scope GFP_NOFS semantic quite
some time ago.  We would like to make this concept more generic and use
it for other filesystems as well.  Let's start by giving the flag a more
generic name PF_MEMALLOC_NOFS which is in line with an exiting
PF_MEMALLOC_NOIO already used for the same purpose for GFP_NOIO
contexts.  Replace all PF_FSTRANS usage from the xfs code in the first
step before we introduce a full API for it as xfs uses the flag directly
anyway.

This patch doesn't introduce any functional change.

Link: http://lkml.kernel.org/r/20170306131408.9828-4-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current implementation of the reclaim lockup detection can lead to
false positives and those even happen and usually lead to tweak the code
to silence the lockdep by using GFP_NOFS even though the context can use
__GFP_FS just fine.

See

  http://lkml.kernel.org/r/20160512080321.GA18496@dastard

as an example.

  =================================
  [ INFO: inconsistent lock state ]
  4.5.0-rc2+ #4 Tainted: G           O
  ---------------------------------
  inconsistent {RECLAIM_FS-ON-R} -> {IN-RECLAIM_FS-W} usage.
  kswapd0/543 [HC0[0]:SC0[0]:HE1:SE1] takes:

  (&xfs_nondir_ilock_class){++++-+}, at: xfs_ilock+0x177/0x200 [xfs]

  {RECLAIM_FS-ON-R} state was registered at:
    mark_held_locks+0x79/0xa0
    lockdep_trace_alloc+0xb3/0x100
    kmem_cache_alloc+0x33/0x230
    kmem_zone_alloc+0x81/0x120 [xfs]
    xfs_refcountbt_init_cursor+0x3e/0xa0 [xfs]
    __xfs_refcount_find_shared+0x75/0x580 [xfs]
    xfs_refcount_find_shared+0x84/0xb0 [xfs]
    xfs_getbmap+0x608/0x8c0 [xfs]
    xfs_vn_fiemap+0xab/0xc0 [xfs]
    do_vfs_ioctl+0x498/0x670
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x12/0x6f

         CPU0
         ----
    lock(&xfs_nondir_ilock_class);
    <Interrupt>
      lock(&xfs_nondir_ilock_class);

   *** DEADLOCK ***

  3 locks held by kswapd0/543:

  stack backtrace:
  CPU: 0 PID: 543 Comm: kswapd0 Tainted: G           O    4.5.0-rc2+ #4
  Call Trace:
   lock_acquire+0xd8/0x1e0
   down_write_nested+0x5e/0xc0
   xfs_ilock+0x177/0x200 [xfs]
   xfs_reflink_cancel_cow_range+0x150/0x300 [xfs]
   xfs_fs_evict_inode+0xdc/0x1e0 [xfs]
   evict+0xc5/0x190
   dispose_list+0x39/0x60
   prune_icache_sb+0x4b/0x60
   super_cache_scan+0x14f/0x1a0
   shrink_slab.part.63.constprop.79+0x1e9/0x4e0
   shrink_zone+0x15e/0x170
   kswapd+0x4f1/0xa80
   kthread+0xf2/0x110
   ret_from_fork+0x3f/0x70

To quote Dave:
 "Ignoring whether reflink should be doing anything or not, that's a
  "xfs_refcountbt_init_cursor() gets called both outside and inside
  transactions" lockdep false positive case. The problem here is lockdep
  has seen this allocation from within a transaction, hence a GFP_NOFS
  allocation, and now it's seeing it in a GFP_KERNEL context. Also note
  that we have an active reference to this inode.

  So, because the reclaim annotations overload the interrupt level
  detections and it's seen the inode ilock been taken in reclaim
  ("interrupt") context, this triggers a reclaim context warning where
  it thinks it is unsafe to do this allocation in GFP_KERNEL context
  holding the inode ilock..."

This sounds like a fundamental problem of the reclaim lock detection.
It is really impossible to annotate such a special usecase IMHO unless
the reclaim lockup detection is reworked completely.  Until then it is
much better to provide a way to add "I know what I am doing flag" and
mark problematic places.  This would prevent from abusing GFP_NOFS flag
which has a runtime effect even on configurations which have lockdep
disabled.

Introduce __GFP_NOLOCKDEP flag which tells the lockdep gfp tracking to
skip the current allocation request.

While we are at it also make sure that the radix tree doesn't
accidentaly override tags stored in the upper part of the gfp_mask.

Link: http://lkml.kernel.org/r/20170306131408.9828-3-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduce two helpers, is_migrate_highatomic() and is_migrate_highatomic_page().

Simplify the code, no functional changes.

[akpm@linux-foundation.org: use static inlines rather than macros, per mhocko]
Link: http://lkml.kernel.org/r/58B94F15.6060606@huawei.comSigned-off-by: NXishi Qiu <qiuxishi@huawei.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cgroups currently don't report how much shmem they use, which can be
useful data to have, in particular since shmem is included in the
cache/file item while being reclaimed like anonymous memory.

Add a counter to track shmem pages during charging and uncharging.

Link: http://lkml.kernel.org/r/20170221164343.32252-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NChris Down <cdown@fb.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When memory pressure is high, we free MADV_FREE pages.  If the pages are
not dirty in pte, the pages could be freed immediately.  Otherwise we
can't reclaim them.  We put the pages back to anonumous LRU list (by
setting SwapBacked flag) and the pages will be reclaimed in normal
swapout way.

We use normal page reclaim policy.  Since MADV_FREE pages are put into
inactive file list, such pages and inactive file pages are reclaimed
according to their age.  This is expected, because we don't want to
reclaim too many MADV_FREE pages before used once pages.

Based on Minchan's original patch

[minchan@kernel.org: clean up lazyfree page handling]
  Link: http://lkml.kernel.org/r/20170303025237.GB3503@bbox
Link: http://lkml.kernel.org/r/14b8eb1d3f6bf6cc492833f183ac8c304e560484.1487965799.git.shli@fb.comSigned-off-by: NShaohua Li <shli@fb.com>
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

madv()'s MADV_FREE indicate pages are 'lazyfree'.  They are still
anonymous pages, but they can be freed without pageout.  To distinguish
these from normal anonymous pages, we clear their SwapBacked flag.

MADV_FREE pages could be freed without pageout, so they pretty much like
used once file pages.  For such pages, we'd like to reclaim them once
there is memory pressure.  Also it might be unfair reclaiming MADV_FREE
pages always before used once file pages and we definitively want to
reclaim the pages before other anonymous and file pages.

To speed up MADV_FREE pages reclaim, we put the pages into
LRU_INACTIVE_FILE list.  The rationale is LRU_INACTIVE_FILE list is tiny
nowadays and should be full of used once file pages.  Reclaiming
MADV_FREE pages will not have much interfere of anonymous and active
file pages.  And the inactive file pages and MADV_FREE pages will be
reclaimed according to their age, so we don't reclaim too many MADV_FREE
pages too.  Putting the MADV_FREE pages into LRU_INACTIVE_FILE_LIST also
means we can reclaim the pages without swap support.  This idea is
suggested by Johannes.

This patch doesn't move MADV_FREE pages to LRU_INACTIVE_FILE list yet to
avoid bisect failure, next patch will do it.

The patch is based on Minchan's original patch.

[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/2f87063c1e9354677b7618c647abde77b07561e5.1487965799.git.shli@fb.comSigned-off-by: NShaohua Li <shli@fb.com>
Suggested-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: fix some MADV_FREE issues", v5.

We are trying to use MADV_FREE in jemalloc.  Several issues are found.
Without solving the issues, jemalloc can't use the MADV_FREE feature.

 - Doesn't support system without swap enabled. Because if swap is off,
   we can't or can't efficiently age anonymous pages. And since
   MADV_FREE pages are mixed with other anonymous pages, we can't
   reclaim MADV_FREE pages. In current implementation, MADV_FREE will
   fallback to MADV_DONTNEED without swap enabled. But in our
   environment, a lot of machines don't enable swap. This will prevent
   our setup using MADV_FREE.

 - Increases memory pressure. page reclaim bias file pages reclaim
   against anonymous pages. This doesn't make sense for MADV_FREE pages,
   because those pages could be freed easily and refilled with very
   slight penality. Even page reclaim doesn't bias file pages, there is
   still an issue, because MADV_FREE pages and other anonymous pages are
   mixed together. To reclaim a MADV_FREE page, we probably must scan a
   lot of other anonymous pages, which is inefficient. In our test, we
   usually see oom with MADV_FREE enabled and nothing without it.

 - Accounting. There are two accounting problems. We don't have a global
   accounting. If the system is abnormal, we don't know if it's a
   problem from MADV_FREE side. The other problem is RSS accounting.
   MADV_FREE pages are accounted as normal anon pages and reclaimed
   lazily, so application's RSS becomes bigger. This confuses our
   workloads. We have monitoring daemon running and if it finds
   applications' RSS becomes abnormal, the daemon will kill the
   applications even kernel can reclaim the memory easily.

To address the first the two issues, we can either put MADV_FREE pages
into a separate LRU list (Minchan's previous patches and V1 patches), or
put them into LRU_INACTIVE_FILE list (suggested by Johannes).  The
patchset use the second idea.  The reason is LRU_INACTIVE_FILE list is
tiny nowadays and should be full of used once file pages.  So we can
still efficiently reclaim MADV_FREE pages there without interference
with other anon and active file pages.  Putting the pages into inactive
file list also has an advantage which allows page reclaim to prioritize
MADV_FREE pages and used once file pages.  MADV_FREE pages are put into
the lru list and clear SwapBacked flag, so PageAnon(page) &&
!PageSwapBacked(page) will indicate a MADV_FREE pages.  These pages will
directly freed without pageout if they are clean, otherwise normal swap
will reclaim them.

For the third issue, the previous post adds global accounting and a
separate RSS count for MADV_FREE pages.  The problem is we never get
accurate accounting for MADV_FREE pages.  The pages are mapped to
userspace, can be dirtied without notice from kernel side.  To get
accurate accounting, we could write protect the page, but then there is
extra page fault overhead, which people don't want to pay.  Jemalloc
guys have concerns about the inaccurate accounting, so this post drops
the accounting patches temporarily.  The info exported to
/proc/pid/smaps for MADV_FREE pages are kept, which is the only place we
can get accurate accounting right now.

This patch (of 6):

Johannes pointed out TTU_LZFREE is unnecessary.  It's true because we
always have the flag set if we want to do an unmap.  For cases we don't
do an unmap, the TTU_LZFREE part of code should never run.

Also the TTU_UNMAP is unnecessary.  If no other flags set (for example,
TTU_MIGRATION), an unmap is implied.

The patch includes Johannes's cleanup and dead TTU_ACTION macro removal
code

Link: http://lkml.kernel.org/r/4be3ea1bc56b26fd98a54d0a6f70bec63f6d8980.1487965799.git.shli@fb.comSigned-off-by: NShaohua Li <shli@fb.com>
Suggested-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

NR_PAGES_SCANNED counts number of pages scanned since the last page free
event in the allocator.  This was used primarily to measure the
reclaimability of zones and nodes, and determine when reclaim should
give up on them.  In that role, it has been replaced in the preceding
patches by a different mechanism.

Being implemented as an efficient vmstat counter, it was automatically
exported to userspace as well.  It's however unlikely that anyone
outside the kernel is using this counter in any meaningful way.

Remove the counter and the unused pgdat_reclaimable().

Link: http://lkml.kernel.org/r/20170228214007.5621-8-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Jia He <hejianet@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: kswapd spinning on unreclaimable nodes - fixes and
cleanups".

Jia reported a scenario in which the kswapd of a node indefinitely spins
at 100% CPU usage.  We have seen similar cases at Facebook.

The kernel's current method of judging its ability to reclaim a node (or
whether to back off and sleep) is based on the amount of scanned pages
in proportion to the amount of reclaimable pages.  In Jia's and our
scenarios, there are no reclaimable pages in the node, however, and the
condition for backing off is never met.  Kswapd busyloops in an attempt
to restore the watermarks while having nothing to work with.

This series reworks the definition of an unreclaimable node based not on
scanning but on whether kswapd is able to actually reclaim pages in
MAX_RECLAIM_RETRIES (16) consecutive runs.  This is the same criteria
the page allocator uses for giving up on direct reclaim and invoking the
OOM killer.  If it cannot free any pages, kswapd will go to sleep and
leave further attempts to direct reclaim invocations, which will either
make progress and re-enable kswapd, or invoke the OOM killer.

Patch #1 fixes the immediate problem Jia reported, the remainder are
smaller fixlets, cleanups, and overall phasing out of the old method.

Patch #6 is the odd one out.  It's a nice cleanup to get_scan_count(),
and directly related to #5, but in itself not relevant to the series.

If the whole series is too ambitious for 4.11, I would consider the
first three patches fixes, the rest cleanups.

This patch (of 9):

Jia He reports a problem with kswapd spinning at 100% CPU when
requesting more hugepages than memory available in the system:

$ echo 4000 >/proc/sys/vm/nr_hugepages

top - 13:42:59 up  3:37,  1 user,  load average: 1.09, 1.03, 1.01
Tasks:   1 total,   1 running,   0 sleeping,   0 stopped,   0 zombie
%Cpu(s):  0.0 us, 12.5 sy,  0.0 ni, 85.5 id,  2.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem:  31371520 total, 30915136 used,   456384 free,      320 buffers
KiB Swap:  6284224 total,   115712 used,  6168512 free.    48192 cached Mem

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
   76 root      20   0       0      0      0 R 100.0 0.000 217:17.29 kswapd3

At that time, there are no reclaimable pages left in the node, but as
kswapd fails to restore the high watermarks it refuses to go to sleep.

Kswapd needs to back away from nodes that fail to balance.  Up until
commit 1d82de61 ("mm, vmscan: make kswapd reclaim in terms of
nodes") kswapd had such a mechanism.  It considered zones whose
theoretically reclaimable pages it had reclaimed six times over as
unreclaimable and backed away from them.  This guard was erroneously
removed as the patch changed the definition of a balanced node.

However, simply restoring this code wouldn't help in the case reported
here: there *are* no reclaimable pages that could be scanned until the
threshold is met.  Kswapd would stay awake anyway.

Introduce a new and much simpler way of backing off.  If kswapd runs
through MAX_RECLAIM_RETRIES (16) cycles without reclaiming a single
page, make it back off from the node.  This is the same number of shots
direct reclaim takes before declaring OOM.  Kswapd will go to sleep on
that node until a direct reclaimer manages to reclaim some pages, thus
proving the node reclaimable again.

[hannes@cmpxchg.org: check kswapd failure against the cumulative nr_reclaimed count]
  Link: http://lkml.kernel.org/r/20170306162410.GB2090@cmpxchg.org
[shakeelb@google.com: fix condition for throttle_direct_reclaim]
  Link: http://lkml.kernel.org/r/20170314183228.20152-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20170228214007.5621-2-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NShakeel Butt <shakeelb@google.com>
Reported-by: NJia He <hejianet@gmail.com>
Tested-by: NJia He <hejianet@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NHillf Danton <hillf.zj@alibaba-inc.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Jump is now the only one using value action opcode. This is going to
change soon. So introduce helpers to work with this. Convert TC_ACT_JUMP.

This also fixes the TC_ACT_JUMP check, which is incorrectly done as a
bit check, not a value check.

Fixes: e0ee84de ("net sched actions: Complete the JUMPX opcode")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

PTP hardware filter configuration performed by the driver for a given
user requested config is not correct for some of the PTP modes.
Following changes are needed for PTP config-filter implementation.
 1. NIG_REG_TX_PTP_EN register - Bits 0/1/2 respectively enables
    TimeSync/"V1 frame format support"/"V2 frame format support" on
    the TX side. Set the associated bits based on the user request.
 2. ptp4l application fails to operate in Peer Delay mode. Following
    changes are needed to fix this,
    a. Driver should enable (set to 0) DA #1-related bits for IPv4,
       IPv6 and MAC destination addresses in these registers:
         NIG_REG_TX_LLH_PTP_RULE_MASK
         NIG_REG_LLH_PTP_RULE_MASK
    b. NIG_REG_LLH_PTP_PARAM_MASK/NIG_REG_TX_LLH_PTP_PARAM_MASK should
       be set to 0x0 in all modes.
Signed-off-by: NSudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct timespec is not y2038 safe.
Audit timestamps are recorded in string format into
an audit buffer for a given context.
These mark the entry timestamps for the syscalls.
Use y2038 safe struct timespec64 to represent the times.
The log strings can handle this transition as strings can
hold upto 1024 characters.
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NPaul Moore <paul@paul-moore.com>
Acked-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NPaul Moore <paul@paul-moore.com>

We were setting the portid incorrectly in the netlink message headers,
fix that to always be 0 (nlmsg_pid = 0).
Signed-off-by: NPaul Moore <paul@paul-moore.com>
Reviewed-by: NRichard Guy Briggs <rgb@redhat.com>

By using smaller datatypes this (rather large) struct shrinks considerably
(80 -> 48 bytes on x86_64).

As this is embedded in other structs, this also rerduces size of several
others, e.g. cls_fl_head or nft_hash.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Output to the RDMA driver whether DPM mode is enabled or disabled in
the HW and if so what is the number of WIDs it supports
Signed-off-by: NRam Amrani <Ram.Amrani@cavium.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Drivers usually have a number of restrictions for running XDP
- most common being buffer sizes, LRO and number of rings.
Even though some drivers try to be helpful and print error
messages experience shows that users don't often consult
kernel logs on netlink errors.  Try to use the new extended
ack mechanism to carry the message back to user space.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As we propagate extended ack reporting throughout various paths in
the kernel it may be that the same function is called with the
extended ack parameter passed as NULL.  One place where that happens
is in drivers which have a centralized reconfiguration function
called both from ndos and from ethtool_ops.  Add a new helper for
setting the error message in such conditions.

Existing helper is left as is to encourage propagating the ext act
fully wherever possible.  It also makes it clear in the code which
messages may be lost due to ext ack being NULL.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For NF_NAT_MANIP_SRC, we will insert the ct to the nat_bysource_table,
then remove it from the nat_bysource_table via nat_extend->destroy.

But now, the nat extension is attached on demand, so if the nat extension
is not attached, we will not be notified when the ct is destroyed, i.e.
we may fail to remove ct from the nat_bysource_table.

So just keep it simple, even if the extension is not attached, we will
still invoke the related ext->destroy. And this will also preserve the
flexibility for the future extension.

Fixes: 9a08ecfe ("netfilter: don't attach a nat extension by default")
Signed-off-by: NLiping Zhang <zlpnobody@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

nf_unregister_net_hook(s) can avoid a second call to synchronize_net,
provided there is no nfqueue active in that net namespace (which is
the common case).

This also gets rid of the extra arg to nf_queue_nf_hook_drop(), normally
this gets called during netns cleanup so no packets should be queued.

For the rare case of base chain being unregistered or module removal
while nfqueue is in use the extra hiccup due to the packet drops isn't
a big deal.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch drops support for AVR32 architecture from the Linux kernel.

The AVR32 architecture is not keeping up with the development of the
kernel, and since it shares so much of the drivers with Atmel ARM SoC,
it is starting to hinder these drivers to develop swiftly.

Also, all AVR32 AP7 SoC processors are end of lifed from Atmel (now
Microchip).

Finally, the GCC toolchain is stuck at version 4.2.x, and has not
received any patches since the last release from Atmel;
4.2.4-atmel.1.1.3.avr32linux.1. When building kernel v4.10, this
toolchain is no longer able to properly link the network stack.

Haavard and I have came to the conclusion that we feel keeping AVR32 on
life support offers more obstacles for Atmel ARMs, than it gives joy to
AVR32 users. I also suspect there are very few AVR32 users left today,
if anybody at all.
Signed-off-by: NHans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Signed-off-by: NHåvard Skinnemoen <hskinnemoen@gmail.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

The x86 conversion to the generic GUP code included a small change which causes
crashes and data corruption in the pmem code - not good.

The root cause is that the /dev/pmem driver code implicitly relies on the x86
get_user_pages() implementation doing a get_page() on the page refcount, because
get_page() does a get_zone_device_page() which properly refcounts pmem's separate
page struct arrays that are not present in the regular page struct structures.
(The pmem driver does this because it can cover huge memory areas.)

But the x86 conversion to the generic GUP code changed the get_page() to
page_cache_get_speculative() which is faster but doesn't do the
get_zone_device_page() call the pmem code relies on.

One way to solve the regression would be to change the generic GUP code to use
get_page(), but that would slow things down a bit and punish other generic-GUP
using architectures for an x86-ism they did not care about. (Arguably the pmem
driver was probably not working reliably for them: but nvdimm is an Intel
feature, so non-x86 exposure is probably still limited.)

So restructure the pmem code's interface with the MM instead: get rid of the
get/put_zone_device_page() distinction, integrate put_zone_device_page() into
__put_page() and and restructure the pmem completion-wait and teardown machinery:

Kirill points out that the calls to {get,put}_dev_pagemap() can be
removed from the mm fast path if we take a single get_dev_pagemap()
reference to signify that the page is alive and use the final put of the
page to drop that reference.

This does require some care to make sure that any waits for the
percpu_ref to drop to zero occur *after* devm_memremap_page_release(),
since it now maintains its own elevated reference.

This speeds up things while also making the pmem refcounting more robust going
forward.
Suggested-by: NKirill Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: NKirill Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NLogan Gunthorpe <logang@deltatee.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/149339998297.24933.1129582806028305912.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The description inside uapi/linux/bpf.h about bpf_get_socket_uid
helper function is no longer valid. It returns overflowuid rather
than 0 when failed.
Signed-off-by: NChenbo Feng <fengc@google.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When IP tunnel encapsulation rules are offloaded, the kernel can't see
the traffic of the offloaded flow. The neighbour for the IP tunnel
destination of the offloaded flow can mistakenly become STALE and
deleted by the kernel since its 'used' value wasn't changed.

To make sure that a neighbour which is used by the HW won't become
STALE, we proactively update the neighbour 'used' value every
DELAY_PROBE_TIME period, when packets were matched and counted by the HW
for one of the tunnel encap flows related to this neighbour.

The periodic task that updates the used neighbours is scheduled when a
tunnel encap rule is successfully offloaded into HW and keeps re-scheduling
itself as long as the representor's neighbours list isn't empty.

Add, remove, lookup and status change operations done over the
representor's neighbours list or the neighbour hash entry encaps list
are all serialized by RTNL lock.
Signed-off-by: NHadar Hen Zion <hadarh@mellanox.com>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

This was already disabled a while ago because it caused I/O errors,
and it's severly getting into the way of the discard / write zeroes
rework.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NTejun Heo <tj@kernel.org>