linux.git/mm/memory-failure.c, branch v3.19

mm: vmscan: invoke slab shrinkers from shrink_zone()

2014-12-13T20:42:48+00:00

The slab shrinkers are currently invoked from the zonelist walkers in
kswapd, direct reclaim, and zone reclaim, all of which roughly gauge the
eligible LRU pages and assemble a nodemask to pass to NUMA-aware
shrinkers, which then again have to walk over the nodemask.  This is
redundant code, extra runtime work, and fairly inaccurate when it comes to
the estimation of actually scannable LRU pages.  The code duplication will
only get worse when making the shrinkers cgroup-aware and requiring them
to have out-of-band cgroup hierarchy walks as well.

Instead, invoke the shrinkers from shrink_zone(), which is where all
reclaimers end up, to avoid this duplication.

Take the count for eligible LRU pages out of get_scan_count(), which
considers many more factors than just the availability of swap space, like
zone_reclaimable_pages() currently does.  Accumulate the number over all
visited lruvecs to get the per-zone value.

Some nodes have multiple zones due to memory addressing restrictions.  To
avoid putting too much pressure on the shrinkers, only invoke them once
for each such node, using the class zone of the allocation as the pivot
zone.

For now, this integrates the slab shrinking better into the reclaim logic
and gets rid of duplicative invocations from kswapd, direct reclaim, and
zone reclaim.  It also prepares for cgroup-awareness, allowing
memcg-capable shrinkers to be added at the lruvec level without much
duplication of both code and runtime work.

This changes kswapd behavior, which used to invoke the shrinkers for each
zone, but with scan ratios gathered from the entire node, resulting in
meaningless pressure quantities on multi-zone nodes.

Zone reclaim behavior also changes.  It used to shrink slabs until the
same amount of pages were shrunk as were reclaimed from the LRUs.  Now it
merely invokes the shrinkers once with the zone's scan ratio, which makes
the shrinkers go easier on caches that implement aging and would prefer
feeding back pressure from recently used slab objects to unused LRU pages.

[vdavydov@parallels.com: assure class zone is populated]
Signed-off-by: Johannes Weiner 
Cc: Dave Chinner 
Signed-off-by: Vladimir Davydov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory-failure: share the i_mmap_rwsem

2014-12-13T20:42:45+00:00

No brainer conversion: collect_procs_file() only schedules a process for
later kill, share the lock, similarly to the anon vma variant.

Signed-off-by: Davidlohr Bueso 
Acked-by: "Kirill A. Shutemov" 
Acked-by: Hugh Dickins 
Cc: Oleg Nesterov 
Acked-by: Peter Zijlstra (Intel) 
Cc: Rik van Riel 
Cc: Srikar Dronamraju 
Acked-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: use new helper functions around the i_mmap_mutex

2014-12-13T20:42:45+00:00

Convert all open coded mutex_lock/unlock calls to the
i_mmap_[lock/unlock]_write() helpers.

Signed-off-by: Davidlohr Bueso 
Acked-by: Rik van Riel 
Acked-by: "Kirill A. Shutemov" 
Acked-by: Hugh Dickins 
Cc: Oleg Nesterov 
Acked-by: Peter Zijlstra (Intel) 
Cc: Srikar Dronamraju 
Acked-by: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patchbomb from Andrew)

2014-12-11T02:34:42+00:00

Merge first patchbomb from Andrew Morton:
 - a few minor cifs fixes
 - dma-debug upadtes
 - ocfs2
 - slab
 - about half of MM
 - procfs
 - kernel/exit.c
 - panic.c tweaks
 - printk upates
 - lib/ updates
 - checkpatch updates
 - fs/binfmt updates
 - the drivers/rtc tree
 - nilfs
 - kmod fixes
 - more kernel/exit.c
 - various other misc tweaks and fixes

* emailed patches from Andrew Morton : (190 commits)
  exit: pidns: fix/update the comments in zap_pid_ns_processes()
  exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting
  exit: exit_notify: re-use "dead" list to autoreap current
  exit: reparent: call forget_original_parent() under tasklist_lock
  exit: reparent: avoid find_new_reaper() if no children
  exit: reparent: introduce find_alive_thread()
  exit: reparent: introduce find_child_reaper()
  exit: reparent: document the ->has_child_subreaper checks
  exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper()
  exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting
  exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting
  exit: proc: don't try to flush /proc/tgid/task/tgid
  exit: release_task: fix the comment about group leader accounting
  exit: wait: drop tasklist_lock before psig->c* accounting
  exit: wait: don't use zombie->real_parent
  exit: wait: cleanup the ptrace_reparented() checks
  usermodehelper: kill the kmod_thread_locker logic
  usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper()
  fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp
  nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races
  ...

mm, memory_hotplug/failure: drain single zone pcplists

2014-12-11T01:41:05+00:00

Memory hotplug and failure mechanisms have several places where pcplists
are drained so that pages are returned to the buddy allocator and can be
e.g. prepared for offlining.  This is always done in the context of a
single zone, we can reduce the pcplists drain to the single zone, which
is now possible.

The change should make memory offlining due to hotremove or failure
faster and not disturbing unrelated pcplists anymore.

Signed-off-by: Vlastimil Babka 
Cc: Naoya Horiguchi 
Cc: Mel Gorman 
Cc: Rik van Riel 
Cc: Yasuaki Ishimatsu 
Cc: Zhang Yanfei 
Cc: Xishi Qiu 
Cc: Vladimir Davydov 
Cc: Joonsoo Kim 
Cc: Michal Nazarewicz 
Cc: Marek Szyprowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: introduce single zone pcplists drain

2014-12-11T01:41:05+00:00

The functions for draining per-cpu pages back to buddy allocators
currently always operate on all zones.  There are however several cases
where the drain is only needed in the context of a single zone, and
spilling other pcplists is a waste of time both due to the extra
spilling and later refilling.

This patch introduces new zone pointer parameter to drain_all_pages()
and changes the dummy parameter of drain_local_pages() to be also a zone
pointer.  When NULL is passed, the functions operate on all zones as
usual.  Passing a specific zone pointer reduces the work to the single
zone.

All callers are updated to pass the NULL pointer in this patch.
Conversion to single zone (where appropriate) is done in further
patches.

Signed-off-by: Vlastimil Babka 
Cc: Naoya Horiguchi 
Cc: Mel Gorman 
Cc: Rik van Riel 
Cc: Yasuaki Ishimatsu 
Cc: Zhang Yanfei 
Cc: Xishi Qiu 
Cc: Vladimir Davydov 
Cc: Joonsoo Kim 
Cc: Michal Nazarewicz 
Cc: Marek Szyprowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

RAS, HWPOISON: Fix wrong error recovery status

2014-10-21T20:06:50+00:00

When Uncorrected error happens, if the poisoned page is referenced
by more than one user after error recovery, the recovery is not
successful. But currently the display result is wrong.
Before this patch:

MCE 0x44e336: dirty mlocked LRU page recovery: Recovered
MCE 0x44e336: dirty mlocked LRU page still referenced by 1 users
mce: Memory error not recovered

After this patch:

MCE 0x44e336: dirty mlocked LRU page recovery: Failed
MCE 0x44e336: dirty mlocked LRU page still referenced by 1 users
mce: Memory error not recovered

Signed-off-by: Chen, Gong 
Link: http://lkml.kernel.org/r/1406530260-26078-3-git-send-email-gong.chen@linux.intel.com
Acked-by: Naoya Horiguchi 
Acked-by: Tony Luck 
Signed-off-by: Borislav Petkov

cgroup: remove redundant check in cgroup_ino()

2014-09-19T13:16:23+00:00

After we implemented default unified hierarchy, cgrp->kn can never
be NULL.

Signed-off-by: Zefan Li 
Signed-off-by: Tejun Heo

hwpoison: fix race with changing page during offlining

2014-08-07T01:01:19+00:00

When a hwpoison page is locked it could change state due to parallel
modifications.  The original compound page can be torn down and then
this 4k page becomes part of a differently-size compound page is is a
standalone regular page.

Check after the lock if the page is still the same compound page.

We could go back, grab the new head page and try again but it should be
quite rare, so I thought this was safest.  A retry loop would be more
difficult to test and may have more side effects.

The hwpoison code by design only tries to handle cases that are
reasonably common in workloads, as visible in page-flags.

I'm not really that concerned about handling this (likely rare case),
just not crashing on it.

Signed-off-by: Andi Kleen 
Acked-by: Naoya Horiguchi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hwpoison: call action_result() in failure path of hwpoison_user_mappings()

2014-07-31T00:16:13+00:00

hwpoison_user_mappings() could fail for various reasons, so printk()s to
print out the reasons should be done in each failure check inside
hwpoison_user_mappings().

And currently we don't call action_result() when hwpoison_user_mappings()
fails, which is not consistent with other exit points of memory error
handler.  So this patch fixes these messaging problems.

Signed-off-by: Naoya Horiguchi 
Cc: Andi Kleen 
Cc: Chen Yucong 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds