linux.git/mm/vmscan.c, branch v3.13

mm/vmscan.c: don't forget to free shrinker->nr_deferred

2013-10-17T04:35:52+00:00

This leak was added by commit 1d3d4437eae1 ("vmscan: per-node deferred
work").

unreferenced object 0xffff88006ada3bd0 (size 8):
  comm "criu", pid 14781, jiffies 4295238251 (age 105.641s)
  hex dump (first 8 bytes):
    00 00 00 00 00 00 00 00                          ........
  backtrace:
    [] kmemleak_alloc+0x5e/0xc0
    [] __kmalloc+0x247/0x310
    [] register_shrinker+0x3c/0xa0
    [] sget+0x5ab/0x670
    [] proc_mount+0x54/0x170
    [] mount_fs+0x43/0x1b0
    [] vfs_kern_mount+0x72/0x110
    [] kern_mount_data+0x19/0x30
    [] pid_ns_prepare_proc+0x20/0x40
    [] alloc_pid+0x466/0x4a0
    [] copy_process+0xc6a/0x1860
    [] do_fork+0x8b/0x370
    [] SyS_clone+0x16/0x20
    [] stub_clone+0x69/0x90
    [] 0xffffffffffffffff

Signed-off-by: Andrew Vagin 
Cc: Mel Gorman 
Cc: Michal Hocko 
Cc: Rik van Riel 
Cc: Johannes Weiner 
Cc: Glauber Costa 
Cc: Chuck Lever 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: avoid reinserting isolated balloon pages into LRU lists

2013-09-30T21:31:02+00:00

Isolated balloon pages can wrongly end up in LRU lists when
migrate_pages() finishes its round without draining all the isolated
page list.

The same issue can happen when reclaim_clean_pages_from_list() tries to
reclaim pages from an isolated page list, before migration, in the CMA
path.  Such balloon page leak opens a race window against LRU lists
shrinkers that leads us to the following kernel panic:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
  IP: [] shrink_page_list+0x24e/0x897
  PGD 3cda2067 PUD 3d713067 PMD 0
  Oops: 0000 [#1] SMP
  CPU: 0 PID: 340 Comm: kswapd0 Not tainted 3.12.0-rc1-22626-g4367597 #87
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  RIP: shrink_page_list+0x24e/0x897
  RSP: 0000:ffff88003da499b8  EFLAGS: 00010286
  RAX: 0000000000000000 RBX: ffff88003e82bd60 RCX: 00000000000657d5
  RDX: 0000000000000000 RSI: 000000000000031f RDI: ffff88003e82bd40
  RBP: ffff88003da49ab0 R08: 0000000000000001 R09: 0000000081121a45
  R10: ffffffff81121a45 R11: ffff88003c4a9a28 R12: ffff88003e82bd40
  R13: ffff88003da0e800 R14: 0000000000000001 R15: ffff88003da49d58
  FS:  0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000067d9000 CR3: 000000003ace5000 CR4: 00000000000407b0
  Call Trace:
    shrink_inactive_list+0x240/0x3de
    shrink_lruvec+0x3e0/0x566
    __shrink_zone+0x94/0x178
    shrink_zone+0x3a/0x82
    balance_pgdat+0x32a/0x4c2
    kswapd+0x2f0/0x372
    kthread+0xa2/0xaa
    ret_from_fork+0x7c/0xb0
  Code: 80 7d 8f 01 48 83 95 68 ff ff ff 00 4c 89 e7 e8 5a 7b 00 00 48 85 c0 49 89 c5 75 08 80 7d 8f 00 74 3e eb 31 48 8b 80 18 01 00 00 <48> 8b 74 0d 48 8b 78 30 be 02 00 00 00 ff d2 eb
  RIP  [] shrink_page_list+0x24e/0x897
   RSP 
  CR2: 0000000000000028
  ---[ end trace 703d2451af6ffbfd ]---
  Kernel panic - not syncing: Fatal exception

This patch fixes the issue, by assuring the proper tests are made at
putback_movable_pages() & reclaim_clean_pages_from_list() to avoid
isolated balloon pages being wrongly reinserted in LRU lists.

[akpm@linux-foundation.org: clarify awkward comment text]
Signed-off-by: Rafael Aquini 
Reported-by: Luiz Capitulino 
Tested-by: Luiz Capitulino 
Cc: Mel Gorman 
Cc: Rik van Riel 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert "memcg, vmscan: integrate soft reclaim tighter with zone shrinking code"

2013-09-25T00:00:26+00:00

Revert commit 3b38722efd9f ("memcg, vmscan: integrate soft reclaim
tighter with zone shrinking code")

I merged this prematurely - Michal and Johannes still disagree about the
overall design direction and the future remains unclear.

Cc: Michal Hocko 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert "vmscan, memcg: do softlimit reclaim also for targeted reclaim"

2013-09-25T00:00:26+00:00

Revert commit a5b7c87f9207 ("vmscan, memcg: do softlimit reclaim also
for targeted reclaim")

I merged this prematurely - Michal and Johannes still disagree about the
overall design direction and the future remains unclear.

Cc: Michal Hocko 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert "memcg: enhance memcg iterator to support predicates"

2013-09-25T00:00:26+00:00

Revert commit de57780dc659 ("memcg: enhance memcg iterator to support
predicates")

I merged this prematurely - Michal and Johannes still disagree about the
overall design direction and the future remains unclear.

Cc: Michal Hocko 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert "memcg, vmscan: do not attempt soft limit reclaim if it would not scan anything"

2013-09-25T00:00:25+00:00

Revert commit e839b6a1c8d0 ("memcg, vmscan: do not attempt soft limit
reclaim if it would not scan anything")

I merged this prematurely - Michal and Johannes still disagree about the
overall design direction and the future remains unclear.

Cc: Michal Hocko 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert "memcg, vmscan: do not fall into reclaim-all pass too quickly"

2013-09-25T00:00:25+00:00

Revert commit e975de998b96 ("memcg, vmscan: do not fall into reclaim-all
pass too quickly")

I merged this prematurely - Michal and Johannes still disagree about the
overall design direction and the future remains unclear.

Cc: Michal Hocko 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patches from Andrew Morton)

2013-09-12T22:44:27+00:00

Merge more patches from Andrew Morton:
 "The rest of MM.  Plus one misc cleanup"

* emailed patches from Andrew Morton : (35 commits)
  mm/Kconfig: add MMU dependency for MIGRATION.
  kernel: replace strict_strto*() with kstrto*()
  mm, thp: count thp_fault_fallback anytime thp fault fails
  thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()
  thp: do_huge_pmd_anonymous_page() cleanup
  thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()
  mm: cleanup add_to_page_cache_locked()
  thp: account anon transparent huge pages into NR_ANON_PAGES
  truncate: drop 'oldsize' truncate_pagecache() parameter
  mm: make lru_add_drain_all() selective
  memcg: document cgroup dirty/writeback memory statistics
  memcg: add per cgroup writeback pages accounting
  memcg: check for proper lock held in mem_cgroup_update_page_stat
  memcg: remove MEMCG_NR_FILE_MAPPED
  memcg: reduce function dereference
  memcg: avoid overflow caused by PAGE_ALIGN
  memcg: rename RESOURCE_MAX to RES_COUNTER_MAX
  memcg: correct RESOURCE_MAX to ULLONG_MAX
  mm: memcg: do not trap chargers with full callstack on OOM
  mm: memcg: rework and document OOM waiting and wakeup
  ...

memcg: trivial cleanups

2013-09-12T22:38:01+00:00

Clean up some mess made by the "Soft limit rework" series, and a few other
things.

Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg, vmscan: do not fall into reclaim-all pass too quickly

2013-09-12T22:38:01+00:00

shrink_zone starts with soft reclaim pass first and then falls back to
regular reclaim if nothing has been scanned.  This behavior is natural
but there is a catch.  Memcg iterators, when used with the reclaim
cookie, are designed to help to prevent from over reclaim by
interleaving reclaimers (per node-zone-priority) so the tree walk might
miss many (even all) nodes in the hierarchy e.g.  when there are direct
reclaimers racing with each other or with kswapd in the global case or
multiple allocators reaching the limit for the target reclaim case.  To
make it even more complicated, targeted reclaim doesn't do the whole
tree walk because it stops reclaiming once it reclaims sufficient pages.
As a result groups over the limit might be missed, thus nothing is
scanned, and reclaim would fall back to the reclaim all mode.

This patch checks for the incomplete tree walk in shrink_zone.  If no
group has been visited and the hierarchy is soft reclaimable then we
must have missed some groups, in which case the __shrink_zone is called
again.  This doesn't guarantee there will be some progress of course
because the current reclaimer might be still racing with others but it
would at least give a chance to start the walk without a big risk of
reclaim latencies.

Signed-off-by: Michal Hocko 
Cc: Balbir Singh 
Cc: Glauber Costa 
Cc: Greg Thelen 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: KAMEZAWA Hiroyuki 
Cc: KOSAKI Motohiro 
Cc: Michel Lespinasse 
Cc: Tejun Heo 
Cc: Ying Han 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds