linux-stable.git/mm/memcontrol.c, branch v3.6

memcg: add mem_cgroup_from_css() helper

2012-08-01T01:42:49+00:00

Add a mem_cgroup_from_css() helper to replace open-coded invokations of
container_of().  To clarify the code and to add a little more type safety.

[akpm@linux-foundation.org: fix extensive breakage]
Signed-off-by: Wanpeng Li 
Acked-by: Michal Hocko 
Cc: Johannes Weiner 
Cc: KAMEZAWA Hiroyuki 
Cc: Gavin Shan 
Cc: Wanpeng Li 
Cc: Gavin Shan 
Cc: Johannes Weiner 
Cc: KAMEZAWA Hiroyuki 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: only check anon swapin page charges for swap cache

2012-08-01T01:42:49+00:00

shmem knows for sure that the page is in swap cache when attempting to
charge a page, because the cache charge entry function has a check for it.
Only anon pages may be removed from swap cache already when trying to
charge their swapin.

Adjust the comment, though: '4969c11 mm: fix swapin race condition' added
a stable PageSwapCache check under the page lock in the do_swap_page()
before calling the memory controller, so it's unuse_pte()'s pte_same()
that may fail.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: only check swap cache pages for repeated charging

2012-08-01T01:42:49+00:00

Only anon and shmem pages in the swap cache are attempted to be charged
multiple times, from every swap pte fault or from shmem_unuse().  No other
pages require checking PageCgroupUsed().

Charging pages in the swap cache is also serialized by the page lock, and
since both the try_charge and commit_charge are called under the same page
lock section, the PageCgroupUsed() check might as well happen before the
counter charging, let alone reclaim.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: split swapin charge function into private and public part

2012-08-01T01:42:48+00:00

When shmem is charged upon swapin, it does not need to check twice whether
the memory controller is enabled.

Also, shmem pages do not have to be checked for everything that regular
anon pages have to be checked for, so let shmem use the internal version
directly and allow future patches to move around checks that are only
required when swapping in anon pages.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: remove needless !mm fixup to init_mm when charging

2012-08-01T01:42:48+00:00

It does not matter to __mem_cgroup_try_charge() if the passed mm is NULL
or init_mm, it will charge the root memcg in either case.

Also fix up the comment in __mem_cgroup_try_charge() that claimed the
init_mm would be charged when no mm was passed.  It's not really
incorrect, but confusing.  Clarify that the root memcg is charged in this
case.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: remove unneeded shmem charge type

2012-08-01T01:42:48+00:00

shmem page charges have not needed a separate charge type to tell them
from regular file pages since 08e552c ("memcg: synchronized LRU").

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: move swapin charge functions above callsites

2012-08-01T01:42:48+00:00

Charging cache pages may require swapin in the shmem case.  Save the
forward declaration and just move the swapin functions above the cache
charging functions.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: only check for PageSwapCache when uncharging anon

2012-08-01T01:42:48+00:00

Only anon pages that are uncharged at the time of the last page table
mapping vanishing may be in swapcache.

When shmem pages, file pages, swap-freed anon pages, or just migrated
pages are uncharged, they are known for sure to be not in swapcache.

Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: push down PageSwapCache check into uncharge entry functions

2012-08-01T01:42:48+00:00

Not all uncharge paths need to check if the page is swapcache, some of
them can know for sure.

Push down the check into all callsites of uncharge_common() so that the
patch that removes some of them is more obvious.

Signed-off-by: Johannes Weiner 
Acked-by: Michal Hocko 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: memcg: fix compaction/migration failing due to memcg limits

2012-08-01T01:42:48+00:00

Compaction (and page migration in general) can currently be hindered
through pages being owned by memory cgroups that are at their limits and
unreclaimable.

The reason is that the replacement page is being charged against the limit
while the page being replaced is also still charged.  But this seems
unnecessary, given that only one of the two pages will still be in use
after migration finishes.

This patch changes the memcg migration sequence so that the replacement
page is not charged.  Whatever page is still in use after successful or
failed migration gets to keep the charge of the page that was going to be
replaced.

The replacement page will still show up temporarily in the rss/cache
statistics, this can be fixed in a later patch as it's less urgent.

Reported-by: David Rientjes 
Signed-off-by: Johannes Weiner 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Michal Hocko 
Cc: Hugh Dickins 
Cc: David Rientjes 
Cc: Wanpeng Li 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds