thp: transhuge-memcg: commit tail pages at charge
authorDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Thu, 13 Jan 2011 23:46:56 +0000 (15:46 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 14 Jan 2011 01:32:43 +0000 (17:32 -0800)
commit152c9ccb75548c027fa3103efa4fa4e19a345449
treed22e8f71b3e0689fc0e3ae21609ae1abe5bc4d2f
parentec1685109f1314a30919489ef2800ed626a38c1e
thp: transhuge-memcg: commit tail pages at charge

By this patch, when a transparent hugepage is charged, not only the head
page but also all the tail pages are committed, IOW pc->mem_cgroup and
pc->flags of tail pages are set.

Without this patch:

- Tail pages are not linked to any memcg's LRU at splitting. This causes many
  problems, for example, the charged memcg's directory can never be rmdir'ed
  because it doesn't have enough pages to scan to make the usage decrease to 0.
- "rss" field in memory.stat would be incorrect. Moreover, usage_in_bytes in
  root cgroup is calculated by the stat not by res_counter(since 2.6.32),
  it would be incorrect too.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/memcontrol.c