diff options
| author | KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> | 2009-01-07 18:08:13 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-08 08:31:07 -0800 |
| commit | a7fe942e94b2f66aa0f11d37699c0ec8155d3ad1 (patch) | |
| tree | 27525266a70f8bd9aadc45695ed8db220eaf2e9a | |
| parent | b85a96c0b6cb79c67e7b01b66368f2e31579d7c5 (diff) | |
memcg: swapout refcnt fix
css's refcnt is dropped before end of following access.
Hold it until end of access.
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memcontrol.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6ad309e9825f..964a70035e8f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1171,7 +1171,9 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype) mz = page_cgroup_zoneinfo(pc); unlock_page_cgroup(pc); - css_put(&mem->css); + /* at swapout, this memcg will be accessed to record to swap */ + if (ctype != MEM_CGROUP_CHARGE_TYPE_SWAPOUT) + css_put(&mem->css); return mem; @@ -1212,6 +1214,8 @@ void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent) swap_cgroup_record(ent, memcg); mem_cgroup_get(memcg); } + if (memcg) + css_put(&memcg->css); } #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP |