diff options
| author | Balbir Singh <balbir@linux.vnet.ibm.com> | 2008-02-07 09:14:18 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-07 17:42:20 +0100 |
| commit | ac44d354d5c9ced49b1165d6496f134501134219 (patch) | |
| tree | be054e8e2d37739a33d94cc78db3fd65e73c3aff /mm | |
| parent | memory cgroup enhancements: remember "a page is charged as page cache" (diff) | |
| download | linux-ac44d354d5c9ced49b1165d6496f134501134219.tar.xz linux-ac44d354d5c9ced49b1165d6496f134501134219.zip | |
Memory controller use rcu_read_lock() in mem_cgroup_cache_charge()
Hugh Dickins noticed that we were using rcu_dereference() without
rcu_read_lock() in the cache charging routine. The patch below fixes
this problem
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 975e89935d52..160101a05b4d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -456,16 +456,20 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm, int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask) { + int ret = 0; struct mem_cgroup *mem; if (!mm) mm = &init_mm; + rcu_read_lock(); mem = rcu_dereference(mm->mem_cgroup); + css_get(&mem->css); + rcu_read_unlock(); if (mem->control_type == MEM_CGROUP_TYPE_ALL) - return mem_cgroup_charge_common(page, mm, gfp_mask, + ret = mem_cgroup_charge_common(page, mm, gfp_mask, MEM_CGROUP_CHARGE_TYPE_CACHE); - else - return 0; + css_put(&mem->css); + return ret; } /* |