Messages in this thread Patch in this message | | | Date | Fri, 21 Nov 2008 16:49:43 +0800 | From | Lai Jiangshan <> | Subject | [PATCH] memcontrol: rcu_read_lock() to protect mm_match_cgroup() |
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mm_match_cgroup() calls cgroup_subsys_state().
we must use rcu_read_lock() to protect cgroup_subsys_state().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 1fbe14d..ce89ff0 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -47,8 +47,15 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem); extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p); -#define mm_match_cgroup(mm, cgroup) \ - ((cgroup) == mem_cgroup_from_task((mm)->owner)) +static inline +int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup) +{ + struct mem_cgroup *mem; + rcu_read_lock(); + mem = mem_cgroup_from_task((mm)->owner); + rcu_read_unlock(); + return cgroup == mem; +} extern int mem_cgroup_prepare_migration(struct page *page, struct page *newpage);
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