Messages in this thread | | | Date | Fri, 21 Nov 2008 19:32:10 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH] memcontrol: rcu_read_lock() to protect mm_match_cgroup() |
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On Fri, 21 Nov 2008 16:49:43 +0800 Lai Jiangshan <laijs@cn.fujitsu.com> wrote:
> > mm_match_cgroup() calls cgroup_subsys_state(). > > we must use rcu_read_lock() to protect cgroup_subsys_state(). > Thanks, Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> 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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