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* [PATCH] memcontrol: rcu_read_lock() to protect mm_match_cgroup()
@ 2008-11-21  8:49 Lai Jiangshan
  2008-11-21 10:32 ` KAMEZAWA Hiroyuki
  0 siblings, 1 reply; 2+ messages in thread
From: Lai Jiangshan @ 2008-11-21  8:49 UTC (permalink / raw)
  To: Andrew Morton, Paul Menage, Linux Kernel Mailing List,
	Linux Containers, KAMEZAWA Hiroyuki


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);


^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] memcontrol: rcu_read_lock() to protect mm_match_cgroup()
  2008-11-21  8:49 [PATCH] memcontrol: rcu_read_lock() to protect mm_match_cgroup() Lai Jiangshan
@ 2008-11-21 10:32 ` KAMEZAWA Hiroyuki
  0 siblings, 0 replies; 2+ messages in thread
From: KAMEZAWA Hiroyuki @ 2008-11-21 10:32 UTC (permalink / raw)
  To: Lai Jiangshan
  Cc: Andrew Morton, Paul Menage, Linux Kernel Mailing List, Linux Containers

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);
> 
> 


^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2008-11-21 10:33 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
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2008-11-21  8:49 [PATCH] memcontrol: rcu_read_lock() to protect mm_match_cgroup() Lai Jiangshan
2008-11-21 10:32 ` KAMEZAWA Hiroyuki

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