Re: [PATCH] memcg: fix oops in mem_cgroup_shrink_usage

[Balbir Singh <balbir@linux.vnet.ibm.com>]

Hugh Dickins wrote:
> Got an oops in mem_cgroup_shrink_usage() when testing loop over tmpfs:
> yes, of course, loop0 has no mm: other entry points check but this didn't.
> 
> Signed-off-by: Hugh Dickins <hugh@veritas.com>
> ---
> 
>  mm/memcontrol.c |    2 ++
>  1 file changed, 2 insertions(+)
> 
> --- 2.6.27-rc2/mm/memcontrol.c	2008-08-06 08:36:20.000000000 +0100
> +++ linux/mm/memcontrol.c	2008-08-06 09:05:26.000000000 +0100
> @@ -796,6 +796,8 @@ int mem_cgroup_shrink_usage(struct mm_st
> 
>  	if (mem_cgroup_subsys.disabled)
>  		return 0;
> +	if (!mm)
> +		return 0;
> 
>  	rcu_read_lock();
>  	mem = mem_cgroup_from_task(rcu_dereference(mm->owner));

Looks good

Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>



-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL