Re: [PATCH] memcg: take reference before releasing rcu_read_lock

[Glauber Costa]

On 03/29/2013 02:28 PM, Li Zefan wrote:
> The memcg is not referenced, so it can be destroyed at anytime right
> after we exit rcu read section, so it's not safe to access it.
> 
> To fix this, we call css_tryget() to get a reference while we're still
> in rcu read section.
> 
> This also removes a bogus comment above __memcg_create_cache_enqueue().
> 
Out of curiosity, did you see that happening ?

Theoretically, the race you describe seem real, and the fix is sound.

Acked-by: Glauber Costa <glommer@xxxxxxxxxxxxx>
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