[Devel] [PATCH 3/8] memcg, slab: never try to merge memcg caches

[Michal Hocko]

On Thu 06-02-14 18:15:50, Vladimir Davydov wrote:
> On 02/06/2014 06:07 PM, Michal Hocko wrote:
> > On Tue 04-02-14 19:27:19, Vladimir Davydov wrote:
> > [...]
> >> What does this patch change? Actually, it introduces no functional
> >> changes - it only remove the code trying to find an alias for a memcg
> >> cache, because it will fail anyway. So this is rather a cleanup.
> > But this also means that two different memcgs might share the same cache
> > and so the pages for that cache, no?
> 
> No, because in this patch I explicitly forbid to merge memcg caches by
> this hunk:
> 
> @@ -200,9 +200,11 @@ kmem_cache_create_memcg(struct mem_cgroup *memcg,
> const char *name, size_t size,
>       */
>      flags &= CACHE_CREATE_MASK;
>  
> -    s = __kmem_cache_alias(memcg, name, size, align, flags, ctor);
> -    if (s)
> -        goto out_unlock;
> +    if (!memcg) {
> +        s = __kmem_cache_alias(name, size, align, flags, ctor);
> +        if (s)
> +            goto out_unlock;
> +    }

Ohh, that was the missing part. Thanks and sorry I have missed it. Maybe
it is worth mentioning in the changelog?
-- 
Michal Hocko
SUSE Labs