Re: [PATCH 9/9] slab: remove slub sysfs interface files early for empty memcg caches

Vladimir Davydov
2017-01-14T14:00:43Z

On Sat, Jan 14, 2017 at 12:54:49AM -0500, Tejun Heo wrote:
> With kmem cgroup support enabled, kmem_caches can be created and
> destroyed frequently and a great number of near empty kmem_caches can
> accumulate if there are a lot of transient cgroups and the system is
> not under memory pressure. When memory reclaim starts under such
> conditions, it can lead to consecutive deactivation and destruction of
> many kmem_caches, easily hundreds of thousands on moderately large
> systems, exposing scalability issues in the current slab management
> code. This is one of the patches to address the issue.
>
> Each cache has a number of sysfs interface files under
> /sys/kernel/slab. On a system with a lot of memory and transient
> memcgs, the number of interface files which have to be removed once
> memory reclaim kicks in can reach millions.
>
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Reported-by: Jay Vana <jsvana@fb.com>
> Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
> Cc: Christoph Lameter <cl@linux.com>
> Cc: Pekka Enberg <penberg@kernel.org>
> Cc: David Rientjes <rientjes@google.com>
> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>

Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>