linux-kernel - Re: [PATCH 2/2] slub: move synchronize_sched out of slab

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Date:   Thu, 6 Oct 2016 15:27:08 +0900
From:   Joonsoo Kim <iamjoonsoo.kim@....com>
To:     Vladimir Davydov <vdavydov.dev@...il.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, Christoph Lameter <cl@...ux.com>,
        David Rientjes <rientjes@...gle.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Michal Hocko <mhocko@...nel.org>,
        Pekka Enberg <penberg@...nel.org>,
        Doug Smythies <dsmythies@...us.net>
Subject: Re: [PATCH 2/2] slub: move synchronize_sched out of slab_mutex on
 shrink

Ccing Doug, original reporter.

On Sat, Oct 01, 2016 at 04:56:48PM +0300, Vladimir Davydov wrote:
> synchronize_sched() is a heavy operation and calling it per each cache
> owned by a memory cgroup being destroyed may take quite some time. What
> is worse, it's currently called under the slab_mutex, stalling all works
> doing cache creation/destruction.
> 
> Actually, there isn't much point in calling synchronize_sched() for each
> cache - it's enough to call it just once - after setting cpu_partial for
> all caches and before shrinking them. This way, we can also move it out
> of the slab_mutex, which we have to hold for iterating over the slab
> cache list.
> 
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=172991
> Signed-off-by: Vladimir Davydov <vdavydov.dev@...il.com>
> Reported-by: Doug Smythies <dsmythies@...us.net>
> Cc: Christoph Lameter <cl@...ux.com>
> Cc: David Rientjes <rientjes@...gle.com>
> Cc: Johannes Weiner <hannes@...xchg.org>
> Cc: Joonsoo Kim <iamjoonsoo.kim@....com>
> Cc: Michal Hocko <mhocko@...nel.org>
> Cc: Pekka Enberg <penberg@...nel.org>

Acked-by: Joonsoo Kim <iamjoonsoo.kim@....com>

These two patches should be sent to stable. Isn't it?

Thanks.