Date: Fri, 7 Oct 2016 14:14:01 +0900
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: Doug Smythies <dsmythies@telus.net>
Cc: "'Andrew Morton'" <akpm@linux-foundation.org>,
        "'Christoph Lameter'" <cl@linux.com>,
        "'Pekka Enberg'" <penberg@kernel.org>,
        "'David Rientjes'" <rientjes@google.com>,
        "'Johannes Weiner'" <hannes@cmpxchg.org>,
        "'Vladimir Davydov'" <vdavydov.dev@gmail.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] mm/slab: fix kmemcg cache creation delayed issue
Message-ID: <20161007051400.GA7294@js1304-P5Q-DELUXE>
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On Thu, Oct 06, 2016 at 09:02:00AM -0700, Doug Smythies wrote:
> It was my (limited) understanding that the subsequent 2 patch set
> superseded this patch. Indeed, the 2 patch set seems to solve
> both the SLAB and SLUB bug reports.

It would mean that patch 1 solves both the SLAB and SLUB bug reports
since patch 2 is only effective for SLUB.

Reason that I send this patch is that although patch 1 fixes the
issue that too many kworkers are created, kmem_cache creation/destory
is still slowed by synchronize_sched() and it would cause kmemcg
usage counting delayed. I'm not sure how bad it is but it's generally
better to start accounting as soon as possible. With patch 2 for SLUB
and this patch for SLAB, performance of kmem_cache
creation/destory would recover.

Thanks.

> 
> References:
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=172981
> https://bugzilla.kernel.org/show_bug.cgi?id=172991
> https://patchwork.kernel.org/patch/9361853
> https://patchwork.kernel.org/patch/9359271