From: Johannes Weiner <hannes@cmpxchg.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
"Vladimir Davydov" <vdavydov.dev@gmail.com>,
"Marek Marczykowski-Górecki" <marmarek@mimuw.edu.pl>,
"Balbir Singh" <bsingharora@gmail.com>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] mm: workingset: fix NULL ptr in count_shadow_nodes
Date: Thu, 1 Dec 2016 16:07:15 -0500 [thread overview]
Message-ID: <20161201210715.GA21302@cmpxchg.org> (raw)
In-Reply-To: <20161201132156.21450-1-mhocko@kernel.org>
On Thu, Dec 01, 2016 at 02:21:56PM +0100, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware")
> has made the workingset shadow nodes shrinker memcg aware. The
> implementation is not correct though because memcg_kmem_enabled() might
> become true while we are doing a global reclaim when the sc->memcg might
> be NULL which is exactly what Marek has seen:
[...]
> This patch fixes the issue by checking sc->memcg rather than memcg_kmem_enabled()
> which is sufficient because shrink_slab makes sure that only memcg aware shrinkers
> will get non-NULL memcgs and only if memcg_kmem_enabled is true.
>
> Fixes: 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware")
> Reported-and-tested-by: Marek Marczykowski-Gorecki <marmarek@mimuw.edu.pl>
> Cc: stable@vger.kernel.org # 4.6+
> Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Thanks Michal
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-12-01 21:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-01 13:21 [PATCH] mm: workingset: fix NULL ptr in count_shadow_nodes Michal Hocko
2016-12-01 13:32 ` Vladimir Davydov
2016-12-01 21:07 ` Johannes Weiner [this message]
2016-12-01 21:24 ` Balbir Singh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161201210715.GA21302@cmpxchg.org \
--to=hannes@cmpxchg.org \
--cc=akpm@linux-foundation.org \
--cc=bsingharora@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=marmarek@mimuw.edu.pl \
--cc=mhocko@kernel.org \
--cc=vdavydov.dev@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).