From: Chris Down <chris@chrisdown.name>
To: Yafang Shao <laoar.shao@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>, Roman Gushchin <guro@fb.com>,
Linux MM <linux-mm@kvack.org>, Cgroups <cgroups@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] mm, memcg: Avoid stale protection values when cgroup is above protection
Date: Thu, 30 Apr 2020 02:46:03 +0100 [thread overview]
Message-ID: <20200430014603.GB2754277@chrisdown.name> (raw)
In-Reply-To: <CALOAHbCL_JJgcy9r99Kn81-o_t-fs_nQ+n7aKMHO-02QMCufEw@mail.gmail.com>
Yafang Shao writes:
>My concern is why we add these barriers to memcg protection
>specifically but don't add these barriers to the other memebers like
>memcg->oom_group which has the same issue ?
>What is the difference between these members and that members ?
There are certainly more missing cases -- I didn't look at oom_group
specifically, but it sounds likely if there's not other mitigating factors.
Most of us have just been busy and haven't had time to comprehensively fix all
the potential store and load tears.
Tearing is another case of something that would be nice to fix once and for all
in the memcg code, but isn't causing any significant issues for the timebeing.
We should certainly aim to avoid introducing any new tearing opportunities,
though :-)
So the answer is just that improvement is incremental and we've not had the
time to track down and fix them all. If you find more cases, feel free to send
out the patches and I'll be happy to take a look.
next prev parent reply other threads:[~2020-04-30 1:46 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 18:26 [PATCH 0/2] mm: memcontrol: memory.{low,min} reclaim fix & cleanup Chris Down
2020-04-28 18:26 ` [PATCH 1/2] mm, memcg: Avoid stale protection values when cgroup is above protection Chris Down
2020-04-28 21:16 ` Johannes Weiner
2020-04-29 10:15 ` Michal Hocko
2020-04-29 10:53 ` Yafang Shao
2020-04-29 14:19 ` Johannes Weiner
2020-04-29 14:03 ` Johannes Weiner
2020-04-29 14:17 ` Yafang Shao
2020-04-29 14:27 ` Johannes Weiner
2020-04-29 14:31 ` Yafang Shao
2020-04-29 15:04 ` Michal Hocko
2020-04-29 16:56 ` Johannes Weiner
2020-04-30 14:57 ` Michal Hocko
2020-04-30 17:17 ` Roman Gushchin
2020-04-30 23:59 ` Yafang Shao
2020-05-04 7:23 ` Michal Hocko
2020-05-04 22:59 ` Roman Gushchin
2020-04-30 1:04 ` Yafang Shao
2020-04-30 1:16 ` Chris Down
2020-04-30 1:31 ` Yafang Shao
2020-04-30 1:46 ` Chris Down [this message]
2020-04-30 1:49 ` Yafang Shao
2020-04-28 18:27 ` [PATCH 2/2] mm, memcg: Decouple e{low,min} state mutations from protection checks Chris Down
2020-04-28 21:19 ` Johannes Weiner
2020-04-29 10:06 ` Michal Hocko
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