From: Yafang Shao <laoar.shao@gmail.com>
To: Chris Down <chris@chrisdown.name>
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 09:49:46 +0800 [thread overview]
Message-ID: <CALOAHbAzZUwGq3mnEtOcSetvAAm+m=X_KnQ2eS9U0QQVHggWYg@mail.gmail.com> (raw)
In-Reply-To: <20200430014603.GB2754277@chrisdown.name>
On Thu, Apr 30, 2020 at 9:46 AM Chris Down <chris@chrisdown.name> wrote:
>
> 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.
Thanks for your suggestion.
I'm planning to add these barriers all over the memory cgroup code.
--
Thanks
Yafang
next prev parent reply other threads:[~2020-04-30 1:50 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
2020-04-30 1:49 ` Yafang Shao [this message]
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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