From: Michal Hocko <mhocko@kernel.org>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-team@fb.com, Andy Lutomirski <luto@kernel.org>,
Konstantin Khlebnikov <koct9i@gmail.com>,
Tejun Heo <tj@kernel.org>
Subject: Re: [RFC PATCH 1/2] mm: rework memcg kernel stack accounting
Date: Thu, 16 Aug 2018 08:35:09 +0200 [thread overview]
Message-ID: <20180816063509.GS32645@dhcp22.suse.cz> (raw)
In-Reply-To: <20180815172044.GA29793@cmpxchg.org>
On Wed 15-08-18 13:20:44, Johannes Weiner wrote:
[...]
> This is completely backwards.
>
> We respect the limits unless there is a *really* strong reason not
> to. The only situations I can think of is during OOM kills to avoid
> memory deadlocks and during packet reception for correctness issues
> (and because the network stack has its own way to reclaim memory).
>
> Relying on some vague future allocations in the process's lifetime to
> fail in order to contain it is crappy and unreliable. And unwinding
> the stack allocation isn't too much complexity to warrant breaking the
> containment rules here, even if it were several steps. But it looks
> like it's nothing more than a 'goto free_stack'.
>
> Please just fix this.
Thinking about it some more (sorry I should have done that in my
previous reply already) I do agree with Johannes. We should really back
off as soon as possible rather than rely on a future action because
this is quite subtle and prone to unexpected behavior.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-08-16 6:35 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-15 0:36 [RFC PATCH 1/2] mm: rework memcg kernel stack accounting Roman Gushchin
2018-08-15 0:36 ` [RFC PATCH 2/2] mm: drain memcg stocks on css offlining Roman Gushchin
2018-08-15 0:54 ` Shakeel Butt
2018-08-15 7:29 ` Michal Hocko
2018-08-15 1:18 ` [RFC PATCH 1/2] mm: rework memcg kernel stack accounting Shakeel Butt
2018-08-15 17:16 ` Roman Gushchin
2018-08-15 7:10 ` Michal Hocko
2018-08-15 16:39 ` Johannes Weiner
2018-08-15 16:55 ` Roman Gushchin
2018-08-15 17:12 ` Andy Lutomirski
2018-08-15 17:25 ` Roman Gushchin
2018-08-15 17:32 ` Shakeel Butt
2018-08-15 17:37 ` Andy Lutomirski
2018-08-21 17:22 ` Roman Gushchin
2018-08-15 17:20 ` Johannes Weiner
2018-08-16 6:35 ` Michal Hocko [this message]
2018-08-16 15:24 ` Roman Gushchin
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