From: Michal Hocko <mhocko@kernel.org>
To: Ami Fischman <fischman@google.com>
Cc: Robert Kolchmeyer <rkolchmeyer@google.com>,
David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Vlastimil Babka <vbabka@suse.cz>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch] mm, oom: make a last minute check to prevent unnecessary memcg oom kills
Date: Wed, 18 Mar 2020 10:57:10 +0100 [thread overview]
Message-ID: <20200318095710.GG21362@dhcp22.suse.cz> (raw)
In-Reply-To: <CAHuR8a-PbmthrKYpY5-SM-MH39O39W2J1mXA48oy9nASmys0mg@mail.gmail.com>
On Tue 17-03-20 12:00:45, Ami Fischman wrote:
> On Tue, Mar 17, 2020 at 11:26 AM Robert Kolchmeyer
> <rkolchmeyer@google.com> wrote:
> >
> > On Tue, Mar 10, 2020 at 3:54 PM David Rientjes <rientjes@google.com> wrote:
> > >
> > > Robert, could you elaborate on the user-visible effects of this issue that
> > > caused it to initially get reported?
> >
> > Ami (now cc'ed) knows more, but here is my understanding.
>
> Robert's description of the mechanics we observed is accurate.
>
> We discovered this regression in the oom-killer's behavior when
> attempting to upgrade our system. The fraction of the system that
> went unhealthy due to this issue was approximately equal to the
> _sum_ of all other causes of unhealth, which are many and varied,
> but each of which contribute only a small amount of
> unhealth. This issue forced a rollback to the previous kernel
> where we ~never see this behavior, returning our unhealth levels
> to the previous background levels.
Could you be more specific on the good vs. bad kernel versions? Because
I do not remember any oom changes that would affect the
time-to-check-time-to-kill race. The timing might be slightly different
in each kernel version of course.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-03-18 9:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-10 21:55 [patch] mm, oom: make a last minute check to prevent unnecessary memcg oom kills David Rientjes
2020-03-10 22:19 ` Michal Hocko
2020-03-10 22:54 ` David Rientjes
2020-03-11 8:39 ` Michal Hocko
2020-03-17 7:59 ` Michal Hocko
2020-03-11 11:41 ` Tetsuo Handa
2020-03-11 19:51 ` David Rientjes
2020-03-17 18:25 ` Robert Kolchmeyer
2020-03-17 19:00 ` Ami Fischman
2020-03-18 9:57 ` Michal Hocko [this message]
2020-03-18 15:20 ` Ami Fischman
2020-03-18 9:55 ` Michal Hocko
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