Re: [PATCH 0/3] OOM detection rework v4

From	Michal Hocko <mhocko@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 0/3] OOM detection rework v4
Date	2015-12-29 17:40 +0100
Message-ID	<qL5tw-2Yw-3@gated-at.bofh.it> (permalink)
References	<qG2wi-7PJ-13@gated-at.bofh.it> <qJdvd-6KI-35@gated-at.bofh.it> <qKEMH-1Ku-27@gated-at.bofh.it>
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On Mon 28-12-15 21:08:56, Tetsuo Handa wrote:
> Tetsuo Handa wrote:
> > I got OOM killers while running heavy disk I/O (extracting kernel source,
> > running lxr's genxref command). (Environ: 4 CPUs / 2048MB RAM / no swap / XFS)
> > Do you think these OOM killers reasonable? Too weak against fragmentation?
> 
> Well, current patch invokes OOM killers when more than 75% of memory is used
> for file cache (active_file: + inactive_file:). I think this is a surprising
> thing for administrators and we want to retry more harder (but not forever,
> please).

Here again, it would be good to see what is the comparision between
the original and the new behavior. 75% of a page cache is certainly
unexpected but those pages might be pinned for other reasons and so
unreclaimable and basically IO bound. This is hard to optimize for
without causing any undesirable side effects for other loads. I will
have a look at the oom reports later but having a comparision would be
a great start.

Thanks!
-- 
Michal Hocko
SUSE Labs
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Thread

[PATCH 0/3] OOM detection rework v4 Michal Hocko <mhocko@kernel.org> - 2015-12-15 19:30 +0100
  [PATCH 2/3] mm: throttle on IO only when there are too many dirty and writeback pages Michal Hocko <mhocko@kernel.org> - 2015-12-15 19:30 +0100
  [PATCH 1/3] mm, oom: rework oom detection Michal Hocko <mhocko@kernel.org> - 2015-12-15 19:30 +0100
  Re: [PATCH 0/3] OOM detection rework v4 Andrew Morton <akpm@linux-foundation.org> - 2015-12-17 00:40 +0100
    Re: [PATCH 0/3] OOM detection rework v4 Michal Hocko <mhocko@kernel.org> - 2015-12-18 13:20 +0100
  Re: [PATCH 0/3] OOM detection rework v4 Andrew Morton <akpm@linux-foundation.org> - 2015-12-17 01:00 +0100
    Re: [PATCH 0/3] OOM detection rework v4 Michal Hocko <mhocko@kernel.org> - 2015-12-18 14:20 +0100
      Re: [PATCH 0/3] OOM detection rework v4 Johannes Weiner <hannes@cmpxchg.org> - 2015-12-18 17:40 +0100
  Re: [PATCH 0/3] OOM detection rework v4 Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-12-24 13:50 +0100
    Re: [PATCH 0/3] OOM detection rework v4 Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-12-28 13:10 +0100
      Re: [PATCH 0/3] OOM detection rework v4 Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-12-28 15:20 +0100
      Re: [PATCH 0/3] OOM detection rework v4 Michal Hocko <mhocko@kernel.org> - 2015-12-29 17:40 +0100
        Re: [PATCH 0/3] OOM detection rework v4 Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2015-12-30 16:10 +0100
    Re: [PATCH 0/3] OOM detection rework v4 Michal Hocko <mhocko@kernel.org> - 2015-12-29 17:30 +0100

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