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

From	Johannes Weiner <hannes@cmpxchg.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 0/3] OOM detection rework v4
Date	2015-12-18 17:40 +0100
Message-ID	<qH6et-82w-5@gated-at.bofh.it> (permalink)
References	<qG2wi-7PJ-13@gated-at.bofh.it> <qGu9c-8tX-7@gated-at.bofh.it> <qH36W-682-3@gated-at.bofh.it>
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On Fri, Dec 18, 2015 at 02:15:09PM +0100, Michal Hocko wrote:
> On Wed 16-12-15 15:58:44, Andrew Morton wrote:
> > It's hard to say how long declaration of oom should take.  Correctness
> > comes first.  But what is "correct"?  oom isn't a binary condition -
> > there's a chance that if we keep churning away for another 5 minutes
> > we'll be able to satisfy this allocation (but probably not the next
> > one).  There are tradeoffs between promptness-of-declaring-oom and
> > exhaustiveness-in-avoiding-it.
> 
> Yes, this is really hard to tell. What I wanted to achieve here is a
> determinism - the same load should give comparable results. It seems
> that there is an improvement in this regards. The time to settle is 
> much more consistent than with the original implementation.

+1

Before that we couldn't even really make a meaningful statement about
how long we are going to try - "as long as reclaim thinks it can maybe
do some more, depending on heuristics". I think the best thing we can
strive for with OOM is to make the rules simple and predictable.
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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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