Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about stalls

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From	Shakeel Butt <shakeelb@google.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about stalls
Date	Wed, 13 Sep 2017 17:00:02 +0200
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X-Original-Cc	Mikulas Patocka <mpatocka@redhat.com>, Michal Hocko <mhocko@kernel.org>, Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>, Johannes Weiner <hannes@cmpxchg.org>, Mel Gorman <mgorman@suse.de>, Dave Hansen <dave.hansen@intel.com>, Andrew Morton <akpm@linux-foundation.org>, Linux MM <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>
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>
> We would have to consider (instead of jiffies) the time the process was
> either running, or waiting on something that's related to memory
> allocation/reclaim (page lock etc.). I.e. deduct the time the process
> was runable but there was no available cpu. I expect however that such
> level of detail wouldn't be feasible here, though?
>

Johannes' memdelay work (once merged) might be useful here. I think
memdalay can differentiate between an allocating process getting
delayed due to preemption or due to unsuccessful reclaim/compaction.
If the delay is due to unsuccessful reclaim/compaction then we should
warn here.

Thread

[PATCH] mm: respect the __GFP_NOWARN flag when warning about  stalls Mikulas Patocka <mpatocka@redhat.com> - 2017-09-11 09:00 +0200
  Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about  stalls Michal Hocko <mhocko@kernel.org> - 2017-09-11 10:30 +0200
    Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about  stalls Mikulas Patocka <mpatocka@redhat.com> - 2017-09-12 01:40 +0200
      Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about  stalls Vlastimil Babka <vbabka@suse.cz> - 2017-09-12 09:20 +0200
        Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about stalls Shakeel Butt <shakeelb@google.com> - 2017-09-13 17:00 +0200
      Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about  stalls Michal Hocko <mhocko@kernel.org> - 2017-09-13 14:00 +0200
        Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about stalls Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-09-13 16:00 +0200
          Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about  stalls Vlastimil Babka <vbabka@suse.cz> - 2017-09-13 16:10 +0200
            Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about stalls Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-09-13 16:20 +0200
              Re: [PATCH] mm: respect the __GFP_NOWARN flag when warning about  stalls Michal Hocko <mhocko@kernel.org> - 2017-09-13 16:40 +0200

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