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From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Mel Gorman <mgorman@suse.de>,
	David Rientjes <rientjes@google.com>, <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 0/2] GFP_NOFAIL cleanups
Date: Thu,  1 Dec 2016 16:25:15 +0100	[thread overview]
Message-ID: <20161201152517.27698-1-mhocko@kernel.org> (raw)

Hi,
I have posted this as an RFC previously [1] as there was no fundamental
disagreement I would like to ask for inclusion.

Tetsuo has noticed [2] that recent changes have changed GFP_NOFAIL
semantic for costly order requests. I believe that the primary reason
why this happened is that our GFP_NOFAIL checks are too scattered
and it is really easy to forget about adding one. That's why I am
proposing patch 1 which consolidates all the nofail handling at a single
place. This should help to make this code better maintainable.

Patch 2 on top is a further attempt to make GFP_NOFAIL semantic less
surprising. As things stand currently GFP_NOFAIL overrides the oom killer
prevention code which is both subtle and not really needed. The patch 2
has more details about issues this might cause.

I would consider both patches more a cleanup than anything else. Any
feedback is highly appreciated.

[1] http://lkml.kernel.org/r/20161123064925.9716-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/1479387004-5998-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp

WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Mel Gorman <mgorman@suse.de>,
	David Rientjes <rientjes@google.com>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH 0/2] GFP_NOFAIL cleanups
Date: Thu,  1 Dec 2016 16:25:15 +0100	[thread overview]
Message-ID: <20161201152517.27698-1-mhocko@kernel.org> (raw)

Hi,
I have posted this as an RFC previously [1] as there was no fundamental
disagreement I would like to ask for inclusion.

Tetsuo has noticed [2] that recent changes have changed GFP_NOFAIL
semantic for costly order requests. I believe that the primary reason
why this happened is that our GFP_NOFAIL checks are too scattered
and it is really easy to forget about adding one. That's why I am
proposing patch 1 which consolidates all the nofail handling at a single
place. This should help to make this code better maintainable.

Patch 2 on top is a further attempt to make GFP_NOFAIL semantic less
surprising. As things stand currently GFP_NOFAIL overrides the oom killer
prevention code which is both subtle and not really needed. The patch 2
has more details about issues this might cause.

I would consider both patches more a cleanup than anything else. Any
feedback is highly appreciated.

[1] http://lkml.kernel.org/r/20161123064925.9716-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/1479387004-5998-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp

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             reply	other threads:[~2016-12-01 15:25 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-01 15:25 Michal Hocko [this message]
2016-12-01 15:25 ` [PATCH 0/2] GFP_NOFAIL cleanups Michal Hocko
2016-12-01 15:25 ` [PATCH 1/2] mm: consolidate GFP_NOFAIL checks in the allocator slowpath Michal Hocko
2016-12-01 15:25   ` Michal Hocko
2016-12-01 15:25 ` [PATCH 2/2] mm, oom: do not enfore OOM killer for __GFP_NOFAIL automatically Michal Hocko
2016-12-01 15:25   ` Michal Hocko
2016-12-02  7:23   ` Vlastimil Babka
2016-12-02  7:23     ` Vlastimil Babka
2016-12-05 13:45   ` Tetsuo Handa
2016-12-05 13:45     ` Tetsuo Handa
2016-12-05 14:10     ` Michal Hocko
2016-12-05 14:10       ` Michal Hocko
2016-12-06  8:27       ` Michal Hocko
2016-12-06  8:27         ` Michal Hocko
2016-12-06 10:38       ` Tetsuo Handa
2016-12-06 10:38         ` Tetsuo Handa
2016-12-06 11:03         ` Vlastimil Babka
2016-12-06 11:03           ` Vlastimil Babka
2016-12-06 19:25           ` Michal Hocko
2016-12-06 19:25             ` Michal Hocko
2016-12-06 19:22         ` Michal Hocko
2016-12-06 19:22           ` Michal Hocko
2016-12-08 12:53           ` Tetsuo Handa
2016-12-08 12:53             ` Tetsuo Handa
2016-12-08 13:47             ` Michal Hocko
2016-12-08 13:47               ` Michal Hocko
2016-12-11 11:23               ` Tetsuo Handa
2016-12-11 11:23                 ` Tetsuo Handa
2016-12-11 13:53                 ` Tetsuo Handa
2016-12-11 13:53                   ` Tetsuo Handa
2016-12-12  8:52                   ` Michal Hocko
2016-12-12  8:52                     ` Michal Hocko
2016-12-12  8:48                 ` Michal Hocko
2016-12-12  8:48                   ` Michal Hocko
2016-12-14 10:34                   ` Michal Hocko
2016-12-14 10:34                     ` Michal Hocko

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