From: Vlastimil Babka <vbabka@suse.cz>
To: Joonsoo Kim <iamjoonsoo.kim@lge.com>, Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Mel Gorman <mgorman@suse.de>,
David Rientjes <rientjes@google.com>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
Hillf Danton <hillf.zj@alibaba-inc.com>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0.14] oom detection rework v6
Date: Wed, 4 May 2016 10:12:43 +0200 [thread overview]
Message-ID: <5729AEFB.9060101@suse.cz> (raw)
In-Reply-To: <20160504054502.GA10899@js1304-P5Q-DELUXE>
On 05/04/2016 07:45 AM, Joonsoo Kim wrote:
> I still don't agree with some part of this patchset that deal with
> !costly order. As you know, there was two regression reports from Hugh
> and Aaron and you fixed them by ensuring to trigger compaction. I
> think that these show the problem of this patchset. Previous kernel
> doesn't need to ensure to trigger compaction and just works fine in
> any case.
IIRC previous kernel somehow subtly never OOM'd for !costly orders. So
anything that introduces the possibility of OOM may look like regression
for some corner case workloads. But I don't think that it's OK to not
OOM for e.g. kernel stack allocations?
> Your series make compaction necessary for all. OOM handling
> is essential part in MM but compaction isn't. OOM handling should not
> depend on compaction. I tested my own benchmark without
> CONFIG_COMPACTION and found that premature OOM happens.
>
> I hope that you try to test something without CONFIG_COMPACTION.
Hmm a valid point, !CONFIG_COMPACTION should be considered. But reclaim
cannot guarantee forming an order>0 page. But neither does OOM. So would
you suggest we keep reclaiming without OOM as before, to prevent these
regressions? Or where to draw the line here?
> Thanks.
next prev parent reply other threads:[~2016-05-04 8:12 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-20 19:47 [PATCH 0.14] oom detection rework v6 Michal Hocko
2016-04-20 19:47 ` [PATCH 01/14] vmscan: consider classzone_idx in compaction_ready Michal Hocko
2016-04-21 3:32 ` Hillf Danton
2016-05-04 13:56 ` Michal Hocko
2016-04-20 19:47 ` [PATCH 02/14] mm, compaction: change COMPACT_ constants into enum Michal Hocko
2016-04-20 19:47 ` [PATCH 03/14] mm, compaction: cover all compaction mode in compact_zone Michal Hocko
2016-04-20 19:47 ` [PATCH 04/14] mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED Michal Hocko
2016-04-21 7:08 ` Hillf Danton
2016-04-20 19:47 ` [PATCH 05/14] mm, compaction: distinguish between full and partial COMPACT_COMPLETE Michal Hocko
2016-04-21 6:39 ` Hillf Danton
2016-04-20 19:47 ` [PATCH 06/14] mm, compaction: Update compaction_result ordering Michal Hocko
2016-04-21 6:45 ` Hillf Danton
2016-04-20 19:47 ` [PATCH 07/14] mm, compaction: Simplify __alloc_pages_direct_compact feedback interface Michal Hocko
2016-04-21 6:50 ` Hillf Danton
2016-04-20 19:47 ` [PATCH 08/14] mm, compaction: Abstract compaction feedback to helpers Michal Hocko
2016-04-21 6:57 ` Hillf Danton
2016-04-28 8:47 ` Vlastimil Babka
2016-04-20 19:47 ` [PATCH 09/14] mm: use compaction feedback for thp backoff conditions Michal Hocko
2016-04-21 7:05 ` Hillf Danton
2016-04-28 8:53 ` Vlastimil Babka
2016-04-28 12:35 ` Michal Hocko
2016-04-29 9:16 ` Vlastimil Babka
2016-04-29 9:28 ` Michal Hocko
2016-04-20 19:47 ` [PATCH 10/14] mm, oom: rework oom detection Michal Hocko
2016-04-20 19:47 ` [PATCH 11/14] mm: throttle on IO only when there are too many dirty and writeback pages Michal Hocko
2016-04-20 19:47 ` [PATCH 12/14] mm, oom: protect !costly allocations some more Michal Hocko
2016-04-21 8:03 ` Hillf Danton
2016-05-04 6:01 ` Joonsoo Kim
2016-05-04 6:31 ` Joonsoo Kim
2016-05-04 8:56 ` Michal Hocko
2016-05-04 14:57 ` Joonsoo Kim
2016-05-04 18:19 ` Michal Hocko
2016-05-04 8:53 ` Michal Hocko
2016-05-04 14:39 ` Joonsoo Kim
2016-05-04 18:20 ` Michal Hocko
2016-04-20 19:47 ` [PATCH 13/14] mm: consider compaction feedback also for costly allocation Michal Hocko
2016-04-21 8:13 ` Hillf Danton
2016-04-20 19:47 ` [PATCH 14/14] mm, oom, compaction: prevent from should_compact_retry looping for ever for costly orders Michal Hocko
2016-04-21 8:24 ` Hillf Danton
2016-04-28 8:59 ` Vlastimil Babka
2016-04-28 12:39 ` Michal Hocko
2016-05-04 6:27 ` Joonsoo Kim
2016-05-04 9:04 ` Michal Hocko
2016-05-04 15:14 ` Joonsoo Kim
2016-05-04 19:22 ` Michal Hocko
2016-05-04 5:45 ` [PATCH 0.14] oom detection rework v6 Joonsoo Kim
2016-05-04 8:12 ` Vlastimil Babka [this message]
2016-05-04 8:32 ` Joonsoo Kim
2016-05-04 8:50 ` Michal Hocko
2016-05-04 8:47 ` Michal Hocko
2016-05-04 14:32 ` Joonsoo Kim
2016-05-04 18:16 ` Michal Hocko
2016-05-10 6:41 ` Joonsoo Kim
2016-05-10 7:09 ` Vlastimil Babka
2016-05-10 8:00 ` Joonsoo Kim
2016-05-10 9:44 ` Michal Hocko
2016-05-10 9:43 ` Michal Hocko
2016-05-12 2:23 ` Joonsoo Kim
2016-05-12 5:19 ` Joonsoo Kim
2016-05-12 10:59 ` Michal Hocko
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