From: Vlastimil Babka <vbabka@suse.cz>
To: Michal Hocko <mhocko@kernel.org>
Cc: Hugh Dickins <hughd@google.com>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
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>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
Joonsoo Kim <js1304@gmail.com>
Subject: Re: [PATCH] mm, oom: protect !costly allocations some more
Date: Tue, 8 Mar 2016 10:52:15 +0100 [thread overview]
Message-ID: <56DEA0CF.2070902@suse.cz> (raw)
In-Reply-To: <20160308094612.GB13542@dhcp22.suse.cz>
On 03/08/2016 10:46 AM, Michal Hocko wrote:
> On Tue 08-03-16 10:24:56, Vlastimil Babka wrote:
> [...]
>>> @@ -2819,28 +2819,22 @@ static struct page *
>>> __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
>>> int alloc_flags, const struct alloc_context *ac,
>>> enum migrate_mode mode, int *contended_compaction,
>>> - bool *deferred_compaction)
>>> + unsigned long *compact_result)
>>> {
>>> - unsigned long compact_result;
>>> struct page *page;
>>>
>>> - if (!order)
>>> + if (!order) {
>>> + *compact_result = COMPACT_NONE;
>>> return NULL;
>>> + }
>>>
>>> current->flags |= PF_MEMALLOC;
>>> - compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
>>> + *compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
>>> mode, contended_compaction);
>>> current->flags &= ~PF_MEMALLOC;
>>>
>>> - switch (compact_result) {
>>> - case COMPACT_DEFERRED:
>>> - *deferred_compaction = true;
>>> - /* fall-through */
>>> - case COMPACT_SKIPPED:
>>> + if (*compact_result <= COMPACT_SKIPPED)
>>
>> COMPACT_NONE is -1 and compact_result is unsigned long, so this won't
>> work as expected.
>
> Well, COMPACT_NONE is documented as /* compaction disabled */ so we
> should never get it from try_to_compact_pages.
Right.
>
> [...]
>>> @@ -3294,6 +3289,18 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
>>> did_some_progress > 0, no_progress_loops))
>>> goto retry;
>>>
>>> + /*
>>> + * !costly allocations are really important and we have to make sure
>>> + * the compaction wasn't deferred or didn't bail out early due to locks
>>> + * contention before we go OOM.
>>> + */
>>> + if (order && order <= PAGE_ALLOC_COSTLY_ORDER) {
>>> + if (compact_result <= COMPACT_CONTINUE)
>>
>> Same here.
>> I was going to say that this didn't have effect on Sergey's test, but
>> turns out it did :)
>
> This should work as expected because compact_result is unsigned long
> and so this is the unsigned arithmetic. I can make
> #define COMPACT_NONE -1UL
>
> to make the intention more obvious if you prefer, though.
Well, what wasn't obvious to me is actually that here (unlike in the
test above) it was actually intended that COMPACT_NONE doesn't result in
a retry. But it makes sense, otherwise we would retry endlessly if
reclaim couldn't form a higher-order page, right.
> Thanks for the review.
>
next prev parent reply other threads:[~2016-03-08 9:52 UTC|newest]
Thread overview: 150+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-15 18:19 [PATCH 0/3] OOM detection rework v4 Michal Hocko
2015-12-15 18:19 ` [PATCH 1/3] mm, oom: rework oom detection Michal Hocko
2016-01-14 22:58 ` David Rientjes
2016-01-16 1:07 ` Tetsuo Handa
2016-01-19 22:48 ` David Rientjes
2016-01-20 11:13 ` Tetsuo Handa
2016-01-20 13:13 ` Michal Hocko
2016-04-04 8:23 ` Vladimir Davydov
2016-04-04 9:42 ` Michal Hocko
2015-12-15 18:19 ` [PATCH 2/3] mm: throttle on IO only when there are too many dirty and writeback pages Michal Hocko
2016-03-17 11:35 ` Tetsuo Handa
2016-03-17 12:01 ` Michal Hocko
2015-12-15 18:19 ` [PATCH 3/3] mm: use watermak checks for __GFP_REPEAT high order allocations Michal Hocko
2015-12-16 23:35 ` [PATCH 0/3] OOM detection rework v4 Andrew Morton
2015-12-18 12:12 ` Michal Hocko
2015-12-16 23:58 ` Andrew Morton
2015-12-18 13:15 ` Michal Hocko
2015-12-18 16:35 ` Johannes Weiner
2015-12-24 12:41 ` Tetsuo Handa
2015-12-28 12:08 ` Tetsuo Handa
2015-12-28 14:13 ` Tetsuo Handa
2016-01-06 12:44 ` Vlastimil Babka
2016-01-08 12:37 ` Michal Hocko
2015-12-29 16:32 ` Michal Hocko
2015-12-30 15:05 ` Tetsuo Handa
2016-01-02 15:47 ` Tetsuo Handa
2016-01-20 12:24 ` Michal Hocko
2016-01-27 23:18 ` David Rientjes
2016-01-28 21:19 ` Michal Hocko
2015-12-29 16:27 ` Michal Hocko
2016-01-28 20:40 ` [PATCH 4/3] mm, oom: drop the last allocation attempt before out_of_memory Michal Hocko
2016-01-28 21:36 ` Johannes Weiner
2016-01-28 23:19 ` David Rientjes
2016-01-28 23:51 ` Johannes Weiner
2016-01-29 10:39 ` Tetsuo Handa
2016-01-29 15:32 ` Michal Hocko
2016-01-30 12:18 ` Tetsuo Handa
2016-01-29 15:23 ` Michal Hocko
2016-01-29 15:24 ` Michal Hocko
2016-01-28 21:19 ` [PATCH 5/3] mm, vmscan: make zone_reclaimable_pages more precise Michal Hocko
2016-01-28 23:20 ` David Rientjes
2016-01-29 3:41 ` Hillf Danton
2016-01-29 10:35 ` Tetsuo Handa
2016-01-29 15:17 ` Michal Hocko
2016-01-29 21:30 ` Tetsuo Handa
2016-02-03 13:27 ` [PATCH 0/3] OOM detection rework v4 Michal Hocko
2016-02-03 22:58 ` David Rientjes
2016-02-04 12:57 ` Michal Hocko
2016-02-04 13:10 ` Tetsuo Handa
2016-02-04 13:39 ` Michal Hocko
2016-02-04 14:24 ` Michal Hocko
2016-02-07 4:09 ` Tetsuo Handa
2016-02-15 20:06 ` Michal Hocko
2016-02-16 13:10 ` Tetsuo Handa
2016-02-16 15:19 ` Michal Hocko
2016-02-25 3:47 ` Hugh Dickins
2016-02-25 6:48 ` Sergey Senozhatsky
2016-02-25 9:17 ` Hillf Danton
2016-02-25 9:27 ` Michal Hocko
2016-02-25 9:48 ` Hillf Danton
2016-02-25 11:02 ` Sergey Senozhatsky
2016-02-25 9:23 ` Michal Hocko
2016-02-26 6:32 ` Hugh Dickins
2016-02-26 7:54 ` Hillf Danton
2016-02-26 9:24 ` Michal Hocko
2016-02-26 10:27 ` Hillf Danton
2016-02-26 13:49 ` Michal Hocko
2016-02-26 9:33 ` Michal Hocko
2016-02-29 21:02 ` Michal Hocko
2016-03-02 2:19 ` Joonsoo Kim
2016-03-02 9:50 ` Michal Hocko
2016-03-02 13:32 ` Joonsoo Kim
2016-03-02 14:06 ` Michal Hocko
2016-03-02 14:34 ` Joonsoo Kim
2016-03-03 9:26 ` Michal Hocko
2016-03-03 10:29 ` Tetsuo Handa
2016-03-03 14:10 ` Joonsoo Kim
2016-03-03 15:25 ` Michal Hocko
2016-03-04 5:23 ` Joonsoo Kim
2016-03-04 15:15 ` Michal Hocko
2016-03-04 17:39 ` Michal Hocko
2016-03-07 5:23 ` Joonsoo Kim
2016-03-03 15:50 ` Vlastimil Babka
2016-03-03 16:26 ` Michal Hocko
2016-03-04 7:10 ` Joonsoo Kim
2016-03-02 15:01 ` Minchan Kim
2016-03-07 16:08 ` [PATCH] mm, oom: protect !costly allocations some more (was: Re: [PATCH 0/3] OOM detection rework v4) Michal Hocko
2016-03-08 3:51 ` Sergey Senozhatsky
2016-03-08 9:08 ` Michal Hocko
2016-03-08 9:24 ` Sergey Senozhatsky
2016-03-08 9:24 ` [PATCH] mm, oom: protect !costly allocations some more Vlastimil Babka
2016-03-08 9:32 ` Sergey Senozhatsky
2016-03-08 9:46 ` Michal Hocko
2016-03-08 9:52 ` Vlastimil Babka [this message]
2016-03-08 10:10 ` Michal Hocko
2016-03-08 11:12 ` Vlastimil Babka
2016-03-08 12:22 ` Michal Hocko
2016-03-08 12:29 ` Vlastimil Babka
2016-03-08 9:58 ` [PATCH] mm, oom: protect !costly allocations some more (was: Re: [PATCH 0/3] OOM detection rework v4) Sergey Senozhatsky
2016-03-08 13:57 ` Michal Hocko
2016-03-08 10:36 ` Hugh Dickins
2016-03-08 13:42 ` [PATCH 0/2] oom rework: high order enahncements Michal Hocko
2016-03-08 13:42 ` [PATCH 1/3] mm, compaction: change COMPACT_ constants into enum Michal Hocko
2016-03-08 14:19 ` Vlastimil Babka
2016-03-09 3:55 ` Hillf Danton
2016-03-08 13:42 ` [PATCH 2/3] mm, compaction: cover all compaction mode in compact_zone Michal Hocko
2016-03-08 14:22 ` Vlastimil Babka
2016-03-09 3:57 ` Hillf Danton
2016-03-08 13:42 ` [PATCH 3/3] mm, oom: protect !costly allocations some more Michal Hocko
2016-03-08 14:34 ` Vlastimil Babka
2016-03-08 14:48 ` Michal Hocko
2016-03-08 15:03 ` Vlastimil Babka
2016-03-09 11:11 ` Michal Hocko
2016-03-09 14:07 ` Vlastimil Babka
2016-03-11 12:17 ` Hugh Dickins
2016-03-11 13:06 ` Michal Hocko
2016-03-11 19:08 ` Hugh Dickins
2016-03-14 16:21 ` Michal Hocko
2016-03-08 15:19 ` [PATCH] mm, oom: protect !costly allocations some more (was: Re: [PATCH 0/3] OOM detection rework v4) Joonsoo Kim
2016-03-08 16:05 ` Michal Hocko
2016-03-08 17:03 ` Joonsoo Kim
2016-03-09 10:41 ` Michal Hocko
2016-03-11 14:53 ` Joonsoo Kim
2016-03-11 15:20 ` Michal Hocko
2016-02-29 20:35 ` [PATCH 0/3] OOM detection rework v4 Michal Hocko
2016-03-01 7:29 ` Hugh Dickins
2016-03-01 13:38 ` Michal Hocko
2016-03-01 14:40 ` Michal Hocko
2016-03-01 18:14 ` Vlastimil Babka
2016-03-02 2:55 ` Joonsoo Kim
2016-03-02 12:37 ` Michal Hocko
2016-03-02 14:06 ` Joonsoo Kim
[not found] ` <20160302122410.GD26686@dhcp22.suse.cz>
2016-03-02 13:22 ` Vlastimil Babka
2016-03-02 2:28 ` Joonsoo Kim
2016-03-02 12:39 ` Michal Hocko
2016-03-03 9:54 ` Hugh Dickins
2016-03-03 12:32 ` Michal Hocko
2016-03-03 20:57 ` Hugh Dickins
2016-03-04 7:41 ` Vlastimil Babka
2016-03-04 7:53 ` Joonsoo Kim
2016-03-04 12:28 ` Michal Hocko
2016-03-11 10:45 ` Tetsuo Handa
2016-03-11 13:08 ` Michal Hocko
2016-03-11 13:32 ` Tetsuo Handa
2016-03-11 15:28 ` Michal Hocko
2016-03-11 16:49 ` Tetsuo Handa
2016-03-11 17:00 ` Michal Hocko
2016-03-11 17:20 ` Tetsuo Handa
2016-03-12 4:08 ` Tetsuo Handa
2016-03-13 14:41 ` Tetsuo Handa
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