From: Andrew Morton <akpm@linux-foundation.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: 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>,
Joonsoo Kim <js1304@gmail.com>,
Hillf Danton <hillf.zj@alibaba-inc.com>, <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>, Hugh Dickins <hughd@google.com>
Subject: Re: [PATCH 09/11] mm, compaction: Abstract compaction feedback to helpers
Date: Tue, 5 Apr 2016 16:58:26 -0700 [thread overview]
Message-ID: <20160405165826.012236e79db7f396fda546a8@linux-foundation.org> (raw)
In-Reply-To: <1459855533-4600-10-git-send-email-mhocko@kernel.org>
On Tue, 5 Apr 2016 13:25:31 +0200 Michal Hocko <mhocko@kernel.org> wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> Compaction can provide a wild variation of feedback to the caller. Many
> of them are implementation specific and the caller of the compaction
> (especially the page allocator) shouldn't be bound to specifics of the
> current implementation.
>
> This patch abstracts the feedback into three basic types:
> - compaction_made_progress - compaction was active and made some
> progress.
> - compaction_failed - compaction failed and further attempts to
> invoke it would most probably fail and therefore it is not
> worth retrying
> - compaction_withdrawn - compaction wasn't invoked for an
> implementation specific reasons. In the current implementation
> it means that the compaction was deferred, contended or the
> page scanners met too early without any progress. Retrying is
> still worthwhile.
>
> ...
>
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3362,25 +3362,12 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
> if (page)
> goto got_pg;
>
> - /* Checks for THP-specific high-order allocations */
> - if (is_thp_gfp_mask(gfp_mask)) {
> - /*
> - * If compaction is deferred for high-order allocations, it is
> - * because sync compaction recently failed. If this is the case
> - * and the caller requested a THP allocation, we do not want
> - * to heavily disrupt the system, so we fail the allocation
> - * instead of entering direct reclaim.
> - */
> - if (compact_result == COMPACT_DEFERRED)
> - goto nopage;
> -
> - /*
> - * Compaction is contended so rather back off than cause
> - * excessive stalls.
> - */
> - if(compact_result == COMPACT_CONTENDED)
> - goto nopage;
> - }
> + /*
> + * Checks for THP-specific high-order allocations and back off
> + * if the the compaction backed off
> + */
> + if (is_thp_gfp_mask(gfp_mask) && compaction_withdrawn(compact_result))
> + goto nopage;
This change smashed into Hugh's "huge tmpfs: shmem_huge_gfpmask and
shmem_recovery_gfpmask".
I ended up doing this:
/* Checks for THP-specific high-order allocations */
if (!is_thp_allocation(gfp_mask, order))
migration_mode = MIGRATE_SYNC_LIGHT;
/*
* Checks for THP-specific high-order allocations and back off
* if the the compaction backed off
*/
if (is_thp_allocation(gfp_mask) && compaction_withdrawn(compact_result))
goto nopage;
next prev parent reply other threads:[~2016-04-05 23:58 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-05 11:25 [PATCH 00/11] oom detection rework v5 Michal Hocko
2016-04-05 11:25 ` [PATCH 01/11] mm, oom: rework oom detection Michal Hocko
2016-04-05 11:25 ` [PATCH 02/11] mm: throttle on IO only when there are too many dirty and writeback pages Michal Hocko
2016-04-05 11:25 ` [PATCH 03/11] mm, compaction: change COMPACT_ constants into enum Michal Hocko
2016-04-05 11:25 ` [PATCH 04/11] mm, compaction: cover all compaction mode in compact_zone Michal Hocko
2016-04-05 11:25 ` [PATCH 05/11] mm, compaction: distinguish COMPACT_DEFERRED from COMPACT_SKIPPED Michal Hocko
2016-04-11 11:02 ` Vlastimil Babka
2016-04-11 11:24 ` Michal Hocko
2016-04-05 11:25 ` [PATCH 06/11] mm, compaction: distinguish between full and partial COMPACT_COMPLETE Michal Hocko
2016-04-11 12:10 ` Vlastimil Babka
2016-04-11 12:46 ` Michal Hocko
2016-04-11 12:53 ` Vlastimil Babka
2016-04-11 13:27 ` Michal Hocko
2016-04-11 13:42 ` Vlastimil Babka
2016-04-11 13:46 ` Michal Hocko
2016-04-05 11:25 ` [PATCH 07/11] mm, compaction: Update compaction_result ordering Michal Hocko
2016-04-11 12:16 ` Vlastimil Babka
2016-04-05 11:25 ` [PATCH 08/11] mm, compaction: Simplify __alloc_pages_direct_compact feedback interface Michal Hocko
2016-04-11 13:48 ` Vlastimil Babka
2016-04-05 11:25 ` [PATCH 09/11] mm, compaction: Abstract compaction feedback to helpers Michal Hocko
2016-04-05 23:58 ` Andrew Morton [this message]
2016-04-06 0:55 ` Hugh Dickins
2016-04-06 9:26 ` Michal Hocko
2016-04-06 17:46 ` Andrew Morton
2016-04-11 14:39 ` Vlastimil Babka
2016-04-11 15:14 ` Michal Hocko
2016-04-11 15:33 ` Michal Hocko
2016-04-12 11:53 ` Vlastimil Babka
2016-04-12 12:23 ` Michal Hocko
2016-04-11 15:40 ` Michal Hocko
2016-04-11 16:07 ` [RFC PATCH] mm: use compaction feedback for thp backoff conditions Michal Hocko
2016-04-12 11:54 ` [PATCH 09/11] mm, compaction: Abstract compaction feedback to helpers Vlastimil Babka
2016-04-05 11:25 ` [PATCH 10/11] mm, oom: protect !costly allocations some more Michal Hocko
2016-04-06 0:06 ` Andrew Morton
2016-04-06 9:28 ` Michal Hocko
2016-04-11 14:48 ` Vlastimil Babka
2016-04-05 11:25 ` [PATCH 11/11] mm: consider compaction feedback also for costly allocation Michal Hocko
2016-04-05 12:46 ` Michal Hocko
2016-04-11 15:07 ` Vlastimil Babka
2016-04-05 12:47 ` [PATCH 00/11] oom detection rework v5 Michal Hocko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160405165826.012236e79db7f396fda546a8@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=hannes@cmpxchg.org \
--cc=hillf.zj@alibaba-inc.com \
--cc=hughd@google.com \
--cc=js1304@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=mhocko@kernel.org \
--cc=mhocko@suse.com \
--cc=penguin-kernel@I-love.SAKURA.ne.jp \
--cc=rientjes@google.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).