From: Mel Gorman <mgorman@techsingularity.net>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Linux-MM <linux-mm@kvack.org>,
David Rientjes <rientjes@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Vlastimil Babka <vbabka@suse.cz>,
ying.huang@intel.com, kirill@shutemov.name,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 00/25] Increase success rates and reduce latency of compaction v2
Date: Tue, 8 Jan 2019 09:12:17 +0000 [thread overview]
Message-ID: <20190108091217.GL31517@techsingularity.net> (raw)
In-Reply-To: <20190107154354.b0805ca15767fc7ea9e37545@linux-foundation.org>
On Mon, Jan 07, 2019 at 03:43:54PM -0800, Andrew Morton wrote:
> On Fri, 4 Jan 2019 12:49:46 +0000 Mel Gorman <mgorman@techsingularity.net> wrote:
>
> > This series reduces scan rates and success rates of compaction, primarily
> > by using the free lists to shorten scans, better controlling of skip
> > information and whether multiple scanners can target the same block and
> > capturing pageblocks before being stolen by parallel requests. The series
> > is based on the 4.21/5.0 merge window after Andrew's tree had been merged.
> > It's known to rebase cleanly.
> >
> > ...
> >
> > include/linux/compaction.h | 3 +-
> > include/linux/gfp.h | 7 +-
> > include/linux/mmzone.h | 2 +
> > include/linux/sched.h | 4 +
> > kernel/sched/core.c | 3 +
> > mm/compaction.c | 1031 ++++++++++++++++++++++++++++++++++----------
> > mm/internal.h | 23 +-
> > mm/migrate.c | 2 +-
> > mm/page_alloc.c | 70 ++-
> > 9 files changed, 908 insertions(+), 237 deletions(-)
>
> Boy that's a lot of material.
It's unfortunate I know. It just turned out that there is a lot that had
to change to make the most important patches in the series work without
obvious side-effects.
> I just tossed it in there unread for
> now. Do you have any suggestions as to how we can move ahead with
> getting this appropriately reviewed and tested?
>
The main workloads that should see a difference are those that use
MADV_HUGEPAGE or change /sys/kernel/mm/transparent_hugepage/defrag. I'm
expecting MADV_HUGEPAGE is more common in practice. By default, there
should be little change as direct compaction is not used heavily for THP.
Although SLUB workloads might see a difference given a long enough uptime,
it will be relatively difficult to detect.
As this was partially motivated by the __GFP_THISNODE discussion, I
would like to hear from David if this series makes an impact, if any,
when starting Google workloads on a fragmented system.
Similarly, I would be interested in hearing if Andrea's KVM startup times
see any benefit. I'm expecting less here as I expect that workload is
still bound by reclaim thrashing the local node in reclaim. Still, a
confirmation would be nice and if there is any benefit then it's a plus
even if the workload gets reclaimed excessively.
Local tests didn't show up anything interesting *other* than what is
already in the changelogs as those workloads are specifically targetting
those paths. Intel LKP has not reported any regressions (functional or
performance) despite being on git.kernel.org for a few weeks. However,
as they are using default configurations, this is not much of a surprise.
Review is harder. Vlastimil would normally be the best fit as he has
worked on compaction but for him or for anyone else, I'm expecting they're
dealing with a backlog after the holidays. I know I still have to get
to Vlastimil's recent series on THP allocations so I'm guilty of the same
crime with respect to review.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2019-01-08 9:12 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-04 12:49 [PATCH 00/25] Increase success rates and reduce latency of compaction v2 Mel Gorman
2019-01-04 12:49 ` [PATCH 01/25] mm, compaction: Shrink compact_control Mel Gorman
2019-01-04 12:49 ` [PATCH 02/25] mm, compaction: Rearrange compact_control Mel Gorman
2019-01-04 12:49 ` [PATCH 03/25] mm, compaction: Remove last_migrated_pfn from compact_control Mel Gorman
2019-01-04 12:49 ` [PATCH 04/25] mm, compaction: Remove unnecessary zone parameter in some instances Mel Gorman
2019-01-15 11:43 ` Vlastimil Babka
2019-01-04 12:49 ` [PATCH 05/25] mm, compaction: Rename map_pages to split_map_pages Mel Gorman
2019-01-15 11:59 ` Vlastimil Babka
2019-01-04 12:49 ` [PATCH 06/25] mm, compaction: Skip pageblocks with reserved pages Mel Gorman
2019-01-15 12:10 ` Vlastimil Babka
2019-01-15 12:50 ` Mel Gorman
2019-01-16 9:42 ` Mel Gorman
2019-01-04 12:49 ` [PATCH 07/25] mm, migrate: Immediately fail migration of a page with no migration handler Mel Gorman
2019-01-04 12:49 ` [PATCH 08/25] mm, compaction: Always finish scanning of a full pageblock Mel Gorman
2019-01-04 12:49 ` [PATCH 09/25] mm, compaction: Use the page allocator bulk-free helper for lists of pages Mel Gorman
2019-01-15 12:39 ` Vlastimil Babka
2019-01-16 9:46 ` Mel Gorman
2019-01-04 12:49 ` [PATCH 10/25] mm, compaction: Ignore the fragmentation avoidance boost for isolation and compaction Mel Gorman
2019-01-15 13:18 ` Vlastimil Babka
2019-01-04 12:49 ` [PATCH 11/25] mm, compaction: Use free lists to quickly locate a migration source Mel Gorman
2019-01-16 13:15 ` Vlastimil Babka
2019-01-16 14:33 ` Mel Gorman
2019-01-16 15:00 ` Vlastimil Babka
2019-01-16 15:43 ` Mel Gorman
2019-01-04 12:49 ` [PATCH 12/25] mm, compaction: Keep migration source private to a single compaction instance Mel Gorman
2019-01-16 15:45 ` Vlastimil Babka
2019-01-16 16:15 ` Mel Gorman
2019-01-17 9:29 ` Vlastimil Babka
2019-01-17 9:40 ` Vlastimil Babka
2019-01-04 12:49 ` [PATCH 13/25] mm, compaction: Use free lists to quickly locate a migration target Mel Gorman
2019-01-17 14:36 ` Vlastimil Babka
2019-01-17 15:51 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 14/25] mm, compaction: Avoid rescanning the same pageblock multiple times Mel Gorman
2019-01-17 15:16 ` Vlastimil Babka
2019-01-17 16:00 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 15/25] mm, compaction: Finish pageblock scanning on contention Mel Gorman
2019-01-17 16:38 ` Vlastimil Babka
2019-01-17 17:11 ` Mel Gorman
2019-01-18 8:57 ` Vlastimil Babka
2019-01-04 12:50 ` [PATCH 16/25] mm, compaction: Check early for huge pages encountered by the migration scanner Mel Gorman
2019-01-17 17:01 ` Vlastimil Babka
2019-01-17 17:35 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 17/25] mm, compaction: Keep cached migration PFNs synced for unusable pageblocks Mel Gorman
2019-01-17 17:17 ` Vlastimil Babka
2019-01-17 17:37 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 18/25] mm, compaction: Rework compact_should_abort as compact_check_resched Mel Gorman
2019-01-17 17:27 ` Vlastimil Babka
2019-01-04 12:50 ` [PATCH 19/25] mm, compaction: Do not consider a need to reschedule as contention Mel Gorman
2019-01-17 17:33 ` Vlastimil Babka
2019-01-17 18:05 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 20/25] mm, compaction: Reduce unnecessary skipping of migration target scanner Mel Gorman
2019-01-17 17:58 ` Vlastimil Babka
2019-01-17 19:39 ` Mel Gorman
2019-01-18 9:09 ` Vlastimil Babka
2019-01-04 12:50 ` [PATCH 21/25] mm, compaction: Round-robin the order while searching the free lists for a target Mel Gorman
2019-01-18 9:17 ` Vlastimil Babka
2019-01-04 12:50 ` [PATCH 22/25] mm, compaction: Sample pageblocks for free pages Mel Gorman
2019-01-18 10:38 ` Vlastimil Babka
2019-01-18 13:44 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 23/25] mm, compaction: Be selective about what pageblocks to clear skip hints Mel Gorman
2019-01-18 12:55 ` Vlastimil Babka
2019-01-18 14:10 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 24/25] mm, compaction: Capture a page under direct compaction Mel Gorman
2019-01-18 13:40 ` Vlastimil Babka
2019-01-18 14:39 ` Mel Gorman
2019-01-04 12:50 ` [PATCH 25/25] mm, compaction: Do not direct compact remote memory Mel Gorman
2019-01-18 13:51 ` Vlastimil Babka
2019-01-18 14:46 ` Mel Gorman
2019-01-07 23:43 ` [PATCH 00/25] Increase success rates and reduce latency of compaction v2 Andrew Morton
2019-01-08 9:12 ` Mel Gorman [this message]
2019-01-09 11:13 ` [PATCH] mm, compaction: Use free lists to quickly locate a migration target -fix Mel Gorman
2019-01-09 19:27 ` Andrew Morton
2019-01-09 21:26 ` Mel Gorman
2019-01-09 11:15 ` [PATCH] mm, compaction: Finish pageblock scanning on contention -fix Mel Gorman
2019-01-09 11:16 ` [PATCH] mm, compaction: Round-robin the order while searching the free lists for a target -fix Mel Gorman
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