From: Vlastimil Babka <vbabka@suse.cz>
To: Mel Gorman <mgorman@techsingularity.net>, Linux-MM <linux-mm@kvack.org>
Cc: David Rientjes <rientjes@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Michal Hocko <mhocko@kernel.org>,
ying.huang@intel.com, kirill@shutemov.name,
Andrew Morton <akpm@linux-foundation.org>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 09/14] mm, compaction: Ignore the fragmentation avoidance boost for isolation and compaction
Date: Tue, 18 Dec 2018 13:36:42 +0100 [thread overview]
Message-ID: <f8aeec16-65de-b873-3362-3c7cb30c4ac6@suse.cz> (raw)
In-Reply-To: <20181214230310.572-10-mgorman@techsingularity.net>
On 12/15/18 12:03 AM, Mel Gorman wrote:
> When pageblocks get fragmented, watermarks are artifically boosted to pages
> are reclaimed to avoid further fragmentation events. However, compaction
> is often either fragmentation-neutral or moving movable pages away from
> unmovable/reclaimable pages. As the actual watermarks are preserved,
> allow compaction to ignore the boost factor.
Right, I should have realized that when reviewing the boost patch. I
think it would be useful to do the same change in
__compaction_suitable() as well. Compaction has its own "gap".
> 1-socket thpscale
> 4.20.0-rc6 4.20.0-rc6
> finishscan-v1r4 noboost-v1r4
> Amean fault-both-1 0.00 ( 0.00%) 0.00 * 0.00%*
> Amean fault-both-3 3849.90 ( 0.00%) 3753.53 ( 2.50%)
> Amean fault-both-5 5054.13 ( 0.00%) 5396.32 ( -6.77%)
> Amean fault-both-7 7061.77 ( 0.00%) 7393.46 ( -4.70%)
> Amean fault-both-12 11560.59 ( 0.00%) 12155.50 ( -5.15%)
> Amean fault-both-18 16120.15 ( 0.00%) 16445.96 ( -2.02%)
> Amean fault-both-24 19804.31 ( 0.00%) 20465.03 ( -3.34%)
> Amean fault-both-30 25018.73 ( 0.00%) 20813.54 * 16.81%*
> Amean fault-both-32 24380.19 ( 0.00%) 22384.02 ( 8.19%)
>
> The impact on the scan rates is a mixed bag because this patch is very
> sensitive to timing and whether the boost was active or not. However,
> detailed tracing indicated that failure of migration due to a premature
> ENOMEM triggered by watermark checks were eliminated.
>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
> ---
> mm/page_alloc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 80535cd55a92..c7b80e62bfd9 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -3043,7 +3043,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
> * watermark, because we already know our high-order page
> * exists.
> */
> - watermark = min_wmark_pages(zone) + (1UL << order);
> + watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
> if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
> return 0;
>
>
next prev parent reply other threads:[~2018-12-18 12:36 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-14 23:02 [RFC PATCH 00/14] Increase success rates and reduce latency of compaction v1 Mel Gorman
2018-12-14 23:02 ` [PATCH 01/14] mm, compaction: Shrink compact_control Mel Gorman
2018-12-17 12:27 ` Vlastimil Babka
2018-12-14 23:02 ` [PATCH 02/14] mm, compaction: Rearrange compact_control Mel Gorman
2018-12-17 13:20 ` Vlastimil Babka
2018-12-14 23:02 ` [PATCH 03/14] mm, compaction: Remove last_migrated_pfn from compact_control Mel Gorman
2018-12-17 13:50 ` Vlastimil Babka
2018-12-14 23:03 ` [PATCH 04/14] mm, compaction: Rename map_pages to split_map_pages Mel Gorman
2018-12-17 14:06 ` Vlastimil Babka
2018-12-17 14:30 ` Mel Gorman
2018-12-14 23:03 ` [PATCH 05/14] mm, compaction: Skip pageblocks with reserved pages Mel Gorman
2018-12-18 8:08 ` Vlastimil Babka
2018-12-18 8:38 ` Mel Gorman
2018-12-14 23:03 ` [PATCH 06/14] mm, migrate: Immediately fail migration of a page with no migration handler Mel Gorman
2018-12-18 9:06 ` Vlastimil Babka
2018-12-18 9:55 ` Mel Gorman
2018-12-20 19:44 ` Yang Shi
2018-12-20 19:44 ` Yang Shi
2018-12-20 20:31 ` Mel Gorman
2018-12-14 23:03 ` [PATCH 07/14] mm, compaction: Always finish scanning of a full pageblock Mel Gorman
2018-12-18 9:23 ` Vlastimil Babka
2018-12-14 23:03 ` [PATCH 08/14] mm, compaction: Use the page allocator bulk-free helper for lists of pages Mel Gorman
2018-12-18 9:55 ` Vlastimil Babka
2018-12-19 16:04 ` Mel Gorman
2018-12-14 23:03 ` [PATCH 09/14] mm, compaction: Ignore the fragmentation avoidance boost for isolation and compaction Mel Gorman
2018-12-18 12:36 ` Vlastimil Babka [this message]
2018-12-18 13:51 ` Mel Gorman
2018-12-18 13:58 ` Vlastimil Babka
2018-12-18 14:29 ` Mel Gorman
2018-12-14 23:04 ` [PATCH 10/14] mm, compaction: Use free lists to quickly locate a migration source Mel Gorman
2018-12-14 23:05 ` [PATCH 11/14] mm, compaction: Keep migration source private to a single compaction instance Mel Gorman
2018-12-14 23:05 ` [PATCH 12/14] mm, compaction: Use free lists to quickly locate a migration target Mel Gorman
2018-12-14 23:05 ` [PATCH 13/14] mm, compaction: Capture a page under direct compaction Mel Gorman
2018-12-14 23:06 ` [PATCH 14/14] mm, compaction: Do not direct compact remote memory Mel Gorman
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=f8aeec16-65de-b873-3362-3c7cb30c4ac6@suse.cz \
--to=vbabka@suse.cz \
--cc=aarcange@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=kirill@shutemov.name \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@techsingularity.net \
--cc=mhocko@kernel.org \
--cc=rientjes@google.com \
--cc=torvalds@linux-foundation.org \
--cc=ying.huang@intel.com \
/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