From: Yang Shi <shy828301@gmail.com>
To: mgorman@techsingularity.net
Cc: Linux MM <linux-mm@kvack.org>,
David Rientjes <rientjes@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
torvalds@linux-foundation.org, Michal Hocko <mhocko@kernel.org>,
Huang Ying <ying.huang@intel.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Andrew Morton <akpm@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 06/14] mm, migrate: Immediately fail migration of a page with no migration handler
Date: Thu, 20 Dec 2018 11:44:57 -0800 [thread overview]
Message-ID: <CAHbLzko6jXSikw-4LQXi6KfNR9=U4XJnB_OaaZ4XcNHUj4NLUQ@mail.gmail.com> (raw)
In-Reply-To: <20181214230310.572-7-mgorman@techsingularity.net>
On Fri, Dec 14, 2018 at 3:03 PM Mel Gorman <mgorman@techsingularity.net> wrote:
>
> Pages with no migration handler use a fallback hander which sometimes
> works and sometimes persistently fails such as blockdev pages. Migration
A minor correction. The above statement sounds not accurate anymore
since Jan Kara had patch series (blkdev: avoid migration stalls for
blkdev pages) have blockdev use its own migration handler.
Thanks,
Yang
> will retry a number of times on these persistent pages which is wasteful
> during compaction. This patch will fail migration immediately unless the
> caller is in MIGRATE_SYNC mode which indicates the caller is willing to
> wait while being persistent.
>
> This is not expected to help THP allocation success rates but it does
> reduce latencies slightly.
>
> 1-socket thpfioscale
> 4.20.0-rc6 4.20.0-rc6
> noreserved-v1r4 failfast-v1r4
> Amean fault-both-1 0.00 ( 0.00%) 0.00 * 0.00%*
> Amean fault-both-3 2276.15 ( 0.00%) 3867.54 * -69.92%*
> Amean fault-both-5 4992.20 ( 0.00%) 5313.20 ( -6.43%)
> Amean fault-both-7 7373.30 ( 0.00%) 7039.11 ( 4.53%)
> Amean fault-both-12 11911.52 ( 0.00%) 11328.29 ( 4.90%)
> Amean fault-both-18 17209.42 ( 0.00%) 16455.34 ( 4.38%)
> Amean fault-both-24 20943.71 ( 0.00%) 20448.94 ( 2.36%)
> Amean fault-both-30 22703.00 ( 0.00%) 21655.07 ( 4.62%)
> Amean fault-both-32 22461.41 ( 0.00%) 21415.35 ( 4.66%)
>
> The 2-socket results are not materially different. Scan rates are
> similar as expected.
>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
> ---
> mm/migrate.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index df17a710e2c7..0e27a10429e2 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -885,7 +885,7 @@ static int fallback_migrate_page(struct address_space *mapping,
> */
> if (page_has_private(page) &&
> !try_to_release_page(page, GFP_KERNEL))
> - return -EAGAIN;
> + return mode == MIGRATE_SYNC ? -EAGAIN : -EBUSY;
>
> return migrate_page(mapping, newpage, page, mode);
> }
> --
> 2.16.4
>
next prev parent reply other threads:[~2018-12-20 19:45 UTC|newest]
Thread overview: 33+ 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 [this message]
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
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
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