[merged mm-stable] mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch removed from -mm tree

[merged mm-stable] mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/compaction: fix set skip in fast_find_migrateblock
has been removed from the -mm tree.  Its filename was
     mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Chuyi Zhou <zhouchuyi@bytedance.com>
Subject: mm/compaction: fix set skip in fast_find_migrateblock
Date: Wed, 13 Jul 2022 14:20:09 +0800

When we successfully find a pageblock in fast_find_migrateblock(), the
block will be set skip-flag through set_pageblock_skip().  However, when
entering isolate_migratepages_block(), the whole pageblock will be skipped
due to the branch 'if (!valid_page && IS_ALIGNED(low_pfn,
pageblock_nr_pages))'.  Eventually we will goto isolate_abort and isolate
nothing.  That makes fast_find_migrateblock useless.

In this patch, when we find a suitable pageblock in
fast_find_migrateblock, we do noting but let isolate_migratepages_block to
set skip flag to the pageblock after scan it.  Normally, we would isolate
some pages from the fast-find block.

I use mmtest/thpscale-madvhugepage test it. Here is the result:
                            baseline               patch
Amean     fault-both-1      1331.66 (   0.00%)     1261.04 *   5.30%*
Amean     fault-both-3      1383.95 (   0.00%)     1191.69 *  13.89%*
Amean     fault-both-5      1568.13 (   0.00%)     1445.20 *   7.84%*
Amean     fault-both-7      1819.62 (   0.00%)     1555.13 *  14.54%*
Amean     fault-both-12     1106.96 (   0.00%)     1149.43 *  -3.84%*
Amean     fault-both-18     2196.93 (   0.00%)     1875.77 *  14.62%*
Amean     fault-both-24     2642.69 (   0.00%)     2671.21 *  -1.08%*
Amean     fault-both-30     2901.89 (   0.00%)     2857.32 *   1.54%*
Amean     fault-both-32     3747.00 (   0.00%)     3479.23 *   7.15%*

Link: https://lkml.kernel.org/r/20220713062009.597255-1-zhouchuyi@bytedance.com
Fixes: 70b44595eafe9 ("mm, compaction: use free lists to quickly locate a migration source")
Signed-off-by: zhouchuyi <zhouchuyi@bytedance.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/compaction.c |    1 -
 1 file changed, 1 deletion(-)

--- a/mm/compaction.c~mm-compaction-fix-set-skip-in-fast_find_migrateblock
+++ a/mm/compaction.c
@@ -1851,7 +1851,6 @@ static unsigned long fast_find_migratebl
 					pfn = cc->zone->zone_start_pfn;
 				cc->fast_search_fail = 0;
 				found_block = true;
-				set_pageblock_skip(freepage);
 				break;
 			}
 		}
_

Patches currently in -mm which might be from zhouchuyi@bytedance.com are