The quilt patch titled
Subject: mm/compaction: skip page block marked skip in isolate_migratepages_block
has been removed from the -mm tree. Its filename was
mm-compaction-skip-page-block-marked-skip-in-isolate_migratepages_block.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: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Subject: mm/compaction: skip page block marked skip in isolate_migratepages_block
Date: Fri, 4 Aug 2023 19:04:49 +0800
Move migrate_pfn to page block end when block is marked skip to avoid
unnecessary scan retry of that block from upper caller. For example,
compact_zone may wrongly rescan skip page block with finish_pageblock
set as following:
1. cc->migrate point to the start of page block
2. compact_zone record last_migrated_pfn to cc->migrate
3. compact_zone->isolate_migratepages->isolate_migratepages_block
tries to scan the block. The low_pfn maybe moved forward to middle of
block because of free pages at beginning of block.
4. we find first lru page could be isolated but block was exclusive
marked skip.
5. abort isolate_migratepages_block and make cc->migrate_pfn point to
found lru page at middle of block.
6. compact_zone find cc->migrate_pfn and last_migrated_pfn are in the
same block and wrongly rescan the block with finish_pageblock set.
Link: https://lkml.kernel.org/r/20230804110454.2935878-4-shikemeng@xxxxxxxxxxxxxxx
Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/compaction.c | 1 +
1 file changed, 1 insertion(+)
--- a/mm/compaction.c~mm-compaction-skip-page-block-marked-skip-in-isolate_migratepages_block
+++ a/mm/compaction.c
@@ -1140,6 +1140,7 @@ isolate_migratepages_block(struct compac
skip_updated = true;
if (test_and_set_skip(cc, valid_page) &&
!cc->finish_pageblock) {
+ low_pfn = end_pfn;
goto isolate_abort;
}
}
_
Patches currently in -mm which might be from shikemeng@xxxxxxxxxxxxxxx are
