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authorKemeng Shi <shikemeng@huaweicloud.com>2023-08-04 19:04:48 +0800
committerAndrew Morton <akpm@linux-foundation.org>2023-08-21 13:37:42 -0700
commit7c0a84bd0dc214a710305fbc0f407b8e7c410762 (patch)
tree8b90b4e6f5c20faeabc7bcec3995a8b521eb42b2 /mm/compaction.c
parent530f745c7620af288b71b3d667cb90f10df3defe (diff)
mm/compaction: correct last_migrated_pfn update in compact_zone
We record start pfn of last isolated page block with last_migrated_pfn. And then: 1. We check if we mark the page block skip for exclusive access in isolate_migratepages_block by test if next migrate pfn is still in last isolated page block. If so, we will set finish_pageblock to do the rescan. 2. We check if a full cc->order block is scanned by test if last scan range passes the cc->order block boundary. If so, we flush the pages were freed. We treat cc->migrate_pfn before isolate_migratepages as the start pfn of last isolated page range. However, we always align migrate_pfn to page block or move to another page block in fast_find_migrateblock or in linearly scan forward in isolate_migratepages before do page isolation in isolate_migratepages_block. Update last_migrated_pfn with pageblock_start_pfn(cc->migrate_pfn - 1) after scan to correctly set start pfn of last isolated page range. To avoid that: 1. Miss a rescan with finish_pageblock set as last_migrate_pfn does not point to right pageblock and the migrate will not be in pageblock of last_migrate_pfn as it should be. 2. Wrongly issue flush by test cc->order block boundary with wrong last_migrate_pfn. Link: https://lkml.kernel.org/r/20230804110454.2935878-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/compaction.c')
-rw-r--r--mm/compaction.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index dc16efd5fac5..bc2eda71179a 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2507,7 +2507,8 @@ rescan:
goto check_drain;
case ISOLATE_SUCCESS:
update_cached = false;
- last_migrated_pfn = iteration_start_pfn;
+ last_migrated_pfn = max(cc->zone->zone_start_pfn,
+ pageblock_start_pfn(cc->migrate_pfn - 1));
}
err = migrate_pages(&cc->migratepages, compaction_alloc,