linux.git/mm/compaction.c, branch v6.6

merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes

2023-08-21T21:26:20+00:00

mm/compaction: remove unused parameter pgdata of fragmentation_score_wmark

2023-08-21T20:37:50+00:00

Parameter pgdat is not used in fragmentation_score_wmark. Just remove it.

Link: https://lkml.kernel.org/r/20230809094910.3092446-1-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi 
Reviewed-by: David Hildenbrand 
Acked-by: Mel Gorman 
Reviewed-by: Baolin Wang 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton

mm/compaction: only set skip flag if cc->no_set_skip_hint is false

2023-08-21T20:37:43+00:00

Keep the same logic as update_pageblock_skip, only set skip if
no_set_skip_hint is false which is more reasonable.

Link: https://lkml.kernel.org/r/20230804110454.2935878-9-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi 
Reviewed-by: David Hildenbrand 
Cc: Baolin Wang 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton

mm/compaction: remove unnecessary return for void function

2023-08-21T20:37:43+00:00

Remove unnecessary return for void function

Link: https://lkml.kernel.org/r/20230804110454.2935878-8-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi 
Reviewed-by: David Hildenbrand 
Reviewed-by: Baolin Wang 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton

mm/compaction: correct comment to complete migration failure

2023-08-21T20:37:43+00:00

Commit cfccd2e63e7e0 ("mm, compaction: finish pageblocks on complete
migration failure") convert cc->order aligned check to page block order
aligned check.  Correct comment relevant with it.

Link: https://lkml.kernel.org/r/20230804110454.2935878-7-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi 
Cc: Baolin Wang 
Cc: David Hildenbrand 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton

mm/compaction: correct comment of cached migrate pfn update

2023-08-21T20:37:42+00:00

Commit e380bebe47715 ("mm, compaction: keep migration source private to a
single compaction instance") moved update of async and sync
compact_cached_migrate_pfn from update_pageblock_skip to
update_cached_migrate but left the comment behind.  Move the relevant
comment to correct this.

Link: https://lkml.kernel.org/r/20230804110454.2935878-6-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi 
Reviewed-by: David Hildenbrand 
Reviewed-by: Baolin Wang 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton

mm/compaction: correct comment of fast_find_migrateblock in isolate_migratepages

2023-08-21T20:37:42+00:00

After 90ed667c03fe5 ("Revert "Revert "mm/compaction: fix set skip in
fast_find_migrateblock"""), we remove skip set in fast_find_migrateblock. 
Correct comment that fast_find_block is used to avoid isolation_suitable
check for pageblock returned from fast_find_migrateblock because
fast_find_migrateblock will mark found pageblock skipped.

Instead, comment that fast_find_block is used to avoid a redundant check
of fast found pageblock which is already checked skip flag inside
fast_find_migrateblock.

Link: https://lkml.kernel.org/r/20230804110454.2935878-5-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi 
Reviewed-by: Baolin Wang 
Cc: David Hildenbrand 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton

mm/compaction: skip page block marked skip in isolate_migratepages_block

2023-08-21T20:37:42+00:00

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@huaweicloud.com
Signed-off-by: Kemeng Shi 
Reviewed-by: Baolin Wang 
Cc: David Hildenbrand 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton

mm/compaction: correct last_migrated_pfn update in compact_zone

2023-08-21T20:37:42+00:00

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 
Reviewed-by: Baolin Wang 
Cc: David Hildenbrand 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton

mm/compaction: remove unnecessary "else continue" at end of loop in isolate_freepages_block

2023-08-21T20:37:39+00:00

There is no behavior change to remove "else continue" code at end of scan
loop.  Just remove it to make code cleaner.

Link: https://lkml.kernel.org/r/20230803094901.2915942-5-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi 
Reviewed-by: Baolin Wang 
Cc: David Hildenbrand 
Cc: Kemeng Shi 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton