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| author | Mel Gorman <mgorman@techsingularity.net> | 2023-01-25 13:44:31 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-02 22:33:29 -0800 |
| commit | 48731c8436c68ce5597dfe72f3836bd6808bedde (patch) | |
| tree | 39f56a1a8f141dc39cec022f745427d1df0b2c49 /mm/internal.h | |
| parent | c5acf1f6f0a11b8e521ad43f59b1bed27dcf34f6 (diff) | |
| download | linux-48731c8436c68ce5597dfe72f3836bd6808bedde.tar.gz linux-48731c8436c68ce5597dfe72f3836bd6808bedde.tar.bz2 linux-48731c8436c68ce5597dfe72f3836bd6808bedde.zip | |
mm, compaction: rename compact_control->rescan to finish_pageblock
Patch series "Fix excessive CPU usage during compaction".
Commit 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
fixed a problem where pageblocks found by fast_find_migrateblock() were
ignored. Unfortunately there were numerous bug reports complaining about high
CPU usage and massive stalls once 6.1 was released. Due to the severity,
the patch was reverted by Vlastimil as a short-term fix[1] to -stable.
The underlying problem for each of the bugs is suspected to be the
repeated scanning of the same pageblocks. This series should guarantee
forward progress even with commit 7efc3b726103. More information is in
the changelog for patch 4.
[1] http://lore.kernel.org/r/20230113173345.9692-1-vbabka@suse.cz
This patch (of 4):
The rescan field was not well named albeit accurate at the time. Rename
the field to finish_pageblock to indicate that the remainder of the
pageblock should be scanned regardless of COMPACT_CLUSTER_MAX. The intent
is that pageblocks with transient failures get marked for skipping to
avoid revisiting the same pageblock.
Link: https://lkml.kernel.org/r/20230125134434.18017-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Chuyi Zhou <zhouchuyi@bytedance.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/internal.h')
| -rw-r--r-- | mm/internal.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/internal.h b/mm/internal.h index ce462bf145b4..2d1b9fa8083e 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -448,7 +448,11 @@ struct compact_control { bool proactive_compaction; /* kcompactd proactive compaction */ bool whole_zone; /* Whole zone should/has been scanned */ bool contended; /* Signal lock contention */ - bool rescan; /* Rescanning the same pageblock */ + bool finish_pageblock; /* Scan the remainder of a pageblock. Used + * when there are potentially transient + * isolation or migration failures to + * ensure forward progress. + */ bool alloc_contig; /* alloc_contig_range allocation */ }; |