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 and
is currently sitting in the Andrew's git branch mm/mm-hotfixes-unstable.
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.
If this series is accepted and merged after the revert of 7efc3b726103
then a "revert of the revert" will be needed.
[1] http://lore.kernel.org/r/20230113173345.9692-1-vbabka@xxxxxxx
mm/compaction.c | 73 +++++++++++++++++++++++++++++++------------------
mm/internal.h | 6 +++-
2 files changed, 52 insertions(+), 27 deletions(-)
--
2.35.3
Mel Gorman (4):
mm, compaction: Rename compact_control->rescan to finish_pageblock
mm, compaction: Check if a page has been captured before draining PCP
pages
mm, compaction: Finish scanning the current pageblock if requested
mm, compaction: Finish pageblocks on complete migration failure
mm/compaction.c | 73 +++++++++++++++++++++++++++++++------------------
mm/internal.h | 6 +++-
2 files changed, 52 insertions(+), 27 deletions(-)
--
2.35.3
