diff options
| author | Mel Gorman <mgorman@suse.de> | 2012-10-08 16:32:45 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-09 16:22:50 +0900 |
| commit | c89511ab2f8fe2b47585e60da8af7fd213ec877e (patch) | |
| tree | c6b04cb5335957e8409edc77ca23ef012d9d326d /mm/internal.h | |
| parent | bb13ffeb9f6bfeb301443994dfbf29f91117dfb3 (diff) | |
mm: compaction: Restart compaction from near where it left off
This is almost entirely based on Rik's previous patches and discussions
with him about how this might be implemented.
Order > 0 compaction stops when enough free pages of the correct page
order have been coalesced. When doing subsequent higher order
allocations, it is possible for compaction to be invoked many times.
However, the compaction code always starts out looking for things to
compact at the start of the zone, and for free pages to compact things to
at the end of the zone.
This can cause quadratic behaviour, with isolate_freepages starting at the
end of the zone each time, even though previous invocations of the
compaction code already filled up all free memory on that end of the zone.
This can cause isolate_freepages to take enormous amounts of CPU with
certain workloads on larger memory systems.
This patch caches where the migration and free scanner should start from
on subsequent compaction invocations using the pageblock-skip information.
When compaction starts it begins from the cached restart points and will
update the cached restart points until a page is isolated or a pageblock
is skipped that would have been scanned by synchronous compaction.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Richard Davies <richard@arachsys.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Avi Kivity <avi@redhat.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/internal.h')
| -rw-r--r-- | mm/internal.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/internal.h b/mm/internal.h index 7ba56ac360b..7f72f249bc2 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -121,6 +121,10 @@ struct compact_control { unsigned long migrate_pfn; /* isolate_migratepages search base */ bool sync; /* Synchronous migration */ bool ignore_skip_hint; /* Scan blocks even if marked skip */ + bool finished_update_free; /* True when the zone cached pfns are + * no longer being updated + */ + bool finished_update_migrate; int order; /* order a direct compactor needs */ int migratetype; /* MOVABLE, RECLAIMABLE etc */ |