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authorMel Gorman <mel@csn.ul.ie>2010-05-25 01:32:27 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-25 19:06:59 +0400
commit748446bb6b5a9390b546af38ec899c868a9dbcf0 (patch)
tree4c27d0805a5e094b39ff938ad60dd270b953a79f /include/linux/compaction.h
parentc175a0ce7584e5b498fff8cbdb9aa7912aa9fbba (diff)
downloadlinux-748446bb6b5a9390b546af38ec899c868a9dbcf0.tar.xz
mm: compaction: memory compaction core
This patch is the core of a mechanism which compacts memory in a zone by relocating movable pages towards the end of the zone. A single compaction run involves a migration scanner and a free scanner. Both scanners operate on pageblock-sized areas in the zone. The migration scanner starts at the bottom of the zone and searches for all movable pages within each area, isolating them onto a private list called migratelist. The free scanner starts at the top of the zone and searches for suitable areas and consumes the free pages within making them available for the migration scanner. The pages isolated for migration are then migrated to the newly isolated free pages. [aarcange@redhat.com: Fix unsafe optimisation] [mel@csn.ul.ie: do not schedule work on other CPUs for compaction] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/compaction.h')
-rw-r--r--include/linux/compaction.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
new file mode 100644
index 000000000000..465ca88615ed
--- /dev/null
+++ b/include/linux/compaction.h
@@ -0,0 +1,9 @@
+#ifndef _LINUX_COMPACTION_H
+#define _LINUX_COMPACTION_H
+
+/* Return values for compact_zone() */
+#define COMPACT_CONTINUE 0
+#define COMPACT_PARTIAL 1
+#define COMPACT_COMPLETE 2
+
+#endif /* _LINUX_COMPACTION_H */