path: root/mm/compaction.c
diff options
authorRafael Aquini <aquini@redhat.com>2012-12-11 16:02:42 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 17:22:27 -0800
commitbf6bddf1924eaebf2beb85e4249a89dd16d4eed6 (patch)
treee03b66a6779727a44f40c4e8f43a06c52d39a6ef /mm/compaction.c
parent18468d93e53b037e1a04ec58398eab763d054064 (diff)
mm: introduce compaction and migration for ballooned pages
Memory fragmentation introduced by ballooning might reduce significantly the number of 2MB contiguous memory blocks that can be used within a guest, thus imposing performance penalties associated with the reduced number of transparent huge pages that could be used by the guest workload. This patch introduces the helper functions as well as the necessary changes to teach compaction and migration bits how to cope with pages which are part of a guest memory balloon, in order to make them movable by memory compaction procedures. Signed-off-by: Rafael Aquini <aquini@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/compaction.c')
1 files changed, 19 insertions, 2 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index 694eaabaaeb..470474c03b6 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -14,6 +14,7 @@
#include <linux/backing-dev.h>
#include <linux/sysctl.h>
#include <linux/sysfs.h>
+#include <linux/balloon_compaction.h>
#include "internal.h"
#if defined CONFIG_COMPACTION || defined CONFIG_CMA
@@ -565,9 +566,24 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
goto next_pageblock;
- /* Check may be lockless but that's ok as we recheck later */
- if (!PageLRU(page))
+ /*
+ * Check may be lockless but that's ok as we recheck later.
+ * It's possible to migrate LRU pages and balloon pages
+ * Skip any other type of page
+ */
+ if (!PageLRU(page)) {
+ if (unlikely(balloon_page_movable(page))) {
+ if (locked && balloon_page_isolate(page)) {
+ /* Successfully isolated */
+ cc->finished_update_migrate = true;
+ list_add(&page->lru, migratelist);
+ cc->nr_migratepages++;
+ nr_isolated++;
+ goto check_compact_cluster;
+ }
+ }
+ }
* PageLRU is set. lru_lock normally excludes isolation
@@ -621,6 +637,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc,
/* Avoid isolating too much */
if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) {