vmscan: don't attempt to reclaim anon page in lumpy reclaim when no swap space is...
authorMinchan Kim <minchan.kim@gmail.com>
Tue, 22 Sep 2009 00:01:43 +0000 (17:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 22 Sep 2009 14:17:30 +0000 (07:17 -0700)
The VM already avoids attempting to reclaim anon pages in various places,
But it doesn't avoid it for lumpy reclaim.

It shuffles lru list unnecessary so that it is pointless.

[akpm@linux-foundation.org: cleanup]
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
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>
mm/vmscan.c

index 208071c48bf2fbedba600039a6d19a91c5ce3659..ece2ecb081025dd5f1ebf74ed24c0ce70bd5a4bf 100644 (file)
@@ -935,6 +935,16 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                        /* Check that we have not crossed a zone boundary. */
                        if (unlikely(page_zone_id(cursor_page) != zone_id))
                                continue;
+
+                       /*
+                        * If we don't have enough swap space, reclaiming of
+                        * anon page which don't already have a swap slot is
+                        * pointless.
+                        */
+                       if (nr_swap_pages <= 0 && PageAnon(cursor_page) &&
+                                       !PageSwapCache(cursor_page))
+                               continue;
+
                        if (__isolate_lru_page(cursor_page, mode, file) == 0) {
                                list_move(&cursor_page->lru, dst);
                                mem_cgroup_del_lru(cursor_page);