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authorDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>2009-06-16 15:33:15 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-16 19:47:45 -0700
commit9198e96c06744517e3b18fce8be6db61e96a3227 (patch)
tree3d79e58771cc27204980a0350abafaf6e7524447 /mm
parent3eb4140f0389bdada022d5e8efd88504ad30df14 (diff)
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vmscan: handle may_swap more strictly
Commit 2e2e425989080cc534fc0fca154cae515f971cf5 ("vmscan,memcg: reintroduce sc->may_swap) add may_swap flag and handle it at get_scan_ratio(). But the result of get_scan_ratio() is ignored when priority == 0, so anon lru is scanned even if may_swap == 0 or nr_swap_pages == 0. IMHO, this is not an expected behavior. As for memcg especially, because of this behavior many and many pages are swapped-out just in vain when oom is invoked by mem+swap limit. This patch is for handling may_swap flag more strictly. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/vmscan.c18
1 files changed, 9 insertions, 9 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index f3a55d1f9ab7..057e44b97aa1 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1430,13 +1430,6 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
unsigned long ap, fp;
struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
- /* If we have no swap space, do not bother scanning anon pages. */
- if (!sc->may_swap || (nr_swap_pages <= 0)) {
- percent[0] = 0;
- percent[1] = 100;
- return;
- }
-
anon = zone_nr_pages(zone, sc, LRU_ACTIVE_ANON) +
zone_nr_pages(zone, sc, LRU_INACTIVE_ANON);
file = zone_nr_pages(zone, sc, LRU_ACTIVE_FILE) +
@@ -1534,15 +1527,22 @@ static void shrink_zone(int priority, struct zone *zone,
enum lru_list l;
unsigned long nr_reclaimed = sc->nr_reclaimed;
unsigned long swap_cluster_max = sc->swap_cluster_max;
+ int noswap = 0;
- get_scan_ratio(zone, sc, percent);
+ /* If we have no swap space, do not bother scanning anon pages. */
+ if (!sc->may_swap || (nr_swap_pages <= 0)) {
+ noswap = 1;
+ percent[0] = 0;
+ percent[1] = 100;
+ } else
+ get_scan_ratio(zone, sc, percent);
for_each_evictable_lru(l) {
int file = is_file_lru(l);
unsigned long scan;
scan = zone_nr_pages(zone, sc, l);
- if (priority) {
+ if (priority || noswap) {
scan >>= priority;
scan = (scan * percent[file]) / 100;
}