From b39415b2731d7dec5e612d2d12595da82399eedf Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Mon, 14 Dec 2009 17:59:48 -0800 Subject: [PATCH] vmscan: do not evict inactive pages when skipping an active list scan In AIM7 runs, recent kernels start swapping out anonymous pages well before they should. This is due to shrink_list falling through to shrink_inactive_list if !inactive_anon_is_low(zone, sc), when all we really wanted to do is pre-age some anonymous pages to give them extra time to be referenced while on the inactive list. The obvious fix is to make sure that shrink_list does not fall through to scanning/reclaiming inactive pages when we called it to scan one of the active lists. This change should be safe because the loop in shrink_zone ensures that we will still shrink the anon and file inactive lists whenever we should. [kosaki.motohiro@jp.fujitsu.com: inactive_file_is_low() should be inactive_anon_is_low()] Reported-by: Larry Woodman Signed-off-by: Rik van Riel Acked-by: Johannes Weiner Cc: Tomasz Chmielewski Signed-off-by: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 2ef59d5b16a6..04658189b9a5 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1463,20 +1463,26 @@ static int inactive_file_is_low(struct zone *zone, struct scan_control *sc) return low; } +static int inactive_list_is_low(struct zone *zone, struct scan_control *sc, + int file) +{ + if (file) + return inactive_file_is_low(zone, sc); + else + return inactive_anon_is_low(zone, sc); +} + static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan, struct zone *zone, struct scan_control *sc, int priority) { int file = is_file_lru(lru); - if (lru == LRU_ACTIVE_FILE && inactive_file_is_low(zone, sc)) { - shrink_active_list(nr_to_scan, zone, sc, priority, file); + if (is_active_lru(lru)) { + if (inactive_list_is_low(zone, sc, file)) + shrink_active_list(nr_to_scan, zone, sc, priority, file); return 0; } - if (lru == LRU_ACTIVE_ANON && inactive_anon_is_low(zone, sc)) { - shrink_active_list(nr_to_scan, zone, sc, priority, file); - return 0; - } return shrink_inactive_list(nr_to_scan, zone, sc, priority, file); } -- 2.20.1