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 <lwoodman@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tomasz Chmielewski <mangoo@wpkg.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2ef59d5..0465818 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1463,20 +1463,26 @@
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);
}