From 7c5bd705d8f983ae1868a126956f5aa3a6702e3f Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Fri, 22 Feb 2013 16:32:10 -0800
Subject: [PATCH] mm: memcg: only evict file pages when we have plenty
Commit e9868505987a ("mm, vmscan: only evict file pages when we have
plenty") makes a point of not going for anonymous memory while there is
still enough inactive cache around.
The check was added only for global reclaim, but it is just as useful to
reduce swapping in memory cgroup reclaim:
200M-memcg-defconfig-j2
vanilla patched
Real time 454.06 ( +0.00%) 453.71 ( -0.08%)
User time 668.57 ( +0.00%) 668.73 ( +0.02%)
System time 128.92 ( +0.00%) 129.53 ( +0.46%)
Swap in 1246.80 ( +0.00%) 814.40 ( -34.65%)
Swap out 1198.90 ( +0.00%) 827.00 ( -30.99%)
Pages allocated 16431288.10 ( +0.00%) 16434035.30 ( +0.02%)
Major faults 681.50 ( +0.00%) 593.70 ( -12.86%)
THP faults 237.20 ( +0.00%) 242.40 ( +2.18%)
THP collapse 241.20 ( +0.00%) 248.50 ( +3.01%)
THP splits 157.30 ( +0.00%) 161.40 ( +2.59%)
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Simon Jeons <simon.jeons@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/vmscan.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 196709f5ee58..ff842d9a7714 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1700,18 +1700,20 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
fraction[1] = 0;
denominator = 1;
goto out;
- } else if (!inactive_file_is_low_global(zone)) {
- /*
- * There is enough inactive page cache, do not
- * reclaim anything from the working set right now.
- */
- fraction[0] = 0;
- fraction[1] = 1;
- denominator = 1;
- goto out;
}
}
+ /*
+ * There is enough inactive page cache, do not reclaim
+ * anything from the anonymous working set right now.
+ */
+ if (!inactive_file_is_low(lruvec)) {
+ fraction[0] = 0;
+ fraction[1] = 1;
+ denominator = 1;
+ goto out;
+ }
+
/*
* With swappiness at 100, anonymous and file have the same priority.
* This scanning priority is essentially the inverse of IO cost.