memcg: add the soft_limit reclaim in global direct reclaim.

We recently added the change in global background reclaim which counts the
return value of soft_limit reclaim.  Now this patch adds the similar logic
on global direct reclaim.

We should skip scanning global LRU on shrink_zone if soft_limit reclaim
does enough work.  This is the first step where we start with counting the
nr_scanned and nr_reclaimed from soft_limit reclaim into global
scan_control.

Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 2 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 9ce6ec84328e..884ae08c16cc 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1977,11 +1977,14 @@ restart:
  * If a zone is deemed to be full of pinned pages then just give it a light
  * scan then give up on it.
  */
-static void shrink_zones(int priority, struct zonelist *zonelist,
+static unsigned long shrink_zones(int priority, struct zonelist *zonelist,
                                         struct scan_control *sc)
 {
         struct zoneref *z;
         struct zone *zone;
+        unsigned long nr_soft_reclaimed;
+        unsigned long nr_soft_scanned;
+        unsigned long total_scanned = 0;
 
         for_each_zone_zonelist_nodemask(zone, z, zonelist,
                                         gfp_zone(sc->gfp_mask), sc->nodemask) {
@@ -1998,8 +2001,17 @@ static void shrink_zones(int priority, struct zonelist *zonelist,
                                 continue;       /* Let kswapd poll it */
                 }
 
+                nr_soft_scanned = 0;
+                nr_soft_reclaimed = mem_cgroup_soft_limit_reclaim(zone,
+                                                        sc->order, sc->gfp_mask,
+                                                        &nr_soft_scanned);
+                sc->nr_reclaimed += nr_soft_reclaimed;
+                total_scanned += nr_soft_scanned;
+
                 shrink_zone(priority, zone, sc);
         }
+
+        return total_scanned;
 }
 
 static bool zone_reclaimable(struct zone *zone)
@@ -2064,7 +2076,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
                 sc->nr_scanned = 0;
                 if (!priority)
                         disable_swap_token();
-                shrink_zones(priority, zonelist, sc);
+                total_scanned += shrink_zones(priority, zonelist, sc);
                 /*
                  * Don't shrink slabs when reclaiming memory from
                  * over limit cgroups