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authorMichal Hocko <mhocko@suse.cz>2013-09-12 15:13:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-12 15:38:00 -0700
commitde57780dc659f95b17ccb649f003278dde0b5b86 (patch)
treed2493cc412c16946f3ead9158a61b26dd1f0c45a /mm/vmscan.c
parenta5b7c87f92076352dbff2fe0423ec255e1c9a71b (diff)
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memcg: enhance memcg iterator to support predicates
The caller of the iterator might know that some nodes or even subtrees should be skipped but there is no way to tell iterators about that so the only choice left is to let iterators to visit each node and do the selection outside of the iterating code. This, however, doesn't scale well with hierarchies with many groups where only few groups are interesting. This patch adds mem_cgroup_iter_cond variant of the iterator with a callback which gets called for every visited node. There are three possible ways how the callback can influence the walk. Either the node is visited, it is skipped but the tree walk continues down the tree or the whole subtree of the current group is skipped. [hughd@google.com: fix memcg-less page reclaim] Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
-rw-r--r--mm/vmscan.c16
1 files changed, 5 insertions, 11 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1896e7ca494b..f2e35099508b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2151,21 +2151,16 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim)
.zone = zone,
.priority = sc->priority,
};
- struct mem_cgroup *memcg;
+ struct mem_cgroup *memcg = NULL;
+ mem_cgroup_iter_filter filter = (soft_reclaim) ?
+ mem_cgroup_soft_reclaim_eligible : NULL;
nr_reclaimed = sc->nr_reclaimed;
nr_scanned = sc->nr_scanned;
- memcg = mem_cgroup_iter(root, NULL, &reclaim);
- do {
+ while ((memcg = mem_cgroup_iter_cond(root, memcg, &reclaim, filter))) {
struct lruvec *lruvec;
- if (soft_reclaim &&
- !mem_cgroup_soft_reclaim_eligible(memcg, root)) {
- memcg = mem_cgroup_iter(root, memcg, &reclaim);
- continue;
- }
-
lruvec = mem_cgroup_zone_lruvec(zone, memcg);
shrink_lruvec(lruvec, sc);
@@ -2185,8 +2180,7 @@ __shrink_zone(struct zone *zone, struct scan_control *sc, bool soft_reclaim)
mem_cgroup_iter_break(root, memcg);
break;
}
- memcg = mem_cgroup_iter(root, memcg, &reclaim);
- } while (memcg);
+ }
vmpressure(sc->gfp_mask, sc->target_mem_cgroup,
sc->nr_scanned - nr_scanned,