[PATCH 25/97] mm: vmscan: call NUMA-unaware shrinkers irrespective of nodemask

From: Mel Gorman
Date: Thu Aug 28 2014 - 15:07:07 EST


From: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>

commit ec97097bca147d5718a5d2c024d1ec740b10096d upstream.

If a shrinker is not NUMA-aware, shrink_slab() should call it exactly
once with nid=0, but currently it is not true: if node 0 is not set in
the nodemask or if it is not online, we will not call such shrinkers at
all. As a result some slabs will be left untouched under some
circumstances. Let us fix it.

Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
Reported-by: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Glauber Costa <glommer@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
---
mm/vmscan.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0506995..e36294b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -369,16 +369,17 @@ unsigned long shrink_slab(struct shrink_control *shrinkctl,
}

list_for_each_entry(shrinker, &shrinker_list, list) {
- for_each_node_mask(shrinkctl->nid, shrinkctl->nodes_to_scan) {
- if (!node_online(shrinkctl->nid))
- continue;
-
- if (!(shrinker->flags & SHRINKER_NUMA_AWARE) &&
- (shrinkctl->nid != 0))
- break;
-
+ if (!(shrinker->flags & SHRINKER_NUMA_AWARE)) {
+ shrinkctl->nid = 0;
freed += shrink_slab_node(shrinkctl, shrinker,
- nr_pages_scanned, lru_pages);
+ nr_pages_scanned, lru_pages);
+ continue;
+ }
+
+ for_each_node_mask(shrinkctl->nid, shrinkctl->nodes_to_scan) {
+ if (node_online(shrinkctl->nid))
+ freed += shrink_slab_node(shrinkctl, shrinker,
+ nr_pages_scanned, lru_pages);

}
}
--
1.8.4.5

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