[PATCH] mm: vmscan: reclaim highmem zone if buffer_heads is over limit

From: Minchan Kim
Date: Fri Apr 01 2016 - 03:59:18 EST


We have been reclaimed highmem zone if buffer_heads is over limit
but [1] changed the behavior so it doesn't reclaim highmem zone
although buffer_heads is over the limit.
This patch restores the logic.

As well, [2] removed classzone_idx so we don't need code related to
it. This patch cleans it up.

[1] commit 6b4f7799c6a5 ("mm: vmscan: invoke slab shrinkers from shrink_zone()")
[2] commit 5acbd3bfc93b ("mm, oom: rework oom detection")

Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
mm/vmscan.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index c7696a2e11c7..6e67de2a61ed 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2550,17 +2550,9 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc)
sc->gfp_mask |= __GFP_HIGHMEM;

for_each_zone_zonelist_nodemask(zone, z, zonelist,
- requested_highidx, sc->nodemask) {
- enum zone_type classzone_idx;
-
+ gfp_zone(sc->gfp_mask), sc->nodemask) {
if (!populated_zone(zone))
continue;
-
- classzone_idx = requested_highidx;
- while (!populated_zone(zone->zone_pgdat->node_zones +
- classzone_idx))
- classzone_idx--;
-
/*
* Take care memory controller reclaiming has small influence
* to global LRU.
--
1.9.1