[PATCH 4/8] mm: vmscan: Set zone flags before blocking

[Mel Gorman]

In shrink_page_list a decision may be made to stall and flag a zone
as ZONE_WRITEBACK so that if a large number of unqueued dirty pages are
encountered later then the reclaimer will stall. Set ZONE_WRITEBACK before
potentially going to sleep so it is noticed sooner.

Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
---
 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5b1a79c..5f80d01 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1445,8 +1445,8 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
 	 */
 	if (nr_writeback && nr_writeback >=
 			(nr_taken >> (DEF_PRIORITY - sc->priority))) {
-		wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10);
 		zone_set_flag(zone, ZONE_WRITEBACK);
+		wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10);
 	}
 
 	/*
-- 
1.8.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/