[PATCH 4/4] mm: vmscan: If kswapd has been running too long, allow it to sleep
From: Mel Gorman <mgorman@suse.de>
Date: 2011-05-13 14:03:33
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
memory management, memory management - mglru (multi-gen lru), memory management - reclaim, the rest · Maintainers:
Andrew Morton, Johannes Weiner, Linus Torvalds
Under constant allocation pressure, kswapd can be in the situation where sleeping_prematurely() will always return true even if kswapd has been running a long time. Check if kswapd needs to be scheduled. Signed-off-by: Mel Gorman <mgorman@suse.de> --- mm/vmscan.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index af24d1e..4d24828 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c@@ -2251,6 +2251,10 @@ static bool sleeping_prematurely(pg_data_t *pgdat, int order, long remaining, unsigned long balanced = 0; bool all_zones_ok = true; + /* If kswapd has been running too long, just sleep */ + if (need_resched()) + return false; + /* If a direct reclaimer woke kswapd within HZ/10, it's premature */ if (remaining) return true;
--
1.7.3.4