From linux-fsdevel-owner@vger.kernel.org Fri May 13 10:03:52 2011 From: Mel Gorman To: Andrew Morton Cc: James Bottomley , Colin King , Raghavendra D Prabhu , Jan Kara , Chris Mason , Christoph Lameter , Pekka Enberg , Rik van Riel , Johannes Weiner , linux-fsdevel , linux-mm , linux-kernel , linux-ext4 , Mel Gorman Subject: [PATCH 4/4] mm: vmscan: If kswapd has been running too long, allow it to sleep Date: Fri, 13 May 2011 15:03:24 +0100 Message-Id: <1305295404-12129-5-git-send-email-mgorman@suse.de> X-Mailing-List: linux-fsdevel@vger.kernel.org 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 --- 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