From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 28 Nov 2008 06:08:03 -0500 From: Rik van Riel Subject: [PATCH] vmscan: skip freeing memory from zones with lots free Message-ID: <20081128060803.73cd59bd@bree.surriel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, KOSAKI Motohiro , akpm@linux-foundation.org List-ID: Skip freeing memory from zones that already have lots of free memory. If one memory zone has harder to free memory, we want to avoid freeing excessive amounts of memory from other zones, if only because pageout IO from the other zones can slow down page freeing from the problem zone. This is similar to the check already done by kswapd in balance_pgdat(). Signed-off-by: Rik van Riel --- Kosaki-san, this should address point (3) from your list. mm/vmscan.c | 3 +++ 1 file changed, 3 insertions(+) Index: linux-2.6.28-rc5/mm/vmscan.c =================================================================== --- linux-2.6.28-rc5.orig/mm/vmscan.c 2008-11-28 05:53:56.000000000 -0500 +++ linux-2.6.28-rc5/mm/vmscan.c 2008-11-28 06:05:29.000000000 -0500 @@ -1510,6 +1510,9 @@ static unsigned long shrink_zones(int pr if (zone_is_all_unreclaimable(zone) && priority != DEF_PRIORITY) continue; /* Let kswapd poll it */ + if (zone_watermark_ok(zone, sc->order, + 4*zone->pages_high, high_zoneidx, 0)) + continue; /* Lots free already */ sc->all_unreclaimable = 0; } else { /* -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org