From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] vmscan: skip freeing memory from zones with lots free From: Peter Zijlstra In-Reply-To: <20081128060803.73cd59bd@bree.surriel.com> References: <20081128060803.73cd59bd@bree.surriel.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Fri, 28 Nov 2008 12:30:14 +0100 Message-Id: <1227871814.4454.3855.camel@twins> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, KOSAKI Motohiro , akpm@linux-foundation.org List-ID: On Fri, 2008-11-28 at 06:08 -0500, Rik van Riel wrote: > 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 Make sense, Acked-by: Peter Zijlstra > --- > 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 -- 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