From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 8A3DF6B0047 for ; Tue, 21 Apr 2009 03:39:30 -0400 (EDT) Received: by ti-out-0910.google.com with SMTP id a21so1541704tia.8 for ; Tue, 21 Apr 2009 00:40:05 -0700 (PDT) Date: Tue, 21 Apr 2009 16:39:54 +0900 From: Minchan Kim Subject: Re: [PATCH] low order lumpy reclaim also should use PAGEOUT_IO_SYNC. Message-Id: <20090421163954.eabf5543.minchan.kim@barrios-desktop> In-Reply-To: <20090421161829.F139.A69D9226@jp.fujitsu.com> References: <20090421142056.F127.A69D9226@jp.fujitsu.com> <20090421161219.e13a928d.minchan.kim@barrios-desktop> <20090421161829.F139.A69D9226@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Minchan Kim , Andy Whitcroft , Peter Zijlstra , Mel Gorman , Rik van Riel , LKML , linux-mm , Andrew Morton , Lee Schermerhorn List-ID: On Tue, 21 Apr 2009 16:21:18 +0900 (JST) KOSAKI Motohiro wrote: > > Hi, Kosaki-san. > > > > On Tue, 21 Apr 2009 14:22:27 +0900 (JST) > > KOSAKI Motohiro wrote: > > > > > Subject: [PATCH] low order lumpy reclaim also should use PAGEOUT_IO_SYNC. > > > > > > commit 33c120ed2843090e2bd316de1588b8bf8b96cbde (more aggressively use lumpy reclaim) > > > change lumpy reclaim using condition. but it isn't enough change. > > > > > > lumpy reclaim don't only mean isolate neighber page, but also do pageout as synchronous. > > > this patch does it. > > > > I agree. > > > > Andi added synchronous lumpy reclaim with c661b078fd62abe06fd11fab4ac5e4eeafe26b6d. > > At that time, lumpy reclaim is not agressive. > > His intension is just for high-order users.(above PAGE_ALLOC_COSTLY_ORDER). > > > > After some time, Rik added aggressive lumpy reclaim with 33c120ed2843090e2bd316de1588b8bf8b96cbde. > > His intension is that do lumpy reclaim when high-order users and trouble getting a small set of contiguous pages. > > > > So we also have to add synchronous pageout for small set of contiguous pages. > > Nice catch!. > > > > Reviewed-by: Minchan Kim > > > > BTW, Do you have any number ? > > No. > > Actually, this logic only run when system is strongly memory stavation > or fragment. not normal case. > > At that time, another slowdown thing hide synchronous reclaim latency, I think. > Yes. I think it's hard measure, too. I was just out of curiosity if server guy have a any benchmark method. ;-) -- Kinds Regards Minchan Kim -- 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