From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.18.234]) by e23smtp03.au.ibm.com (8.13.1/8.13.1) with ESMTP id m1R58lmN026943 for ; Wed, 27 Feb 2008 16:08:47 +1100 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id m1R59KcA352464 for ; Wed, 27 Feb 2008 16:09:21 +1100 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m1R59O9u005630 for ; Wed, 27 Feb 2008 16:09:25 +1100 Message-ID: <47C4EF2D.90508@linux.vnet.ibm.com> Date: Wed, 27 Feb 2008 10:33:41 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com MIME-Version: 1.0 Subject: Re: [RFC][PATCH] page reclaim throttle take2 References: <20080227133850.4249.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20080227140042.66abb805.kamezawa.hiroyu@jp.fujitsu.com> <20080227140221.424C.KOSAKI.MOTOHIRO@jp.fujitsu.com> In-Reply-To: <20080227140221.424C.KOSAKI.MOTOHIRO@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: KOSAKI Motohiro Cc: KAMEZAWA Hiroyuki , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Rik van Riel , Lee Schermerhorn , Nick Piggin List-ID: KOSAKI Motohiro wrote: > Hi > >>> I don't think so. >>> all modern many cpu machine stand on NUMA. >>> it mean following, >>> - if cpu increases, then zone increases, too. >>> >>> if default value increase by #cpus, lock contension dramatically increase >>> on large numa. >>> >>> Have I overlooked anything? >>> >> How about adding something like.. >> == >> CONFIG_SIMULTANEOUS_PAGE_RECLAIMERS >> int >> default 3 >> depends on DEBUG >> help >> This value determines the number of threads which can do page reclaim >> in a zone simultaneously. If this is too big, performance under heavy memory >> pressure will decrease. >> If unsure, use default. >> == >> >> Then, you can get performance reports from people interested in this >> feature in test cycle. > > hm, intersting. > but sysctl parameter is more better, i think. > > OK, I'll add it at next post. I think sysctl should be interesting. The config option provides good documentation, but it is static in nature (requires reboot to change). I wish we could have the best of both worlds. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL -- 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