From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balbir Singh Subject: Re: [PATCH 0/3] Unmapped page cache control (v5) Date: Fri, 1 Apr 2011 18:42:15 +0530 Message-ID: <20110401131214.GS2879@balbir.in.ibm.com> References: <20110331144145.0ECA.A69D9226@jp.fujitsu.com> <20110331082813.GN2879@balbir.in.ibm.com> <20110401165752.A889.A69D9226@jp.fujitsu.com> Reply-To: balbir@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: linux-mm@kvack.org, akpm@linux-foundation.org, npiggin@kernel.dk, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, cl@linux.com, kamezawa.hiroyu@jp.fujitsu.com, Mel Gorman , Minchan Kim To: KOSAKI Motohiro Return-path: Content-Disposition: inline In-Reply-To: <20110401165752.A889.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org List-Id: kvm.vger.kernel.org * KOSAKI Motohiro [2011-04-01 16:56:57]: > Hi > > > > 1) zone reclaim doesn't work if the system has multiple node and the > > > workload is file cache oriented (eg file server, web server, mail server, et al). > > > because zone recliam make some much free pages than zone->pages_min and > > > then new page cache request consume nearest node memory and then it > > > bring next zone reclaim. Then, memory utilization is reduced and > > > unnecessary LRU discard is increased dramatically. > > > > > > SGI folks added CPUSET specific solution in past. (cpuset.memory_spread_page) > > > But global recliam still have its issue. zone recliam is HPC workload specific > > > feature and HPC folks has no motivation to don't use CPUSET. > > > > I am afraid you misread the patches and the intent. The intent to > > explictly enable control of unmapped pages and has nothing > > specifically to do with multiple nodes at this point. The control is > > system wide and carefully enabled by the administrator. > > Hm. OK, I may misread. > Can you please explain the reason why de-duplication feature need to selectable and > disabled by defaut. "explicity enable" mean this feature want to spot corner case issue?? > Yes, because given a selection of choices (including what you mentioned in the review), it would be nice to have this selectable. -- Three Cheers, Balbir -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org