From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2992594AbXCBQbv (ORCPT ); Fri, 2 Mar 2007 11:31:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S2992593AbXCBQbv (ORCPT ); Fri, 2 Mar 2007 11:31:51 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:49234 "EHLO e34.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992592AbXCBQbu (ORCPT ); Fri, 2 Mar 2007 11:31:50 -0500 Message-ID: <45E8516B.5090203@austin.ibm.com> Date: Fri, 02 Mar 2007 10:31:39 -0600 From: Joel Schopp User-Agent: Thunderbird 1.5.0.9 (Windows/20061207) MIME-Version: 1.0 To: Mel Gorman CC: Bill Irwin , akpm@linux-foundation.org, npiggin@suse.de, clameter@engr.sgi.com, mingo@elte.hu, arjan@infradead.org, torvalds@osdl.org, mbligh@mbligh.org, Linux Memory Management List , Linux Kernel Mailing List Subject: Re: The performance and behaviour of the anti-fragmentation related patches References: <20070301101249.GA29351@skynet.ie> <20070302015235.GG10643@holomorphy.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >> Exhibiting a workload where the list patch breaks down and the zone >> patch rescues it might help if it's felt that the combination isn't as >> good as lists in isolation. I'm sure one can be dredged up somewhere. > > I can't think of a workload that totally makes a mess out of list-based. > However, list-based makes no guarantees on availability. If a system > administrator knows they need between 10,000 and 100,000 huge pages and > doesn't want to waste memory pinning too many huge pages at boot-time, > the zone-based mechanism would be what he wanted. From our testing with earlier versions of list based for memory hot-unplug on pSeries machines we were able to hot-unplug huge amounts of memory after running the nastiest workloads we could find for over a week. Without the patches we were unable to hot-unplug anything within minutes of running the same workloads. If something works for 99.999% of people (list based) and there is an easy way to configure it for the other 0.001% of the people ("zone" based) I call that a great solution. I really don't understand what the resistance is to these patches.