Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935609Ab3FTCn2 (ORCPT ); Wed, 19 Jun 2013 22:43:28 -0400 Received: from mail-pa0-f42.google.com ([209.85.220.42]:60510 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935506Ab3FTCn0 (ORCPT ); Wed, 19 Jun 2013 22:43:26 -0400 Date: Wed, 19 Jun 2013 19:43:23 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Robin Holt cc: Alex Thorlton , linux-kernel@vger.kernel.org, Li Zefan , Rob Landley , Andrew Morton , Mel Gorman , Rik van Riel , "Kirill A. Shutemov" , Johannes Weiner , Xiao Guangrong , linux-doc@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v2] Make transparent hugepages cpuset aware In-Reply-To: <20130620022739.GF3658@sgi.com> Message-ID: References: <1370967244-5610-1-git-send-email-athorlton@sgi.com> <20130618164537.GJ16067@sgi.com> <20130619093212.GX3658@sgi.com> <20130620022739.GF3658@sgi.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2153 Lines: 41 On Wed, 19 Jun 2013, Robin Holt wrote: > cpusets was not for NUMA. It has no preference for "nodes" or anything like > that. It was for splitting a machine into layered smaller groups. Usually, > we see one cpuset with contains the batch scheduler. The batch scheduler then > creates cpusets for jobs it starts. Has nothing to do with nodes. That is > more an administrator issue. They set the minimum grouping of resources > for scheduled jobs. > I disagree with all of the above, it's not what Paul Jackson developed cpusets for, it's not what he wrote in Documentation/cgroups/cpusets.txt, and it's not why libnuma immediately supported it. Cpusets is for NUMA, like it or not. > > I'm saying there's absolutely no reason to have thp controlled by a > > cpuset, or ANY cgroup for that matter, since you chose not to respond to > > the question I asked: why do you want to control thp behavior for certain > > static binaries and not others? Where is the performance regression or > > the downside? Is it because of max_ptes_none for certain jobs blowing up > > the rss? We need information, and even if were justifiable then it > > wouldn't have anything to do with ANY cgroup but rather a per-process > > control. It has nothing to do with cpusets whatsoever. > > It was a request from our benchmarking group that has found some jobs > benefit from thp, while other are harmed. Let me ask them for more > details. > Yes, please, because if some jobs are harmed by thp then we need to fix that regression and not paper around with it with some cpuset-based solution. People should be able to run with CONFIG_TRANSPARENT_HUGEPAGE enabled and not be required to enable CONFIG_CPUSETS for optimal behavior. I'm suspecting that you're referring to enlarged rss because of khugepaged's max_ptes_none and because you're abusing the purpose of cpusets for containerization. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/