From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx109.postini.com [74.125.245.109]) by kanga.kvack.org (Postfix) with SMTP id E5B7B6B0033 for ; Wed, 19 Jun 2013 22:43:26 -0400 (EDT) Received: by mail-pa0-f44.google.com with SMTP id lj1so5806737pab.17 for ; Wed, 19 Jun 2013 19:43:26 -0700 (PDT) Date: Wed, 19 Jun 2013 19:43:23 -0700 (PDT) From: David Rientjes 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> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: 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 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, 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