From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx127.postini.com [74.125.245.127]) by kanga.kvack.org (Postfix) with SMTP id D45236B0034 for ; Tue, 11 Jun 2013 18:20:12 -0400 (EDT) Received: by mail-pd0-f182.google.com with SMTP id r10so3028695pdi.27 for ; Tue, 11 Jun 2013 15:20:12 -0700 (PDT) Date: Tue, 11 Jun 2013 15:20:09 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH v2] Make transparent hugepages cpuset aware In-Reply-To: <1370967244-5610-1-git-send-email-athorlton@sgi.com> Message-ID: References: <1370967244-5610-1-git-send-email-athorlton@sgi.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Alex Thorlton Cc: 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 Tue, 11 Jun 2013, Alex Thorlton wrote: > This patch adds the ability to control THPs on a per cpuset basis. Please see > the additions to Documentation/cgroups/cpusets.txt for more information. > What's missing from both this changelog and the documentation you point to is why this change is needed. I can understand how you would want a subset of processes to not use thp when it is enabled. This is typically where MADV_NOHUGEPAGE is used with some type of malloc hook. I don't think we need to do this on a cpuset level, so unfortunately I think this needs to be reworked. Would it make sense to add a per-process tunable to always get MADV_NOHUGEPAGE behavior for all of its sbrk() and mmap() calls? Perhaps, but then you would need to justify why it can't be done with a malloc hook in userspace. This seems to just be working around a userspace issue or for a matter of convenience, right? -- 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