Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757569Ab3FKWUS (ORCPT ); Tue, 11 Jun 2013 18:20:18 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:37116 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756433Ab3FKWUM (ORCPT ); Tue, 11 Jun 2013 18:20:12 -0400 Date: Tue, 11 Jun 2013 15:20:09 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com 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 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> 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: 1163 Lines: 26 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 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/