Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757928AbZFLMjm (ORCPT ); Fri, 12 Jun 2009 08:39:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754434AbZFLMje (ORCPT ); Fri, 12 Jun 2009 08:39:34 -0400 Received: from mail4-relais-sop.national.inria.fr ([192.134.164.105]:21661 "EHLO mail4-relais-sop.national.inria.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750783AbZFLMjd (ORCPT ); Fri, 12 Jun 2009 08:39:33 -0400 X-Greylist: delayed 597 seconds by postgrey-1.27 at vger.kernel.org; Fri, 12 Jun 2009 08:39:32 EDT X-IronPort-AV: E=Sophos;i="4.42,209,1243807200"; d="scan'208";a="41643759" Message-ID: <4A324A4E.1060405@inria.fr> Date: Fri, 12 Jun 2009 14:30:06 +0200 From: Brice Goglin User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 To: Stefan Lankes CC: "'Andi Kleen'" , linux-kernel@vger.kernel.org, Lee.Schermerhorn@hp.com, linux-numa@vger.kernel.org, Boris Bierbaum Subject: Re: [RFC PATCH 0/4]: affinity-on-next-touch References: <000c01c9d212$4c244720$e46cd560$@rwth-aachen.de> <87zldjn597.fsf@basil.nowhere.org> <000001c9eac4$cb8b6690$62a233b0$@rwth-aachen.de> <20090612103251.GJ25568@one.firstfloor.org> <004001c9eb53$71991300$54cb3900$@rwth-aachen.de> In-Reply-To: <004001c9eb53$71991300$54cb3900$@rwth-aachen.de> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1134 Lines: 26 Stefan Lankes wrote: > He enables the support of migration-on-fault via cpusets (echo 1 > > /dev/cpuset/migrate_on_fault). > Afterwards, every process could initiate migration-on-fault via mbind(..., > MPOL_MF_MOVE|MPOL_MF_LAZY). So mbind(MPOL_MF_LAZY) is taking care of changing page protection so as to generate page-faults on next-touch? (instead of your madvise) Is it migrating the whole memory area? Or only single pages? Then, what's happening with MPOL_MF_LAZY in the kernel? Is it actually stored in the mempolicy? If so, couldn't another fault later cause another migration? Or is MPOL_MF_LAZY filtered out of the policy once the protection of all PTE has been changed? I don't see why we need a new mempolicy here. If we are migrating single pages, migrate-on-next-touch looks like a page-attribute to me. There should be nothing to store in a mempolicy/VMA/whatever. Brice -- 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/