Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755881Ab1CWRcK (ORCPT ); Wed, 23 Mar 2011 13:32:10 -0400 Received: from one.firstfloor.org ([213.235.205.2]:36647 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755176Ab1CWRcI (ORCPT ); Wed, 23 Mar 2011 13:32:08 -0400 Date: Wed, 23 Mar 2011 18:32:06 +0100 From: Andi Kleen To: "K.Prasad" Cc: Andrea Arcangeli , Andi Kleen , Hidetoshi Seto , Andrew Morton , Huang Ying , Jin Dongming , linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli , Srivatsa Vaddagiri , hughd@google.com Subject: Re: [PATCH 3/4] Check whether pages are poisoned before copying Message-ID: <20110323173206.GG21838@one.firstfloor.org> References: <4D817234.9070106@jp.fujitsu.com> <4D8172D7.3040201@jp.fujitsu.com> <20110317041424.GD11094@one.firstfloor.org> <4D819A2A.8050606@jp.fujitsu.com> <20110317062612.GE11094@one.firstfloor.org> <4D81BB87.10803@jp.fujitsu.com> <20110317140401.GX10696@random.random> <20110323172616.GA2170@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110323172616.GA2170@in.ibm.com> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1021 Lines: 24 > On an extended note, I don't understand why hwpoison code should not > handle Ksm pages the same way as other user-space pages. While it is Noone has done the work for it so far. However we did some evaluation some time ago with some simple KVM setups and it turned out KSM was only very little physical memory overall (< few percent) Normally it's better to focus on areas with more payoff (= more memory), unless you can find a workload where KSM is actually significant. > It appears that the restriction for PageKsm() can be removed from > memory-failure.c code without making the races any better or worse. Any > opinions on that? I don't know. The KSM code paths would need to be audited first. Hugh added the checks originally and may have an opinion. -Andi -- 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/