Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754131AbZFDFMM (ORCPT ); Thu, 4 Jun 2009 01:12:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752147AbZFDFL6 (ORCPT ); Thu, 4 Jun 2009 01:11:58 -0400 Received: from one.firstfloor.org ([213.235.205.2]:48352 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751545AbZFDFL6 (ORCPT ); Thu, 4 Jun 2009 01:11:58 -0400 Date: Thu, 4 Jun 2009 07:19:15 +0200 From: Andi Kleen To: Wu Fengguang Cc: Andi Kleen , "akpm@linux-foundation.org" , "npiggin@suse.de" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" Subject: Re: [PATCH] [6/16] HWPOISON: Add various poison checks in mm/memory.c Message-ID: <20090604051915.GN1065@one.firstfloor.org> References: <20090603846.816684333@firstfloor.org> <20090603184639.1933B1D028F@basil.firstfloor.org> <20090604042603.GA15682@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090604042603.GA15682@localhost> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1296 Lines: 37 On Thu, Jun 04, 2009 at 12:26:03PM +0800, Wu Fengguang wrote: > On Thu, Jun 04, 2009 at 02:46:38AM +0800, Andi Kleen wrote: > > > > Bail out early when hardware poisoned pages are found in page fault handling. > > I suspect this patch is also not absolutely necessary: the poisoned > page will normally have been isolated already. It's needed to prevent new pages comming in when there is a parallel fault while the memory failure handling is in process. Otherwise the pages could get remapped in that small window. > > --- linux.orig/mm/memory.c 2009-06-03 19:36:23.000000000 +0200 > > +++ linux/mm/memory.c 2009-06-03 19:36:23.000000000 +0200 > > @@ -2797,6 +2797,9 @@ > > if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) > > return ret; > > > > + if (unlikely(PageHWPoison(vmf.page))) > > + return VM_FAULT_HWPOISON; > > + > > Direct return with locked page could lockup someone later. > Either drop this patch or fix it with this check? Fair point. Fixed. Thanks, -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/