Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759560AbZFIMVq (ORCPT ); Tue, 9 Jun 2009 08:21:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756890AbZFIMVh (ORCPT ); Tue, 9 Jun 2009 08:21:37 -0400 Received: from mga14.intel.com ([143.182.124.37]:19495 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756806AbZFIMVh (ORCPT ); Tue, 9 Jun 2009 08:21:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.41,331,1241420400"; d="scan'208";a="152234532" Date: Tue, 9 Jun 2009 20:21:31 +0800 From: Wu Fengguang To: Nick Piggin Cc: Andi Kleen , "akpm@linux-foundation.org" , "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: <20090609122131.GC5589@localhost> References: <20090603846.816684333@firstfloor.org> <20090603184639.1933B1D028F@basil.firstfloor.org> <20090609102504.GH14820@wotan.suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090609102504.GH14820@wotan.suse.de> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1556 Lines: 41 On Tue, Jun 09, 2009 at 06:25:04PM +0800, Nick Piggin wrote: > On Wed, Jun 03, 2009 at 08:46:38PM +0200, Andi Kleen wrote: > > > > Bail out early when hardware poisoned pages are found in page fault handling. > > Since they are poisoned they should not be mapped freshly into processes, > > because that would cause another (potentially deadly) machine check > > > > This is generally handled in the same way as OOM, just a different > > error code is returned to the architecture code. > > > > Signed-off-by: Andi Kleen > > > > --- > > mm/memory.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > Index: linux/mm/memory.c > > =================================================================== > > --- 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; > > Again, it would be nice if you just worry about this in your MCE > handler and don't sprinkle things like this in fastpaths. For this patch, I cannot imagine a clear usage case for it, and proposed to remove it until there comes a case. Thanks, Fengguang -- 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/