From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 390D66B004F for ; Tue, 9 Jun 2009 07:59:14 -0400 (EDT) Date: Tue, 9 Jun 2009 14:35:36 +0200 From: Nick Piggin Subject: Re: [PATCH] [6/16] HWPOISON: Add various poison checks in mm/memory.c Message-ID: <20090609123536.GA15219@wotan.suse.de> References: <20090603846.816684333@firstfloor.org> <20090603184639.1933B1D028F@basil.firstfloor.org> <20090609102504.GH14820@wotan.suse.de> <20090609122131.GC5589@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090609122131.GC5589@localhost> Sender: owner-linux-mm@kvack.org To: Wu Fengguang Cc: Andi Kleen , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" List-ID: On Tue, Jun 09, 2009 at 08:21:31PM +0800, Wu Fengguang wrote: > 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. Yes I didn't see some of your review comments and made some of these comments first. If this is gone then I'm happy :) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org