Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754377Ab2ECGzm (ORCPT ); Thu, 3 May 2012 02:55:42 -0400 Received: from shards.monkeyblade.net ([198.137.202.13]:40423 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753807Ab2ECGzl (ORCPT ); Thu, 3 May 2012 02:55:41 -0400 Date: Thu, 03 May 2012 02:54:27 -0400 (EDT) Message-Id: <20120503.025427.1277785208536786257.davem@davemloft.net> To: hpa@zytor.com Cc: torvalds@linux-foundation.org, npiggin@gmail.com, jana@saout.de, jlbec@evilplan.org, linux-kernel@vger.kernel.org Subject: Re: Oops with DCACHE_WORD_ACCESS and ocfs2, autofs4 From: David Miller In-Reply-To: <4FA227FB.7060709@zytor.com> References: <4FA227FB.7060709@zytor.com> X-Mailer: Mew version 6.5 on Emacs 24.0.95 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Wed, 02 May 2012 23:54:29 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 983 Lines: 23 From: "H. Peter Anvin" Date: Wed, 02 May 2012 23:38:51 -0700 > On 05/02/2012 10:57 PM, Linus Torvalds wrote: >> >> There are multiple ways to fix this, including just marking that >> unaligned word access as being able to take an exception, but I had >> hoped to avoid having to do that. There are alternatives, like always >> padding allocations up by 7 bytes, but those are nasty too. So I'd >> like to understand what triggers this for Jana, it's possible we can >> just work around that particular issue. >> > > Can we do the trick of aligning the pointer and ignoring the start? > That would allow even architectures that don't have unaligned accesses > to work, too. Doing that would flub the hash computation. -- 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/