Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755075AbZFEHjd (ORCPT ); Fri, 5 Jun 2009 03:39:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752502AbZFEHj0 (ORCPT ); Fri, 5 Jun 2009 03:39:26 -0400 Received: from ganesha.gnumonks.org ([213.95.27.120]:53870 "EHLO ganesha.gnumonks.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750905AbZFEHj0 (ORCPT ); Fri, 5 Jun 2009 03:39:26 -0400 Date: Fri, 5 Jun 2009 09:30:18 +0200 From: Harald Welte To: Andi Kleen Cc: "Michael S. Zick" , Linus Torvalds , Duane Griffin , Linux Kernel Mailing List Subject: Re: Linux 2.6.30-rc8 [also: VIA Support] Message-ID: <20090605073018.GH6411@prithivi.gnumonks.org> References: <200906041121.30845.lkml@morethan.org> <20090604174059.GB9823@prithivi.gnumonks.org> <873aaf4uvw.fsf@basil.nowhere.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <873aaf4uvw.fsf@basil.nowhere.org> 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: 1324 Lines: 28 On Thu, Jun 04, 2009 at 10:16:35PM +0200, Andi Kleen wrote: > Harald Welte writes: > > > > why would it matter on UP? as indicated, I'm not the expert here, but I thought > > memory ordering issues only arise in SMP systems [or possibly with regard to > > DMA, but as we already explored much earlier in this thread, drivers that access > > DMA buffers whil the hardware owns them are buggy and need to be fixed] > > Sorry we didn't establish that. Accessing data structures that are > also accessed by DMA hardware is pretty common in fact and memory > ordering issues also come up regularly (e.g. all the infamous PCI > posting bugs) > > What we established is that the drivers don't use LOCK for it > (or at least we think that's very unlikely) Yes, sorry for not mentioning that. I was implicitly thinking of "not using an appropriate locking method" -- - Harald Welte http://linux.via.com.tw/ ============================================================================ VIA Free and Open Source Software Liaison -- 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/