Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759660AbXJDSK6 (ORCPT ); Thu, 4 Oct 2007 14:10:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755759AbXJDSKv (ORCPT ); Thu, 4 Oct 2007 14:10:51 -0400 Received: from mx1.redhat.com ([66.187.233.31]:51329 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754697AbXJDSKu (ORCPT ); Thu, 4 Oct 2007 14:10:50 -0400 Date: Thu, 4 Oct 2007 14:10:44 -0400 From: Dave Jones To: Andi Kleen Cc: Nick Piggin , Linux Kernel Mailing List , Linus Torvalds Subject: Re: [rfc][patch 2/3] x86: fix IO write barriers Message-ID: <20071004181044.GA23300@redhat.com> Mail-Followup-To: Dave Jones , Andi Kleen , Nick Piggin , Linux Kernel Mailing List , Linus Torvalds References: <20071004052153.GA15131@wotan.suse.de> <20071004052258.GB15131@wotan.suse.de> <20071004173203.GC5828@redhat.com> <200710041953.16656.ak@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200710041953.16656.ak@suse.de> User-Agent: Mutt/1.5.14 (2007-02-12) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1197 Lines: 32 On Thu, Oct 04, 2007 at 07:53:16PM +0200, Andi Kleen wrote: > > > The only vendor that ever implemented OOSTOREs was Centaur, and they > > only did in the Winchip generation of the CPUs. When they dropped it > > from the C3, I asked whether they intended to bring it back, and the > > answer was "extremely unlikely". > > > > Do you know if it made a big performance difference? On the winchip, it was a huge win. I can't remember exact numbers, but pretty much every benchmark I threw at it at the time showed significant improvement. > But yes we should probably just remove this special case to make > maintenance easier. It's CONFIG_SMP anyway, which none of the winchips were. SMP+OOSTORE just didn't happen, and I'd be surprised if any vendor makes it happen any time soon. (Even if so, it's likely we'd need to make additional changes anyway, so adding it back shouldn't be a big deal.) Dave -- http://www.codemonkey.org.uk - 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/