Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030211AbWCIA7X (ORCPT ); Wed, 8 Mar 2006 19:59:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030212AbWCIA7X (ORCPT ); Wed, 8 Mar 2006 19:59:23 -0500 Received: from detroit.securenet-server.net ([209.51.153.26]:16618 "EHLO detroit.securenet-server.net") by vger.kernel.org with ESMTP id S1030211AbWCIA7W (ORCPT ); Wed, 8 Mar 2006 19:59:22 -0500 From: Jesse Barnes To: Paul Mackerras Subject: Re: [PATCH] Document Linux's memory barriers [try #2] Date: Wed, 8 Mar 2006 16:59:05 -0800 User-Agent: KMail/1.9.1 Cc: Matthew Wilcox , Linus Torvalds , David Howells , Alan Cox , akpm@osdl.org, mingo@redhat.com, linux-arch@vger.kernel.org, linuxppc64-dev@ozlabs.org, linux-kernel@vger.kernel.org References: <20060308184500.GA17716@devserv.devel.redhat.com> <20060308194037.GO7301@parisc-linux.org> <17423.30924.278031.151438@cargo.ozlabs.ibm.com> In-Reply-To: <17423.30924.278031.151438@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200603081659.05786.jbarnes@virtuousgeek.org> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - detroit.securenet-server.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [47 12] X-AntiAbuse: Sender Address Domain - virtuousgeek.org X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 879 Lines: 21 On Wednesday, March 8, 2006 4:37 pm, Paul Mackerras wrote: > Matthew Wilcox writes: > > Looking at the SGI implementation, it's smarter than you think. > > Looks like there's a register in the local I/O hub that lets you > > determine when this write has been queued in the appropriate > > host->pci bridge. > > Given that mmiowb takes no arguments, how does it know which is the > appropriate PCI host bridge? It uses a per-node address space to reference the local bridge. The local bridge then waits until the remote bridge has acked the write before, then sets the outstanding write register to the appropriate value. Jesse - 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/