From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761421AbXGLJNq (ORCPT ); Thu, 12 Jul 2007 05:13:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753750AbXGLJNj (ORCPT ); Thu, 12 Jul 2007 05:13:39 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:33622 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752207AbXGLJNj (ORCPT ); Thu, 12 Jul 2007 05:13:39 -0400 Subject: Re: [PATCH 1/1] x86-64: introduce struct pci_sysdata to facilitate sharing of ->sysdata From: Arjan van de Ven To: Muli Ben-Yehuda Cc: Andi Kleen , Jeff Garzik , Yinghai Lu , Andrew Morton , Linux-Kernel , Jon Mason In-Reply-To: <20070712091029.GH4189@rhun.haifa.ibm.com> References: <20070711134514.GA4789@rhun.haifa.ibm.com> <1184203051.2693.3.camel@laptopd505.fenrus.org> <20070712091029.GH4189@rhun.haifa.ibm.com> Content-Type: text/plain Organization: Intel International BV Date: Thu, 12 Jul 2007 17:13:05 +0800 Message-Id: <1184231585.2720.8.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 (2.10.3-1.fc7) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2007-07-12 at 12:10 +0300, Muli Ben-Yehuda wrote: > On Thu, Jul 12, 2007 at 09:17:31AM +0800, Arjan van de Ven wrote: > > On Wed, 2007-07-11 at 16:45 +0300, Muli Ben-Yehuda wrote: > > > Andi, please consider applying for 2.6.23. Applies on top of the > > > Calgary update I just sent out ("Calgary: more updates for 2.6.23"). > > > > > > This patch introduces struct pci_sysdata to x86 and x86-64, and > > > converts the existing two users (NUMA, Calgary) to use it. > > > > > > This lays the groundwork for having other users of sysdata, such as > > > the PCI domains work. > > > > > > The Calgary bits are tested, the NUMA bits just look ok. > > > > I very much start to dislike the untyped "sysdata"... I much rather > > have separate fields for the different uses (like a IOMMU field) > > that aren't going to share ever. Possibly even typed, but for IOMMU > > that may be tricky.... > > Could you elaborate on what you mean here? > > If you mean instead of hanging a pci_sysdata off of struct pci_bus, > hang a 'void *iommu' and an 'int node' directly off of the pci_bus, yes that is what I mean. > that looks like a lot of churn (most architecture use sysdata as an > opaque pointer to an arch specific structure) and bloat (you would it's only a few bytes per pci device/bus. not all that bad for having something which involves splitting a shared pointer into logical users. (and heck, if you really really are worried we could make it a union for some of them, although that defeats the "split is safer" benefit) -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org