From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760316AbYCUS6y (ORCPT ); Fri, 21 Mar 2008 14:58:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754392AbYCUS6q (ORCPT ); Fri, 21 Mar 2008 14:58:46 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:43046 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753433AbYCUS6p (ORCPT ); Fri, 21 Mar 2008 14:58:45 -0400 Date: Fri, 21 Mar 2008 19:58:21 +0100 From: Ingo Molnar To: Ravikiran G Thirumalai Cc: Yinghai Lu , Andrew Morton , linux-kernel@vger.kernel.org, Glauber de Oliveira Costa , shai@scalex86.org Subject: Re: [patch 4/4] x86: apic_is_clustered_box to indicate unsynched TSC's on multiboard vSMP systems Message-ID: <20080321185821.GE6571@elte.hu> References: <20080320073740.GA9414@localdomain> <20080320074508.GE9414@localdomain> <86802c440803200053m1b0928a9q6567d8c619fa7a2f@mail.gmail.com> <20080320190240.GB6085@localdomain> <20080321091542.GE20420@elte.hu> <20080321185225.GA23139@localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080321185225.GA23139@localdomain> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0001] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ravikiran G Thirumalai wrote: > As for the observation about probing the pci space early during the > bootup, we call vsmp_init() much earlier during the bootup, which > calls is_vsmp_box(), does the pci probing and caches the result in the > flag, as you suggest. So the call in the above diff context does not > access the pci config space as is. ah, i see - indeed - the trick with -1 :-) my point remains though: if you initialize VSMP in a separate function anyway then please move this PCI config space access from is_vsmp_box() into vsmp_init() and keep a pure flag return is_vsmp_box(). That way there can be no question at all whether there are (or can be) any side-effects of that function. Ingo