From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759514AbYBZDp5 (ORCPT ); Mon, 25 Feb 2008 22:45:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754567AbYBZDpu (ORCPT ); Mon, 25 Feb 2008 22:45:50 -0500 Received: from one.firstfloor.org ([213.235.205.2]:45444 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754547AbYBZDpt (ORCPT ); Mon, 25 Feb 2008 22:45:49 -0500 Date: Tue, 26 Feb 2008 04:46:25 +0100 From: Andi Kleen To: Ravikiran Thirumalai Cc: Yinghai Lu , Andi Kleen , Ingo Molnar , Andrew Morton , Linux Kernel Mailing List , shai@scalemp.com Subject: Re: [PATCH] x86_64: make amd quad core 8 socket system not be clustered_box v2 Message-ID: <20080226034625.GE21577@one.firstfloor.org> References: <200802210258.45011.yinghai.lu@sun.com> <200802221102.31019.yinghai.lu@sun.com> <47BF1BD9.4020808@firstfloor.org> <200802232148.43255.yinghai.lu@sun.com> <20080224122903.GC13637@one.firstfloor.org> <20080225190819.GE3143@localdomain> <86802c440802251405w7025a8b2na5fde4dcbf56067e@mail.gmail.com> <20080226033945.GJ3143@localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080226033945.GJ3143@localdomain> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I don't quite understand the purpose of the patch to begin with. Looking at > the current x86 git tree, apic_is_clustered_box is used only to determine if > tsc is synchronized on the platform. The AMD docs imply that TSC's are not > guaranteed to be synced across cores between nodes -- Opteron BKDG for > family 10h, Section 2.9.4: After long discussions with AMD they determined the CPUID flag for sync RDTSC will imply synchronization between nodes. If you can't support that in your hardware you're supposed to clear it. -Andi