From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754009AbYGVSFa (ORCPT ); Tue, 22 Jul 2008 14:05:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752074AbYGVSFT (ORCPT ); Tue, 22 Jul 2008 14:05:19 -0400 Received: from rv-out-0506.google.com ([209.85.198.235]:3877 "EHLO rv-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752119AbYGVSFS (ORCPT ); Tue, 22 Jul 2008 14:05:18 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=AhT5PLCReNuivPNBTasQtCAiyb1vmMhxHCp1NH6sqBXMr/1kGJArSxK/hrA6w6/p9k NGgf9R79IVHmevu49YSvV5y/7WVyrdwX238MmWWUczq0wqCoBPEWAFKAGAByJ7FdeYzq 9daHjBWuYG8rOn1nnz7TbdBrfwxglW6PKv7iU= Message-ID: <86802c440807221105s77372df8re2e59440a8f644bd@mail.gmail.com> Date: Tue, 22 Jul 2008 11:05:17 -0700 From: "Yinghai Lu" To: "Suresh Siddha" Subject: Re: [PATCH] x86: add apic probe for genapic 64bit v2 Cc: "Ingo Molnar" , "Thomas Gleixner" , "H. Peter Anvin" , "Jack Steiner" , "linux-kernel@vger.kernel.org" In-Reply-To: <20080722175757.GC14380@linux-os.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200807211836.27282.yhlu.kernel@gmail.com> <200807212208.22116.yhlu.kernel@gmail.com> <20080722175757.GC14380@linux-os.sc.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 22, 2008 at 10:57 AM, Suresh Siddha wrote: > On Mon, Jul 21, 2008 at 10:08:21PM -0700, Yinghai Lu wrote: >> >> Index: linux-2.6/arch/x86/kernel/genapic_64.c >> =================================================================== >> --- linux-2.6.orig/arch/x86/kernel/genapic_64.c >> +++ linux-2.6/arch/x86/kernel/genapic_64.c >> - genapic = &apic_x2apic_cluster; > ... > >> - } else >> -#ifdef CONFIG_ACPI >> - /* >> - * Quirk: some x86_64 machines can only use physical APIC mode >> - * regardless of how many processors are present (x86_64 ES7000 >> - * is an example). >> - */ >> - if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID && >> - (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL)) >> - genapic = &apic_physflat; >> - else >> -#endif >> - >> - if (max_physical_apicid < 8) >> - genapic = &apic_flat; >> - else >> - genapic = &apic_physflat; >> - >> - printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name); >> + if (genapic == &apic_flat) { >> + if (max_physical_apicid >= 8) > > Yinghai, though not directly realted to this probe cleanup, what is this > 'max_physical_apicid' doing. > > I don't understand the need for this commit. > >> commit e0da33646826b66ef933d47ea2fb7a693fd849bf >> Author: Yinghai Lu >> Date: Sun Jun 8 18:29:22 2008 -0700 >> >> x86: introduce max_physical_apicid for bigsmp switching >> >> a multi-socket test-system with 3 or 4 ioapics, when 4 dualcore cpus or >> 2 quadcore cpus installed, needs to switch to bigsmp or physflat. >> >> CPU apic id is [4,11] instead of [0,7], and we need to check max apic >> id instead of cpu numbers. > > for logical flat, it really shouldn't matter how large the physical apic id > is. In logical flat, OS programs the LDR and the limitation is the > number of cpu's which is '8'. before i clean up 32bit, 64bit already used max_physical_apicid to check if need to switch to physflat. for 32bit, if not switch to bigsmp, cpu with physical apic id >=8 can not be started by BSP. YH