From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936106AbWK1UZZ (ORCPT ); Tue, 28 Nov 2006 15:25:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936104AbWK1UZZ (ORCPT ); Tue, 28 Nov 2006 15:25:25 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:14735 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S936099AbWK1UZY (ORCPT ); Tue, 28 Nov 2006 15:25:24 -0500 Date: Tue, 28 Nov 2006 21:23:22 +0100 From: Ingo Molnar To: "Siddha, Suresh B" Cc: mm-commits@vger.kernel.org, ak@suse.de, ashok.raj@intel.com, akpm@osdl.org, linux-kernel@vger.kernel.org Subject: [patch] genapic: default to physical mode on hotplug CPU kernels Message-ID: <20061128202322.GA29334@elte.hu> References: <200611140109.kAE19f5e014490@shell0.pdx.osdl.net> <20061127141849.A9978@unix-os.sc.intel.com> <20061128063345.GA19523@elte.hu> <20061128111414.A16460@unix-os.sc.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061128111414.A16460@unix-os.sc.intel.com> User-Agent: Mutt/1.4.2.2i X-ELTE-SpamScore: -4.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-4.5 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] 1.4 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Siddha, Suresh B wrote: > On Tue, Nov 28, 2006 at 07:33:46AM +0100, Ingo Molnar wrote: > > - if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster) > > + if (max_apic < 8) > > Patch mostly looks good. Instead of checking for max_apic, can we use > cpus_weight(cpu_possible_map) <= 8 ok - but i think it's still possible the BIOS tells us APIC IDs that are larger than 7, even if there are fewer CPUs. So i think the patch below should cover it. Agreed? Ingo --------------------> From: Ingo Molnar Subject: [patch] genapic: default to physical mode on hotplug CPU kernels default to physical mode on hotplug CPU kernels. Signed-off-by: Ingo Molnar Index: linux/arch/x86_64/kernel/genapic.c =================================================================== --- linux.orig/arch/x86_64/kernel/genapic.c +++ linux/arch/x86_64/kernel/genapic.c @@ -51,7 +51,7 @@ void __init clustered_apic_check(void) max_apic = id; } - if (max_apic < 8) + if (max_apic < 8 && cpus_weight(cpu_possible_map) <= 8) genapic = &apic_flat; else genapic = &apic_physflat;