From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761170AbYEPWj5 (ORCPT ); Fri, 16 May 2008 18:39:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752277AbYEPWjq (ORCPT ); Fri, 16 May 2008 18:39:46 -0400 Received: from www.tglx.de ([62.245.132.106]:50022 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119AbYEPWjp (ORCPT ); Fri, 16 May 2008 18:39:45 -0400 Date: Sat, 17 May 2008 00:38:53 +0200 (CEST) From: Thomas Gleixner To: Linus Torvalds cc: LKML , Ingo Molnar , "H. Peter Anvin" Subject: [GIT pull] x86 fixes for 2.6.26 Message-ID: User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, please pull the latest x86 fixes from: ssh://master.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-fixes-for-linus Thanks, tglx ------------------> Avi Kivity (1): x86: fix crash on cpu hotplug on pat-incapable machines Ingo Molnar (1): x86: remove mwait capability C-state check Thomas Gleixner (1): x86: disable mwait for AMD family 10H/11H CPUs arch/x86/kernel/process.c | 36 +++++++++++++++++++++++++++--------- arch/x86/mm/pat.c | 2 +- 2 files changed, 28 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 67e9b4a..ba370dc 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -99,15 +99,6 @@ static void mwait_idle(void) local_irq_enable(); } - -static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) -{ - if (force_mwait) - return 1; - /* Any C1 states supported? */ - return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0; -} - /* * On SMP it's slightly faster (but much more power-consuming!) * to poll the ->work.need_resched flag instead of waiting for the @@ -119,6 +110,33 @@ static void poll_idle(void) cpu_relax(); } +/* + * mwait selection logic: + * + * It depends on the CPU. For AMD CPUs that support MWAIT this is + * wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings + * then depend on a clock divisor and current Pstate of the core. If + * all cores of a processor are in halt state (C1) the processor can + * enter the C1E (C1 enhanced) state. If mwait is used this will never + * happen. + * + * idle=mwait overrides this decision and forces the usage of mwait. + */ +static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c) +{ + if (force_mwait) + return 1; + + if (c->x86_vendor == X86_VENDOR_AMD) { + switch(c->x86) { + case 0x10: + case 0x11: + return 0; + } + } + return 1; +} + void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) { static int selected; diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index bcb1a8e..de3a998 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -28,7 +28,7 @@ #ifdef CONFIG_X86_PAT int __read_mostly pat_wc_enabled = 1; -void __init pat_disable(char *reason) +void __cpuinit pat_disable(char *reason) { pat_wc_enabled = 0; printk(KERN_INFO "%s\n", reason);