From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753955AbYE1TBI (ORCPT ); Wed, 28 May 2008 15:01:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752230AbYE1TA6 (ORCPT ); Wed, 28 May 2008 15:00:58 -0400 Received: from fg-out-1718.google.com ([72.14.220.155]:19665 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752505AbYE1TA5 (ORCPT ); Wed, 28 May 2008 15:00:57 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type:content-disposition:user-agent; b=b6onsVHU8PRoIUuoL/+jKSIEN7MzgToZcb5TiN/1m1XcPBPbvlTuItlfzQEC9TRiYPilJDI1QMXVKgXM2Eg0w6BKuQOEaEAVbRMv7M2uofGgf3rZUkEu1x3Vd2s6uTyqVBdiy+dfALPW2wlLfvw3FnvnCDUJvvpgnOLuKQbt9yI= Date: Wed, 28 May 2008 23:00:47 +0400 From: Cyrill Gorcunov To: "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner Cc: "Maciej W. Rozycki" , Sitsofe Wheeler , Adrian Bunk , LKML Subject: [PATCH] x86: nmi - fix incorrect NMI watchdog used by default Message-ID: <20080528190047.GE6910@cvg> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The commit commit 4b82b277707a39b97271439c475f186f63ec4692 Author: Cyrill Gorcunov Date: Sat May 24 19:36:35 2008 +0400 set nmi_watchdog to NMI_IO_APIC as by default. This causes hangs on some machines with buggy watchdogs. Fix it - i.e. restore old behaviour. Thanks to Sitsofe Wheeler and Adrian Bunk for catching the problem and Maciej W. Rozycki for explanation what is going on there. Signed-off-by: Cyrill Gorcunov CC: Maciej W. Rozycki --- The patch is over today tip/x86/nmi Index: linux-2.6.git/arch/x86/kernel/nmi.c ==================================================================== --- linux-2.6.git.orig/arch/x86/kernel/nmi.c 2008-05-28 22:32:38.000000000 +0400 +++ linux-2.6.git/arch/x86/kernel/nmi.c 2008-05-28 22:40:48.000000000 +0400 @@ -84,20 +84,15 @@ static inline unsigned int get_timer_irq #endif } +#ifdef CONFIG_X86_64 /* Run after command line and cpu_init init, but before all other checks */ void nmi_watchdog_default(void) { if (nmi_watchdog != NMI_DEFAULT) return; -#ifdef CONFIG_X86_64 nmi_watchdog = NMI_NONE; -#else - if (lapic_watchdog_ok()) - nmi_watchdog = NMI_LOCAL_APIC; - else - nmi_watchdog = NMI_IO_APIC; -#endif } +#endif #ifdef CONFIG_SMP /* @@ -488,8 +483,15 @@ int proc_nmi_enabled(struct ctl_table *t return -EIO; } +#ifdef CONFIG_X86_64 /* if nmi_watchdog is not set yet, then set it */ nmi_watchdog_default(); +#else + if (lapic_watchdog_ok()) + nmi_watchdog = NMI_LOCAL_APIC; + else + nmi_watchdog = NMI_IO_APIC; +#endif if (nmi_watchdog == NMI_LOCAL_APIC) { if (nmi_watchdog_enabled) Index: linux-2.6.git/include/asm-x86/nmi.h ==================================================================== --- linux-2.6.git.orig/include/asm-x86/nmi.h 2008-05-28 22:32:41.000000000 +0400 +++ linux-2.6.git/include/asm-x86/nmi.h 2008-05-28 22:39:55.000000000 +0400 @@ -38,9 +38,11 @@ static inline void unset_nmi_pm_callback #ifdef CONFIG_X86_64 extern void default_do_nmi(struct pt_regs *); +extern void nmi_watchdog_default(void); +#else +#define nmi_watchdog_default(void) do {} while (0) #endif -extern void nmi_watchdog_default(void); extern void die_nmi(char *str, struct pt_regs *regs, int do_panic); extern int check_nmi_watchdog(void); extern int nmi_watchdog_enabled;