From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932319Ab3DCThq (ORCPT ); Wed, 3 Apr 2013 15:37:46 -0400 Received: from relay3.sgi.com ([192.48.152.1]:51227 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759815Ab3DCThp (ORCPT ); Wed, 3 Apr 2013 15:37:45 -0400 Date: Wed, 3 Apr 2013 14:37:43 -0500 From: Robin Holt To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Russ Anderson , Shawn Guo , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org Subject: [PATCH] Do not force shutdown/reboot to boot cpu. Message-ID: <20130403193743.GB29151@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We noticed that recently, reboot of a 1024 cpu machine takes approx 16 minutes of just stopping the cpus. The slowdown was tracked to commit f96972f which went into v3.7 and then to the stable trees. x86 does not need to be running the boot cpu to pull reset and I don't think it is really needed for shutdown either. I decided to go the "simple" way and make this a config option that is selected by the x86 arch. I don't know which other arch's would also benefit, if any. Signed-off-by: Robin Holt To: Andrew Morton Cc: Russ Anderson Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Shawn Guo Cc: --- arch/x86/Kconfig | 3 +++ kernel/Kconfig.shutdown | 3 +++ kernel/sys.c | 4 ++++ 3 files changed, 10 insertions(+) create mode 100644 kernel/Kconfig.shutdown diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 70c0f3d..9611942 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -120,6 +120,7 @@ config X86 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION select OLD_SIGACTION if X86_32 select COMPAT_OLD_SIGACTION if IA32_EMULATION + select ARCH_SHUTDOWN_TO_ANY_CPU config INSTRUCTION_DECODER def_bool y @@ -839,6 +840,8 @@ config SCHED_MC making when dealing with multi-core CPU chips at a cost of slightly increased overhead in some places. If unsure say N here. +source "kernel/Kconfig.shutdown" + source "kernel/Kconfig.preempt" config X86_UP_APIC diff --git a/kernel/Kconfig.shutdown b/kernel/Kconfig.shutdown new file mode 100644 index 0000000..d79fc04 --- /dev/null +++ b/kernel/Kconfig.shutdown @@ -0,0 +1,3 @@ + +config ARCH_SHUTDOWN_TO_ANY_CPU + bool diff --git a/kernel/sys.c b/kernel/sys.c index 39c9c4a..c0b8880 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -369,7 +369,9 @@ EXPORT_SYMBOL(unregister_reboot_notifier); void kernel_restart(char *cmd) { kernel_restart_prepare(cmd); +#ifndef CONFIG_ARCH_SHUTDOWN_TO_ANY_CPU disable_nonboot_cpus(); +#endif if (!cmd) printk(KERN_EMERG "Restarting system.\n"); else @@ -413,7 +415,9 @@ void kernel_power_off(void) kernel_shutdown_prepare(SYSTEM_POWER_OFF); if (pm_power_off_prepare) pm_power_off_prepare(); +#ifndef CONFIG_ARCH_SHUTDOWN_TO_ANY_CPU disable_nonboot_cpus(); +#endif syscore_shutdown(); printk(KERN_EMERG "Power down.\n"); kmsg_dump(KMSG_DUMP_POWEROFF); -- 1.8.1.2