From patchwork Tue Nov 13 19:32:43 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 1737541 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 6D4453FCAE for ; Wed, 14 Nov 2012 02:38:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932459Ab2KNCh4 (ORCPT ); Tue, 13 Nov 2012 21:37:56 -0500 Received: from mga14.intel.com ([143.182.124.37]:3412 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932423Ab2KNCdn (ORCPT ); Tue, 13 Nov 2012 21:33:43 -0500 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga102.ch.intel.com with ESMTP; 13 Nov 2012 18:33:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.83,247,1352102400"; d="scan'208";a="217413928" Received: from fenghua-desk.sc.intel.com ([10.3.52.80]) by azsmga001.ch.intel.com with ESMTP; 13 Nov 2012 18:33:42 -0800 From: "Fenghua Yu" To: "Ingo Molnar" , "Thomas Gleixner" , "H Peter Anvin" , "Linus Torvalds" , "Andrew Morton" , "Asit K Mallick" , "Tony Luck" , "Arjan Dan De Ven" , "Suresh B Siddha" , "Len Brown" , "Srivatssa S. Bhat" , "Randy Dunlap" , "Rafael J. Wysocki" , "Chen Gong" , "linux-kernel" , "linux-pm" , "x86" Cc: "Fenghua Yu" Subject: [PATCH v10 06/14] kernel/cpu.c: Add comment for priority in cpu_hotplug_pm_callback Date: Tue, 13 Nov 2012 11:32:43 -0800 Message-Id: <1352835171-3958-7-git-send-email-fenghua.yu@intel.com> X-Mailer: git-send-email 1.7.2 In-Reply-To: <1352835171-3958-1-git-send-email-fenghua.yu@intel.com> References: <1352835171-3958-1-git-send-email-fenghua.yu@intel.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Fenghua Yu cpu_hotplug_pm_callback should have higher priority than bsp_pm_callback which depends on cpu_hotplug_pm_callback to disable cpu hotplug to avoid race during bsp online checking. This is to hightlight the priorities between the two callbacks in case people may overlook the order. Ideally the priorities should be defined in macro/enum instead of fixed values. To do that, a seperate patchset may be pushed which will touch serveral other generic files and is out of scope of this patchset. Signed-off-by: Fenghua Yu Reviewed-by: Srivatsa S. Bhat Acked-by: Rafael J. Wysocki --- kernel/cpu.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/kernel/cpu.c b/kernel/cpu.c index 42bd331..a2491a2 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -601,6 +601,11 @@ cpu_hotplug_pm_callback(struct notifier_block *nb, static int __init cpu_hotplug_pm_sync_init(void) { + /* + * cpu_hotplug_pm_callback has higher priority than x86 + * bsp_pm_callback which depends on cpu_hotplug_pm_callback + * to disable cpu hotplug to avoid cpu hotplug race. + */ pm_notifier(cpu_hotplug_pm_callback, 0); return 0; }