From patchwork Fri Aug 15 07:01:24 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuansheng Liu X-Patchwork-Id: 4726361 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 943F69FADA for ; Fri, 15 Aug 2014 07:19:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id C9874201E4 for ; Fri, 15 Aug 2014 07:19:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA7E1201DD for ; Fri, 15 Aug 2014 07:19:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752245AbaHOHTU (ORCPT ); Fri, 15 Aug 2014 03:19:20 -0400 Received: from mga03.intel.com ([143.182.124.21]:36866 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751182AbaHOHTT (ORCPT ); Fri, 15 Aug 2014 03:19:19 -0400 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga101.ch.intel.com with ESMTP; 15 Aug 2014 00:19:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,868,1400050800"; d="scan'208";a="469012697" Received: from shsibuild003.sh.intel.com ([10.239.146.212]) by azsmga001.ch.intel.com with ESMTP; 15 Aug 2014 00:19:15 -0700 From: Chuansheng Liu To: peterz@infradead.org, luto@amacapital.net, daniel.lezcano@linaro.org, rjw@rjwysocki.net, mingo@redhat.com Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, changcheng.liu@intel.com, xiaoming.wang@intel.com, souvik.k.chakravarty@intel.com, Chuansheng Liu Subject: [PATCH 2/3] smp: re-implement the kick_all_cpus_sync() with wake_up_if_idle() Date: Fri, 15 Aug 2014 15:01:24 +0800 Message-Id: <1408086085-16691-2-git-send-email-chuansheng.liu@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1408086085-16691-1-git-send-email-chuansheng.liu@intel.com> References: <1408086085-16691-1-git-send-email-chuansheng.liu@intel.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently using smp_call_function() just woke up the corresponding cpu, but can not break the polling idle loop. Here using the new sched API wake_up_if_idle() to implement it. Signed-off-by: Chuansheng Liu --- kernel/smp.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/kernel/smp.c b/kernel/smp.c index aff8aa1..0b647c3 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -13,6 +13,7 @@ #include #include #include +#include #include "smpboot.h" @@ -677,10 +678,6 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info), } EXPORT_SYMBOL(on_each_cpu_cond); -static void do_nothing(void *unused) -{ -} - /** * kick_all_cpus_sync - Force all cpus out of idle * @@ -694,8 +691,15 @@ static void do_nothing(void *unused) */ void kick_all_cpus_sync(void) { - /* Make sure the change is visible before we kick the cpus */ - smp_mb(); - smp_call_function(do_nothing, NULL, 1); + int cpu; + + preempt_disable(); + for_each_online_cpu(cpu) { + if (cpu == smp_processor_id()) + continue; + + wake_up_if_idle(cpu); + } + preempt_enable(); } EXPORT_SYMBOL_GPL(kick_all_cpus_sync);