From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754502Ab2EHM0Z (ORCPT ); Tue, 8 May 2012 08:26:25 -0400 Received: from terminus.zytor.com ([198.137.202.10]:54661 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754106Ab2EHM0Y (ORCPT ); Tue, 8 May 2012 08:26:24 -0400 Date: Tue, 8 May 2012 05:26:08 -0700 From: tip-bot for Thomas Gleixner Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de In-Reply-To: <20120507175652.049316594@linutronix.de> References: <20120507175652.049316594@linutronix.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:smp/hotplug] smp: Implement kick_all_cpus_sync() Git-Commit-ID: f37f435f33717dcf15fd4bb422da739da7fc2052 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Tue, 08 May 2012 05:26:13 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f37f435f33717dcf15fd4bb422da739da7fc2052 Gitweb: http://git.kernel.org/tip/f37f435f33717dcf15fd4bb422da739da7fc2052 Author: Thomas Gleixner AuthorDate: Mon, 7 May 2012 17:59:48 +0000 Committer: Thomas Gleixner CommitDate: Tue, 8 May 2012 12:35:06 +0200 smp: Implement kick_all_cpus_sync() Will replace the misnomed cpu_idle_wait() function which is copied a gazillion times all over arch/* Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20120507175652.049316594@linutronix.de --- include/linux/smp.h | 4 ++++ kernel/smp.c | 23 +++++++++++++++++++++++ 2 files changed, 27 insertions(+), 0 deletions(-) diff --git a/include/linux/smp.h b/include/linux/smp.h index 24360de..717fb74 100644 --- a/include/linux/smp.h +++ b/include/linux/smp.h @@ -81,6 +81,8 @@ void __smp_call_function_single(int cpuid, struct call_single_data *data, int smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, void *info, int wait); +void kick_all_cpus_sync(void); + /* * Generic and arch helpers */ @@ -192,6 +194,8 @@ smp_call_function_any(const struct cpumask *mask, smp_call_func_t func, return smp_call_function_single(0, func, info, wait); } +static inline void kick_all_cpus_sync(void) { } + #endif /* !SMP */ /* diff --git a/kernel/smp.c b/kernel/smp.c index a61294c..d0ae5b2 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -795,3 +795,26 @@ 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 + * + * Used to synchronize the update of pm_idle function pointer. It's + * called after the pointer is updated and returns after the dummy + * callback function has been executed on all cpus. The execution of + * the function can only happen on the remote cpus after they have + * left the idle function which had been called via pm_idle function + * pointer. So it's guaranteed that nothing uses the previous pointer + * anymore. + */ +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); +} +EXPORT_SYMBOL_GPL(kick_all_cpus_sync);