From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: [patch 06/20] cpufreq: Use cpuhp_setup_state_nocalls_locked() Date: Sat, 15 Apr 2017 19:01:13 +0200 Message-ID: <20170415171651.746595672@linutronix.de> References: <20170415170107.643253702@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Return-path: Received: from Galois.linutronix.de ([146.0.238.70]:44470 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754641AbdDORbO (ORCPT ); Sat, 15 Apr 2017 13:31:14 -0400 Content-Disposition: inline; filename=cpufreq-Use-cpuhp_setup_state_nocalls_locked.patch Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: LKML Cc: Peter Zijlstra , Ingo Molnar , Steven Rostedt , Sebastian Siewior , "Rafael J. Wysocki" , Viresh Kumar , linux-pm@vger.kernel.org From: Sebastian Andrzej Siewior cpufreq holds get_online_cpus() while invoking cpuhp_setup_state_nocalls() to make subsys_interface_register() and the registration of hotplug calls atomic versus cpu hotplug. cpuhp_setup_state_nocalls() invokes get_online_cpus() as well. This is correct, but prevents the conversion of the hotplug locking to a percpu rwsem. Use cpuhp_setup_state_nocalls_locked() to avoid the nested call. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: "Rafael J. Wysocki" Cc: Viresh Kumar Cc: linux-pm@vger.kernel.org --- drivers/cpufreq/cpufreq.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2473,9 +2473,10 @@ int cpufreq_register_driver(struct cpufr goto err_if_unreg; } - ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "cpufreq:online", - cpuhp_cpufreq_online, - cpuhp_cpufreq_offline); + ret = cpuhp_setup_state_nocalls_locked(CPUHP_AP_ONLINE_DYN, + "cpufreq:online", + cpuhp_cpufreq_online, + cpuhp_cpufreq_offline); if (ret < 0) goto err_if_unreg; hp_online = ret; @@ -2519,7 +2520,7 @@ int cpufreq_unregister_driver(struct cpu get_online_cpus(); subsys_interface_unregister(&cpufreq_interface); remove_boost_sysfs_file(); - cpuhp_remove_state_nocalls(hp_online); + cpuhp_remove_state_nocalls_locked(hp_online); write_lock_irqsave(&cpufreq_driver_lock, flags);