| Date | Thu, 20 Apr 2017 04:21:25 -0700 | From | tip-bot for Sebastian Andrzej Siewior <> | Subject | [tip:smp/hotplug] cpufreq: Use cpuhp_setup_state_nocalls_cpuslocked() |
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Commit-ID: 6d7d2f1f9e6e0c2d6fb9de82ad5fbc3aed115829 Gitweb: http://git.kernel.org/tip/6d7d2f1f9e6e0c2d6fb9de82ad5fbc3aed115829 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> AuthorDate: Tue, 18 Apr 2017 19:04:48 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Thu, 20 Apr 2017 13:08:52 +0200
cpufreq: Use cpuhp_setup_state_nocalls_cpuslocked()
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/remove_state_nocalls_cpuslocked() to avoid the nested call.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linux-pm@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170418170552.865966021@linutronix.de
--- drivers/cpufreq/cpufreq.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 0e3f649..67ef7ce 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2473,9 +2473,10 @@ int cpufreq_register_driver(struct cpufreq_driver *driver_data) 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_cpuslocked(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 cpufreq_driver *driver) get_online_cpus(); subsys_interface_unregister(&cpufreq_interface); remove_boost_sysfs_file(); - cpuhp_remove_state_nocalls(hp_online); + cpuhp_remove_state_nocalls_cpuslocked(hp_online); write_lock_irqsave(&cpufreq_driver_lock, flags);
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