On Thursday, October 29, 2015 08:08:38 AM Viresh Kumar wrote: > gov_queue_work() acquires cpufreq_governor_lock to allow > cpufreq_governor_stop() to drain delayed work items possibly scheduled > on CPUs that share the policy with a CPU being taken offline. > > However, the same goal may be achieved in a more straightforward way if > the policy pointer in the struct cpu_dbs_info matching the policy CPU is > reset upfront by cpufreq_governor_stop() under the timer_mutex belonging > to it and checked against NULL, under the same lock, at the beginning of > dbs_timer(). > > In that case every instance of dbs_timer() run for a struct cpu_dbs_info > sharing the policy pointer in question after cpufreq_governor_stop() has > started will notice that that pointer is NULL and bail out immediately > without queuing up any new work items. In turn, gov_cancel_work() > called by cpufreq_governor_stop() before destroying timer_mutex will > wait for all of the delayed work items currently running on the CPUs > sharing the policy to drop the mutex, so it may be destroyed safely. > > Make cpufreq_governor_stop() and dbs_timer() work as described and > modify gov_queue_work() so it does not acquire cpufreq_governor_lock any > more. > > Signed-off-by: Viresh Kumar <viresh.ku...@linaro.org>
Applied, thanks! Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
