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Commit 083701b1 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: ondemand: Drop unnecessary locks from update_sampling_rate() 



'timer_mutex' is required to sync work-handlers of policy->cpus.
update_sampling_rate() is just canceling the works and queuing them
again. This isn't protecting anything at all in update_sampling_rate()
and is not gonna be of any use.

Even if a work-handler is already running for a CPU,
cancel_delayed_work_sync() will wait for it to finish.

Drop these unnecessary locks.

Reviewed-by: default avatarPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 51443fbf

drivers/cpufreq/cpufreq_ondemand.c

+1 −9
Original line number Diff line number Diff line
@@ -267,27 +267,19 @@ static void update_sampling_rate(struct dbs_data *dbs_data, 
		dbs_info = &per_cpu(od_cpu_dbs_info, cpu);

		cpufreq_cpu_put(policy);



		mutex_lock(&dbs_info->cdbs.shared->timer_mutex);



		if (!delayed_work_pending(&dbs_info->cdbs.dwork)) {

			mutex_unlock(&dbs_info->cdbs.shared->timer_mutex);

		if (!delayed_work_pending(&dbs_info->cdbs.dwork))

			continue;

		}



		next_sampling = jiffies + usecs_to_jiffies(new_rate);

		appointed_at = dbs_info->cdbs.dwork.timer.expires;



		if (time_before(next_sampling, appointed_at)) {



			mutex_unlock(&dbs_info->cdbs.shared->timer_mutex);

			cancel_delayed_work_sync(&dbs_info->cdbs.dwork);

			mutex_lock(&dbs_info->cdbs.shared->timer_mutex);



			gov_queue_work(dbs_data, policy,

				       usecs_to_jiffies(new_rate), true);



		}

		mutex_unlock(&dbs_info->cdbs.shared->timer_mutex);

	}

}