Commit b394058f authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

cpufreq: governors: Reset tunables only for cpufreq_unregister_governor() 



Currently, whenever governor->governor() is called for CPUFRREQ_GOV_START event
we reset few tunables of governor. Which isn't correct, as this routine is
called for every cpu hot-[un]plugging event. We should actually be resetting
these only when the governor module is removed and re-installed.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 4447266b

drivers/cpufreq/cpufreq.c

+4 −0
Original line number Diff line number Diff line
@@ -1562,6 +1562,9 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, 
						policy->cpu, event);

	ret = policy->governor->governor(policy, event);



	if (!policy->governor->initialized && (event == CPUFREQ_GOV_START))

		policy->governor->initialized = 1;



	/* we keep one module reference alive for

			each CPU governed by this CPU */

	if ((event != CPUFREQ_GOV_START) || ret)
@@ -1585,6 +1588,7 @@ int cpufreq_register_governor(struct cpufreq_governor *governor) 


	mutex_lock(&cpufreq_governor_mutex);



	governor->initialized = 0;

	err = -EBUSY;

	if (__find_governor(governor->name) == NULL) {

		err = 0;

drivers/cpufreq/cpufreq_governor.c

+16 −8
Original line number Diff line number Diff line
@@ -254,11 +254,6 @@ int cpufreq_governor_dbs(struct dbs_data *dbs_data, 
			return rc;

		}



		/* policy latency is in nS. Convert it to uS first */

		latency = policy->cpuinfo.transition_latency / 1000;

		if (latency == 0)

			latency = 1;



		/*

		 * conservative does not implement micro like ondemand

		 * governor, thus we are bound to jiffes/HZ
@@ -270,20 +265,33 @@ int cpufreq_governor_dbs(struct dbs_data *dbs_data, 
			cpufreq_register_notifier(cs_ops->notifier_block,

					CPUFREQ_TRANSITION_NOTIFIER);



			dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *

			if (!policy->governor->initialized)

				dbs_data->min_sampling_rate =

					MIN_SAMPLING_RATE_RATIO *

					jiffies_to_usecs(10);

		} else {

			od_dbs_info->rate_mult = 1;

			od_dbs_info->sample_type = OD_NORMAL_SAMPLE;

			od_ops->powersave_bias_init_cpu(cpu);



			if (!policy->governor->initialized)

				od_tuners->io_is_busy = od_ops->io_busy();

		}



		if (policy->governor->initialized)

			goto unlock;



		/* policy latency is in nS. Convert it to uS first */

		latency = policy->cpuinfo.transition_latency / 1000;

		if (latency == 0)

			latency = 1;



		/* Bring kernel and HW constraints together */

		dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,

				MIN_LATENCY_MULTIPLIER * latency);

		*sampling_rate = max(dbs_data->min_sampling_rate, latency *

				LATENCY_MULTIPLIER);

unlock:

		mutex_unlock(&dbs_data->mutex);



		/* Initiate timer time stamp */

include/linux/cpufreq.h

+1 −0
Original line number Diff line number Diff line
@@ -183,6 +183,7 @@ static inline unsigned long cpufreq_scale(unsigned long old, u_int div, u_int mu 


struct cpufreq_governor {

	char	name[CPUFREQ_NAME_LEN];

	int	initialized;

	int	(*governor)	(struct cpufreq_policy *policy,

				 unsigned int event);

	ssize_t	(*show_setspeed)	(struct cpufreq_policy *policy,

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