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cpufreq: governors: Reset tunables only for cpufreq_unregister_governor()

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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: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2013-02-01 05:42:58 +00:00 • committed by Rafael J. Wysocki
commit b394058f06
3 changed files with 21 additions and 8 deletions
Download patch file Download diff file Expand all files Collapse all files

4
drivers/cpufreq/cpufreq.c
View file

@ -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;

24
drivers/cpufreq/cpufreq_governor.c
View file

@ -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 *
jiffies_to_usecs(10);
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);
od_tuners->io_is_busy = od_ops->io_busy();
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 */

1
include/linux/cpufreq.h
View file

@ -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,