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cpufreq: governor: Use common mutex for dbs_data protection 

Every governor relying on the common code in cpufreq_governor.c
has to provide its own mutex in struct common_dbs_data.  However,
there actually is no need to have a separate mutex per governor
for this purpose, they may be using the same global mutex just
fine.  Accordingly, introduce a single common mutex for that and
drop the mutex field from struct common_dbs_data.

That at least will ensure that the mutex is always present and
initialized regardless of what the particular governors do.

Another benefit is that the common code does not need a pointer to
a governor-related structure to get to the mutex which sometimes
helps.

Finally, it makes the code generally easier to follow.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Saravana Kannan <skannan@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Rafael J. Wysocki 2016-02-07 16:01:31 +01:00
parent 9be4fd2c77
commit 2bb8d94fb0
4 changed files with 8 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/cpufreq/cpufreq_conservative.c
View File

@ -368,7 +368,6 @@ static struct common_dbs_data cs_dbs_cdata = {
.gov_check_cpu = cs_check_cpu,
.init = cs_init,
.exit = cs_exit,
.mutex = __MUTEX_INITIALIZER(cs_dbs_cdata.mutex),
};
static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,

7
drivers/cpufreq/cpufreq_governor.c
View File

@ -22,6 +22,9 @@
#include "cpufreq_governor.h"
DEFINE_MUTEX(dbs_data_mutex);
EXPORT_SYMBOL_GPL(dbs_data_mutex);
static struct attribute_group *get_sysfs_attr(struct dbs_data *dbs_data)
{
if (have_governor_per_policy())
@ -543,7 +546,7 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy,
int ret;
/* Lock governor to block concurrent initialization of governor */
mutex_lock(&cdata->mutex);
mutex_lock(&dbs_data_mutex);
if (have_governor_per_policy())
dbs_data = policy->governor_data;
@ -576,7 +579,7 @@ int cpufreq_governor_dbs(struct cpufreq_policy *policy,
}
unlock:
mutex_unlock(&cdata->mutex);
mutex_unlock(&dbs_data_mutex);
return ret;
}

6
drivers/cpufreq/cpufreq_governor.h
View File

@ -228,11 +228,6 @@ struct common_dbs_data {
/* Governor specific ops, see below */
void *gov_ops;
/*
* Protects governor's data (struct dbs_data and struct common_dbs_data)
*/
struct mutex mutex;
};
/* Governor Per policy data */
@ -277,6 +272,7 @@ static ssize_t show_sampling_rate_min_gov_pol \
return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \
}
extern struct mutex dbs_data_mutex;
extern struct mutex cpufreq_governor_lock;
void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
int cpufreq_governor_dbs(struct cpufreq_policy *policy,

5
drivers/cpufreq/cpufreq_ondemand.c
View File

@ -249,7 +249,7 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
/*
* Lock governor so that governor start/stop can't execute in parallel.
*/
mutex_lock(&od_dbs_cdata.mutex);
mutex_lock(&dbs_data_mutex);
cpumask_copy(&cpumask, cpu_online_mask);
@ -306,7 +306,7 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
}
}
mutex_unlock(&od_dbs_cdata.mutex);
mutex_unlock(&dbs_data_mutex);
}
static ssize_t store_sampling_rate(struct dbs_data *dbs_data, const char *buf,
@ -552,7 +552,6 @@ static struct common_dbs_data od_dbs_cdata = {
.gov_ops = &od_ops,
.init = od_init,
.exit = od_exit,
.mutex = __MUTEX_INITIALIZER(od_dbs_cdata.mutex),
};
static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy,