Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | [PATCH v2 2/10] cpufreq: governor: Use common mutex for dbs_data protection | Date | Fri, 05 Feb 2016 03:14:16 +0100 |
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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> --- drivers/cpufreq/cpufreq_conservative.c | 1 - drivers/cpufreq/cpufreq_governor.c | 7 +++++-- drivers/cpufreq/cpufreq_governor.h | 6 +----- drivers/cpufreq/cpufreq_ondemand.c | 5 ++--- 4 files changed, 8 insertions(+), 11 deletions(-)
Index: linux-pm/drivers/cpufreq/cpufreq_governor.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c +++ linux-pm/drivers/cpufreq/cpufreq_governor.c @@ -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()) @@ -541,7 +544,7 @@ int cpufreq_governor_dbs(struct cpufreq_ 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; @@ -574,7 +577,7 @@ int cpufreq_governor_dbs(struct cpufreq_ } unlock: - mutex_unlock(&cdata->mutex); + mutex_unlock(&dbs_data_mutex); return ret; } Index: linux-pm/drivers/cpufreq/cpufreq_governor.h =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_governor.h +++ linux-pm/drivers/cpufreq/cpufreq_governor.h @@ -225,11 +225,6 @@ 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 */ @@ -274,6 +269,7 @@ static ssize_t show_sampling_rate_min_go return sprintf(buf, "%u\n", dbs_data->min_sampling_rate); \ } +extern struct mutex dbs_data_mutex; extern struct mutex cpufreq_governor_lock; void gov_set_update_util(struct cpu_common_dbs_info *shared, unsigned int delay_us); Index: linux-pm/drivers/cpufreq/cpufreq_ondemand.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_ondemand.c +++ linux-pm/drivers/cpufreq/cpufreq_ondemand.c @@ -249,7 +249,7 @@ static void update_sampling_rate(struct /* * 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); @@ -302,7 +302,7 @@ static void update_sampling_rate(struct } } - 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, @@ -548,7 +548,6 @@ static struct common_dbs_data od_dbs_cda .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, Index: linux-pm/drivers/cpufreq/cpufreq_conservative.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_conservative.c +++ linux-pm/drivers/cpufreq/cpufreq_conservative.c @@ -368,7 +368,6 @@ static struct common_dbs_data cs_dbs_cda .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,
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