From: Rafael J. Wysocki <[email protected]> The conservative governor registers a transition notifier so it can update its internal requested_freq value if it falls out of the policy->min...policy->max range, but that's not the most straightforward way to achieve that.
To do it in a more straightforward way, first make sure that cs_dbs_timer() will only set frequencies between min and max. With that, note that requested_freq will always fall between min and max unless either policy->min or policy->max changes and the governor's ->limits() callback will be invoked then. Using this observation, add a ->limits callback pointer to struct dbs_governor, make cpufreq_dbs_governor_limits() invoke that callback if present, implement that callback in the conservative governor to update requested_freq if needed and drop the transition notifier from it, which also makes it possible to drop the struct cs_governor definition from there and simplify the code accordingly. Signed-off-by: Rafael J. Wysocki <[email protected]> --- drivers/cpufreq/cpufreq_conservative.c | 85 +++++++-------------------------- drivers/cpufreq/cpufreq_governor.c | 4 + drivers/cpufreq/cpufreq_governor.h | 1 3 files changed, 25 insertions(+), 65 deletions(-) Index: linux-pm/drivers/cpufreq/cpufreq_conservative.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_conservative.c +++ linux-pm/drivers/cpufreq/cpufreq_conservative.c @@ -106,7 +106,8 @@ static unsigned int cs_dbs_timer(struct goto out; freq_target = get_freq_target(cs_tuners, policy); - if (dbs_info->requested_freq > freq_target) + if (dbs_info->requested_freq > freq_target + && dbs_info->requested_freq - freq_target > policy->min) dbs_info->requested_freq -= freq_target; else dbs_info->requested_freq = policy->min; @@ -119,13 +120,6 @@ static unsigned int cs_dbs_timer(struct return dbs_data->sampling_rate; } -static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, - void *data); - -static struct notifier_block cs_cpufreq_notifier_block = { - .notifier_call = dbs_cpufreq_notifier, -}; - /************************** sysfs interface ************************/ static ssize_t store_sampling_down_factor(struct gov_attr_set *attr_set, @@ -254,13 +248,6 @@ static struct attribute *cs_attributes[] /************************** sysfs end ************************/ -struct cs_governor { - struct dbs_governor dbs_gov; - unsigned int usage_count; -}; - -static struct cs_governor cs_gov; - static struct policy_dbs_info *cs_alloc(void) { struct cs_policy_dbs_info *dbs_info; @@ -294,25 +281,11 @@ static int cs_init(struct dbs_data *dbs_ dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); - /* - * This function and cs_exit() are only called under gov_dbs_data_mutex - * which is global, so the cs_gov.usage_count accesses are guaranteed - * to be serialized. - */ - if (!cs_gov.usage_count++) - cpufreq_register_notifier(&cs_cpufreq_notifier_block, - CPUFREQ_TRANSITION_NOTIFIER); - return 0; } static void cs_exit(struct dbs_data *dbs_data) { - /* Protected by gov_dbs_data_mutex - see the comment in cs_init(). */ - if (!--cs_gov.usage_count) - cpufreq_unregister_notifier(&cs_cpufreq_notifier_block, - CPUFREQ_TRANSITION_NOTIFIER); - kfree(dbs_data->tuners); } @@ -324,47 +297,29 @@ static void cs_start(struct cpufreq_poli dbs_info->requested_freq = policy->cur; } -static struct cs_governor cs_gov = { - .dbs_gov = { - .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"), - .kobj_type = { .default_attrs = cs_attributes }, - .gov_dbs_timer = cs_dbs_timer, - .alloc = cs_alloc, - .free = cs_free, - .init = cs_init, - .exit = cs_exit, - .start = cs_start, - }, -}; - -#define CPU_FREQ_GOV_CONSERVATIVE (&cs_gov.dbs_gov.gov) - -static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, - void *data) +static void cs_limits(struct cpufreq_policy *policy) { - struct cpufreq_freqs *freq = data; - struct cpufreq_policy *policy = cpufreq_cpu_get_raw(freq->cpu); - struct cs_policy_dbs_info *dbs_info; - - if (!policy) - return 0; - - /* policy isn't governed by conservative governor */ - if (policy->governor != CPU_FREQ_GOV_CONSERVATIVE) - return 0; + struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data); - dbs_info = to_dbs_info(policy->governor_data); - /* - * we only care if our internally tracked freq moves outside the 'valid' - * ranges of frequency available to us otherwise we do not change it - */ if (dbs_info->requested_freq > policy->max - || dbs_info->requested_freq < policy->min) - dbs_info->requested_freq = freq->new; - - return 0; + || dbs_info->requested_freq < policy->min) + dbs_info->requested_freq = policy->cur; } +static struct dbs_governor cs_governor = { + .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"), + .kobj_type = { .default_attrs = cs_attributes }, + .gov_dbs_timer = cs_dbs_timer, + .alloc = cs_alloc, + .free = cs_free, + .init = cs_init, + .exit = cs_exit, + .start = cs_start, + .limits = cs_limits, +}; + +#define CPU_FREQ_GOV_CONSERVATIVE (&cs_governor.gov) + static int __init cpufreq_gov_dbs_init(void) { return cpufreq_register_governor(CPU_FREQ_GOV_CONSERVATIVE); Index: linux-pm/drivers/cpufreq/cpufreq_governor.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_governor.c +++ linux-pm/drivers/cpufreq/cpufreq_governor.c @@ -545,6 +545,7 @@ EXPORT_SYMBOL_GPL(cpufreq_dbs_governor_s void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy) { + struct dbs_governor *gov = dbs_governor_of(policy); struct policy_dbs_info *policy_dbs = policy->governor_data; mutex_lock(&policy_dbs->timer_mutex); @@ -554,6 +555,9 @@ void cpufreq_dbs_governor_limits(struct else if (policy->min > policy->cur) __cpufreq_driver_target(policy, policy->min, CPUFREQ_RELATION_L); + if (gov->limits) + gov->limits(policy); + gov_update_sample_delay(policy_dbs, 0); mutex_unlock(&policy_dbs->timer_mutex); Index: linux-pm/drivers/cpufreq/cpufreq_governor.h =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq_governor.h +++ linux-pm/drivers/cpufreq/cpufreq_governor.h @@ -141,6 +141,7 @@ struct dbs_governor { int (*init)(struct dbs_data *dbs_data); void (*exit)(struct dbs_data *dbs_data); void (*start)(struct cpufreq_policy *policy); + void (*limits)(struct cpufreq_policy *policy); }; static inline struct dbs_governor *dbs_governor_of(struct cpufreq_policy *policy)
