diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
-rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.c | 43 |
1 files changed, 23 insertions, 20 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 929e193ac1c1..da7f3514d948 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -189,7 +189,7 @@ static void od_check_cpu(int cpu, unsigned int load) } } -static unsigned int od_dbs_timer(struct cpufreq_policy *policy, bool modify_all) +static unsigned int od_dbs_timer(struct cpufreq_policy *policy) { struct dbs_data *dbs_data = policy->governor_data; unsigned int cpu = policy->cpu; @@ -198,9 +198,6 @@ static unsigned int od_dbs_timer(struct cpufreq_policy *policy, bool modify_all) struct od_dbs_tuners *od_tuners = dbs_data->tuners; int delay = 0, sample_type = dbs_info->sample_type; - if (!modify_all) - goto max_delay; - /* Common NORMAL_SAMPLE setup */ dbs_info->sample_type = OD_NORMAL_SAMPLE; if (sample_type == OD_SUB_SAMPLE) { @@ -216,7 +213,6 @@ static unsigned int od_dbs_timer(struct cpufreq_policy *policy, bool modify_all) } } -max_delay: if (!delay) delay = delay_for_sampling_rate(od_tuners->sampling_rate * dbs_info->rate_mult); @@ -262,7 +258,6 @@ static void update_sampling_rate(struct dbs_data *dbs_data, struct od_cpu_dbs_info_s *dbs_info; struct cpu_dbs_info *cdbs; struct cpu_common_dbs_info *shared; - unsigned long next_sampling, appointed_at; dbs_info = &per_cpu(od_cpu_dbs_info, cpu); cdbs = &dbs_info->cdbs; @@ -286,20 +281,28 @@ static void update_sampling_rate(struct dbs_data *dbs_data, * policy will be governed by dbs_data, otherwise there can be * multiple policies that are governed by the same dbs_data. */ - if (dbs_data != policy->governor_data) - continue; - - /* - * Checking this for any CPU should be fine, timers for all of - * them are scheduled together. - */ - next_sampling = jiffies + usecs_to_jiffies(new_rate); - appointed_at = dbs_info->cdbs.timer.expires; - - if (time_before(next_sampling, appointed_at)) { - gov_cancel_work(shared); - gov_add_timers(policy, usecs_to_jiffies(new_rate)); - + if (dbs_data == policy->governor_data) { + mutex_lock(&shared->timer_mutex); + /* + * On 32-bit architectures this may race with the + * sample_delay_ns read in dbs_update_util_handler(), + * but that really doesn't matter. If the read returns + * a value that's too big, the sample will be skipped, + * but the next invocation of dbs_update_util_handler() + * (when the update has been completed) will take a + * sample. If the returned value is too small, the + * sample will be taken immediately, but that isn't a + * problem, as we want the new rate to take effect + * immediately anyway. + * + * If this runs in parallel with dbs_work_handler(), we + * may end up overwriting the sample_delay_ns value that + * it has just written, but the difference should not be + * too big and it will be corrected next time a sample + * is taken, so it shouldn't be significant. + */ + gov_update_sample_delay(shared, new_rate); + mutex_unlock(&shared->timer_mutex); } } |