diff options
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/cpufreq_conservative.c | 53 |
1 files changed, 27 insertions, 26 deletions
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index ac38766b2583..adecd31f6156 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -35,12 +35,7 @@ */ #define DEF_FREQUENCY_UP_THRESHOLD (80) -#define MIN_FREQUENCY_UP_THRESHOLD (0) -#define MAX_FREQUENCY_UP_THRESHOLD (100) - #define DEF_FREQUENCY_DOWN_THRESHOLD (20) -#define MIN_FREQUENCY_DOWN_THRESHOLD (0) -#define MAX_FREQUENCY_DOWN_THRESHOLD (100) /* * The polling frequency of this governor depends on the capability of @@ -53,10 +48,14 @@ * All times here are in uS. */ static unsigned int def_sampling_rate; -#define MIN_SAMPLING_RATE (def_sampling_rate / 2) +#define MIN_SAMPLING_RATE_RATIO (2) +/* for correct statistics, we need at least 10 ticks between each measure */ +#define MIN_STAT_SAMPLING_RATE (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10)) +#define MIN_SAMPLING_RATE (def_sampling_rate / MIN_SAMPLING_RATE_RATIO) #define MAX_SAMPLING_RATE (500 * def_sampling_rate) -#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (100000) -#define DEF_SAMPLING_DOWN_FACTOR (5) +#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) +#define DEF_SAMPLING_DOWN_FACTOR (1) +#define MAX_SAMPLING_DOWN_FACTOR (10) #define TRANSITION_LATENCY_LIMIT (10 * 1000) static void do_dbs_timer(void *data); @@ -136,7 +135,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, unsigned int input; int ret; ret = sscanf (buf, "%u", &input); - if (ret != 1 ) + if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) return -EINVAL; mutex_lock(&dbs_mutex); @@ -173,8 +172,7 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused, ret = sscanf (buf, "%u", &input); mutex_lock(&dbs_mutex); - if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || - input < MIN_FREQUENCY_UP_THRESHOLD || + if (ret != 1 || input > 100 || input < 0 || input <= dbs_tuners_ins.down_threshold) { mutex_unlock(&dbs_mutex); return -EINVAL; @@ -194,8 +192,7 @@ static ssize_t store_down_threshold(struct cpufreq_policy *unused, ret = sscanf (buf, "%u", &input); mutex_lock(&dbs_mutex); - if (ret != 1 || input > MAX_FREQUENCY_DOWN_THRESHOLD || - input < MIN_FREQUENCY_DOWN_THRESHOLD || + if (ret != 1 || input > 100 || input < 0 || input >= dbs_tuners_ins.up_threshold) { mutex_unlock(&dbs_mutex); return -EINVAL; @@ -337,7 +334,6 @@ static void dbs_check_cpu(int cpu) */ /* Check for frequency increase */ - idle_ticks = UINT_MAX; for_each_cpu_mask(j, policy->cpus) { unsigned int tmp_idle_ticks, total_idle_ticks; @@ -357,7 +353,7 @@ static void dbs_check_cpu(int cpu) /* Scale idle ticks by 100 and compare with up and down ticks */ idle_ticks *= 100; up_idle_ticks = (100 - dbs_tuners_ins.up_threshold) * - usecs_to_jiffies(dbs_tuners_ins.sampling_rate); + usecs_to_jiffies(dbs_tuners_ins.sampling_rate); if (idle_ticks < up_idle_ticks) { down_skip[cpu] = 0; @@ -398,6 +394,7 @@ static void dbs_check_cpu(int cpu) struct cpu_dbs_info_s *j_dbs_info; j_dbs_info = &per_cpu(cpu_dbs_info, j); + /* Check for frequency decrease */ total_idle_ticks = j_dbs_info->prev_cpu_idle_up; tmp_idle_ticks = total_idle_ticks - j_dbs_info->prev_cpu_idle_down; @@ -414,12 +411,14 @@ static void dbs_check_cpu(int cpu) freq_down_sampling_rate = dbs_tuners_ins.sampling_rate * dbs_tuners_ins.sampling_down_factor; down_idle_ticks = (100 - dbs_tuners_ins.down_threshold) * - usecs_to_jiffies(freq_down_sampling_rate); + usecs_to_jiffies(freq_down_sampling_rate); if (idle_ticks > down_idle_ticks) { - /* if we are already at the lowest speed then break out early + /* + * if we are already at the lowest speed then break out early * or if we 'cannot' reduce the speed as the user might want - * freq_step to be zero */ + * freq_step to be zero + */ if (requested_freq[cpu] == policy->min || dbs_tuners_ins.freq_step == 0) return; @@ -434,9 +433,8 @@ static void dbs_check_cpu(int cpu) if (requested_freq[cpu] < policy->min) requested_freq[cpu] = policy->min; - __cpufreq_driver_target(policy, - requested_freq[cpu], - CPUFREQ_RELATION_H); + __cpufreq_driver_target(policy, requested_freq[cpu], + CPUFREQ_RELATION_H); return; } } @@ -507,13 +505,16 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, if (dbs_enable == 1) { unsigned int latency; /* policy latency is in nS. Convert it to uS first */ + latency = policy->cpuinfo.transition_latency / 1000; + if (latency == 0) + latency = 1; - latency = policy->cpuinfo.transition_latency; - if (latency < 1000) - latency = 1000; - - def_sampling_rate = (latency / 1000) * + def_sampling_rate = latency * DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; + + if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) + def_sampling_rate = MIN_STAT_SAMPLING_RATE; + dbs_tuners_ins.sampling_rate = def_sampling_rate; dbs_tuners_ins.ignore_nice = 0; dbs_tuners_ins.freq_step = 5; |