Commit 0bb065f2 authored by Dave Jones's avatar Dave Jones
parents 329b10bb 7c9d8c0e
...@@ -35,12 +35,7 @@ ...@@ -35,12 +35,7 @@
*/ */
#define DEF_FREQUENCY_UP_THRESHOLD (80) #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 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 * The polling frequency of this governor depends on the capability of
...@@ -53,10 +48,14 @@ ...@@ -53,10 +48,14 @@
* All times here are in uS. * All times here are in uS.
*/ */
static unsigned int def_sampling_rate; 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 MAX_SAMPLING_RATE (500 * def_sampling_rate)
#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (100000) #define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000)
#define DEF_SAMPLING_DOWN_FACTOR (5) #define DEF_SAMPLING_DOWN_FACTOR (1)
#define MAX_SAMPLING_DOWN_FACTOR (10)
#define TRANSITION_LATENCY_LIMIT (10 * 1000) #define TRANSITION_LATENCY_LIMIT (10 * 1000)
static void do_dbs_timer(void *data); static void do_dbs_timer(void *data);
...@@ -66,6 +65,8 @@ struct cpu_dbs_info_s { ...@@ -66,6 +65,8 @@ struct cpu_dbs_info_s {
unsigned int prev_cpu_idle_up; unsigned int prev_cpu_idle_up;
unsigned int prev_cpu_idle_down; unsigned int prev_cpu_idle_down;
unsigned int enable; unsigned int enable;
unsigned int down_skip;
unsigned int requested_freq;
}; };
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
...@@ -136,7 +137,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, ...@@ -136,7 +137,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
unsigned int input; unsigned int input;
int ret; int ret;
ret = sscanf (buf, "%u", &input); ret = sscanf (buf, "%u", &input);
if (ret != 1 ) if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
return -EINVAL; return -EINVAL;
mutex_lock(&dbs_mutex); mutex_lock(&dbs_mutex);
...@@ -173,8 +174,7 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused, ...@@ -173,8 +174,7 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused,
ret = sscanf (buf, "%u", &input); ret = sscanf (buf, "%u", &input);
mutex_lock(&dbs_mutex); mutex_lock(&dbs_mutex);
if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || if (ret != 1 || input > 100 || input < 0 ||
input < MIN_FREQUENCY_UP_THRESHOLD ||
input <= dbs_tuners_ins.down_threshold) { input <= dbs_tuners_ins.down_threshold) {
mutex_unlock(&dbs_mutex); mutex_unlock(&dbs_mutex);
return -EINVAL; return -EINVAL;
...@@ -194,8 +194,7 @@ static ssize_t store_down_threshold(struct cpufreq_policy *unused, ...@@ -194,8 +194,7 @@ static ssize_t store_down_threshold(struct cpufreq_policy *unused,
ret = sscanf (buf, "%u", &input); ret = sscanf (buf, "%u", &input);
mutex_lock(&dbs_mutex); mutex_lock(&dbs_mutex);
if (ret != 1 || input > MAX_FREQUENCY_DOWN_THRESHOLD || if (ret != 1 || input > 100 || input < 0 ||
input < MIN_FREQUENCY_DOWN_THRESHOLD ||
input >= dbs_tuners_ins.up_threshold) { input >= dbs_tuners_ins.up_threshold) {
mutex_unlock(&dbs_mutex); mutex_unlock(&dbs_mutex);
return -EINVAL; return -EINVAL;
...@@ -297,31 +296,17 @@ static struct attribute_group dbs_attr_group = { ...@@ -297,31 +296,17 @@ static struct attribute_group dbs_attr_group = {
static void dbs_check_cpu(int cpu) static void dbs_check_cpu(int cpu)
{ {
unsigned int idle_ticks, up_idle_ticks, down_idle_ticks; unsigned int idle_ticks, up_idle_ticks, down_idle_ticks;
unsigned int tmp_idle_ticks, total_idle_ticks;
unsigned int freq_step; unsigned int freq_step;
unsigned int freq_down_sampling_rate; unsigned int freq_down_sampling_rate;
static int down_skip[NR_CPUS]; struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
static int requested_freq[NR_CPUS];
static unsigned short init_flag = 0;
struct cpu_dbs_info_s *this_dbs_info;
struct cpu_dbs_info_s *dbs_info;
struct cpufreq_policy *policy; struct cpufreq_policy *policy;
unsigned int j;
this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
if (!this_dbs_info->enable) if (!this_dbs_info->enable)
return; return;
policy = this_dbs_info->cur_policy; policy = this_dbs_info->cur_policy;
if ( init_flag == 0 ) {
for_each_online_cpu(j) {
dbs_info = &per_cpu(cpu_dbs_info, j);
requested_freq[j] = dbs_info->cur_policy->cur;
}
init_flag = 1;
}
/* /*
* The default safe range is 20% to 80% * The default safe range is 20% to 80%
* Every sampling_rate, we check * Every sampling_rate, we check
...@@ -337,22 +322,16 @@ static void dbs_check_cpu(int cpu) ...@@ -337,22 +322,16 @@ static void dbs_check_cpu(int cpu)
*/ */
/* Check for frequency increase */ /* Check for frequency increase */
idle_ticks = UINT_MAX; idle_ticks = UINT_MAX;
for_each_cpu_mask(j, policy->cpus) {
unsigned int tmp_idle_ticks, total_idle_ticks;
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
/* Check for frequency increase */ /* Check for frequency increase */
total_idle_ticks = get_cpu_idle_time(j); total_idle_ticks = get_cpu_idle_time(cpu);
tmp_idle_ticks = total_idle_ticks - tmp_idle_ticks = total_idle_ticks -
j_dbs_info->prev_cpu_idle_up; this_dbs_info->prev_cpu_idle_up;
j_dbs_info->prev_cpu_idle_up = total_idle_ticks; this_dbs_info->prev_cpu_idle_up = total_idle_ticks;
if (tmp_idle_ticks < idle_ticks) if (tmp_idle_ticks < idle_ticks)
idle_ticks = tmp_idle_ticks; idle_ticks = tmp_idle_ticks;
}
/* Scale idle ticks by 100 and compare with up and down ticks */ /* Scale idle ticks by 100 and compare with up and down ticks */
idle_ticks *= 100; idle_ticks *= 100;
...@@ -360,16 +339,12 @@ static void dbs_check_cpu(int cpu) ...@@ -360,16 +339,12 @@ static void dbs_check_cpu(int cpu)
usecs_to_jiffies(dbs_tuners_ins.sampling_rate); usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
if (idle_ticks < up_idle_ticks) { if (idle_ticks < up_idle_ticks) {
down_skip[cpu] = 0; this_dbs_info->down_skip = 0;
for_each_cpu_mask(j, policy->cpus) { this_dbs_info->prev_cpu_idle_down =
struct cpu_dbs_info_s *j_dbs_info; this_dbs_info->prev_cpu_idle_up;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
j_dbs_info->prev_cpu_idle_down =
j_dbs_info->prev_cpu_idle_up;
}
/* if we are already at full speed then break out early */ /* if we are already at full speed then break out early */
if (requested_freq[cpu] == policy->max) if (this_dbs_info->requested_freq == policy->max)
return; return;
freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100; freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100;
...@@ -378,38 +353,32 @@ static void dbs_check_cpu(int cpu) ...@@ -378,38 +353,32 @@ static void dbs_check_cpu(int cpu)
if (unlikely(freq_step == 0)) if (unlikely(freq_step == 0))
freq_step = 5; freq_step = 5;
requested_freq[cpu] += freq_step; this_dbs_info->requested_freq += freq_step;
if (requested_freq[cpu] > policy->max) if (this_dbs_info->requested_freq > policy->max)
requested_freq[cpu] = policy->max; this_dbs_info->requested_freq = policy->max;
__cpufreq_driver_target(policy, requested_freq[cpu], __cpufreq_driver_target(policy, this_dbs_info->requested_freq,
CPUFREQ_RELATION_H); CPUFREQ_RELATION_H);
return; return;
} }
/* Check for frequency decrease */ /* Check for frequency decrease */
down_skip[cpu]++; this_dbs_info->down_skip++;
if (down_skip[cpu] < dbs_tuners_ins.sampling_down_factor) if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor)
return; return;
idle_ticks = UINT_MAX; /* Check for frequency decrease */
for_each_cpu_mask(j, policy->cpus) { total_idle_ticks = this_dbs_info->prev_cpu_idle_up;
unsigned int tmp_idle_ticks, total_idle_ticks;
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
total_idle_ticks = j_dbs_info->prev_cpu_idle_up;
tmp_idle_ticks = total_idle_ticks - tmp_idle_ticks = total_idle_ticks -
j_dbs_info->prev_cpu_idle_down; this_dbs_info->prev_cpu_idle_down;
j_dbs_info->prev_cpu_idle_down = total_idle_ticks; this_dbs_info->prev_cpu_idle_down = total_idle_ticks;
if (tmp_idle_ticks < idle_ticks) if (tmp_idle_ticks < idle_ticks)
idle_ticks = tmp_idle_ticks; idle_ticks = tmp_idle_ticks;
}
/* Scale idle ticks by 100 and compare with up and down ticks */ /* Scale idle ticks by 100 and compare with up and down ticks */
idle_ticks *= 100; idle_ticks *= 100;
down_skip[cpu] = 0; this_dbs_info->down_skip = 0;
freq_down_sampling_rate = dbs_tuners_ins.sampling_rate * freq_down_sampling_rate = dbs_tuners_ins.sampling_rate *
dbs_tuners_ins.sampling_down_factor; dbs_tuners_ins.sampling_down_factor;
...@@ -417,10 +386,12 @@ static void dbs_check_cpu(int cpu) ...@@ -417,10 +386,12 @@ static void dbs_check_cpu(int cpu)
usecs_to_jiffies(freq_down_sampling_rate); usecs_to_jiffies(freq_down_sampling_rate);
if (idle_ticks > down_idle_ticks) { 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 * 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 */
if (this_dbs_info->requested_freq == policy->min
|| dbs_tuners_ins.freq_step == 0) || dbs_tuners_ins.freq_step == 0)
return; return;
...@@ -430,12 +401,11 @@ static void dbs_check_cpu(int cpu) ...@@ -430,12 +401,11 @@ static void dbs_check_cpu(int cpu)
if (unlikely(freq_step == 0)) if (unlikely(freq_step == 0))
freq_step = 5; freq_step = 5;
requested_freq[cpu] -= freq_step; this_dbs_info->requested_freq -= freq_step;
if (requested_freq[cpu] < policy->min) if (this_dbs_info->requested_freq < policy->min)
requested_freq[cpu] = policy->min; this_dbs_info->requested_freq = policy->min;
__cpufreq_driver_target(policy, __cpufreq_driver_target(policy, this_dbs_info->requested_freq,
requested_freq[cpu],
CPUFREQ_RELATION_H); CPUFREQ_RELATION_H);
return; return;
} }
...@@ -493,11 +463,13 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, ...@@ -493,11 +463,13 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
j_dbs_info = &per_cpu(cpu_dbs_info, j); j_dbs_info = &per_cpu(cpu_dbs_info, j);
j_dbs_info->cur_policy = policy; j_dbs_info->cur_policy = policy;
j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j); j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(cpu);
j_dbs_info->prev_cpu_idle_down j_dbs_info->prev_cpu_idle_down
= j_dbs_info->prev_cpu_idle_up; = j_dbs_info->prev_cpu_idle_up;
} }
this_dbs_info->enable = 1; this_dbs_info->enable = 1;
this_dbs_info->down_skip = 0;
this_dbs_info->requested_freq = policy->cur;
sysfs_create_group(&policy->kobj, &dbs_attr_group); sysfs_create_group(&policy->kobj, &dbs_attr_group);
dbs_enable++; dbs_enable++;
/* /*
...@@ -507,13 +479,16 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, ...@@ -507,13 +479,16 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
if (dbs_enable == 1) { if (dbs_enable == 1) {
unsigned int latency; unsigned int latency;
/* policy latency is in nS. Convert it to uS first */ /* 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; def_sampling_rate = 10 * latency *
if (latency < 1000)
latency = 1000;
def_sampling_rate = (latency / 1000) *
DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; 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.sampling_rate = def_sampling_rate;
dbs_tuners_ins.ignore_nice = 0; dbs_tuners_ins.ignore_nice = 0;
dbs_tuners_ins.freq_step = 5; dbs_tuners_ins.freq_step = 5;
......
...@@ -84,6 +84,7 @@ struct dbs_tuners { ...@@ -84,6 +84,7 @@ struct dbs_tuners {
static struct dbs_tuners dbs_tuners_ins = { static struct dbs_tuners dbs_tuners_ins = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD, .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
.ignore_nice = 0,
}; };
static inline unsigned int get_cpu_idle_time(unsigned int cpu) static inline unsigned int get_cpu_idle_time(unsigned int cpu)
...@@ -350,6 +351,9 @@ static void dbs_check_cpu(int cpu) ...@@ -350,6 +351,9 @@ static void dbs_check_cpu(int cpu)
freq_next = (freq_next * policy->cur) / freq_next = (freq_next * policy->cur) /
(dbs_tuners_ins.up_threshold - 10); (dbs_tuners_ins.up_threshold - 10);
if (freq_next < policy->min)
freq_next = policy->min;
if (freq_next <= ((policy->cur * 95) / 100)) if (freq_next <= ((policy->cur * 95) / 100))
__cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_L); __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_L);
} }
...@@ -395,8 +399,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, ...@@ -395,8 +399,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
return -EINVAL; return -EINVAL;
if (policy->cpuinfo.transition_latency > if (policy->cpuinfo.transition_latency >
(TRANSITION_LATENCY_LIMIT * 1000)) (TRANSITION_LATENCY_LIMIT * 1000)) {
printk(KERN_WARNING "ondemand governor failed to load "
"due to too long transition latency\n");
return -EINVAL; return -EINVAL;
}
if (this_dbs_info->enable) /* Already enabled */ if (this_dbs_info->enable) /* Already enabled */
break; break;
...@@ -431,8 +438,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, ...@@ -431,8 +438,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
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.sampling_rate = def_sampling_rate;
dbs_tuners_ins.ignore_nice = 0;
dbs_timer_init(); dbs_timer_init();
} }
......
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