Commit 1206aaac authored by Dave Jones's avatar Dave Jones

[CPUFREQ] Allow ondemand stepping to be changed by user.

Adds support so that the cpufreq change stepping is no longer fixed at 5% and
can be changed dynamically by the user
Signed-off-by: default avatarAlexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: default avatarDave Jones <davej@redhat.com>
parent c11420a6
......@@ -79,6 +79,7 @@ struct dbs_tuners {
unsigned int up_threshold;
unsigned int down_threshold;
unsigned int ignore_nice;
unsigned int freq_step;
};
static struct dbs_tuners dbs_tuners_ins = {
......@@ -117,6 +118,7 @@ show_one(sampling_down_factor, sampling_down_factor);
show_one(up_threshold, up_threshold);
show_one(down_threshold, down_threshold);
show_one(ignore_nice, ignore_nice);
show_one(freq_step, freq_step);
static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
const char *buf, size_t count)
......@@ -235,6 +237,29 @@ static ssize_t store_ignore_nice(struct cpufreq_policy *policy,
return count;
}
static ssize_t store_freq_step(struct cpufreq_policy *policy,
const char *buf, size_t count)
{
unsigned int input;
int ret;
ret = sscanf (buf, "%u", &input);
if ( ret != 1 )
return -EINVAL;
if ( input > 100 )
input = 100;
/* no need to test here if freq_step is zero as the user might actually
* want this, they would be crazy though :) */
down(&dbs_sem);
dbs_tuners_ins.freq_step = input;
up(&dbs_sem);
return count;
}
#define define_one_rw(_name) \
static struct freq_attr _name = \
__ATTR(_name, 0644, show_##_name, store_##_name)
......@@ -244,6 +269,7 @@ define_one_rw(sampling_down_factor);
define_one_rw(up_threshold);
define_one_rw(down_threshold);
define_one_rw(ignore_nice);
define_one_rw(freq_step);
static struct attribute * dbs_attributes[] = {
&sampling_rate_max.attr,
......@@ -253,6 +279,7 @@ static struct attribute * dbs_attributes[] = {
&up_threshold.attr,
&down_threshold.attr,
&ignore_nice.attr,
&freq_step.attr,
NULL
};
......@@ -291,7 +318,7 @@ static void dbs_check_cpu(int cpu)
*
* Any frequency increase takes it to the maximum frequency.
* Frequency reduction happens at minimum steps of
* 5% of max_frequency
* 5% (default) of max_frequency
*/
/* Check for frequency increase */
......@@ -390,18 +417,20 @@ static void dbs_check_cpu(int cpu)
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 (policy->cur == policy->min)
/* 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 */
if (policy->cur == policy->min || dbs_tuners_ins.freq_step == 0)
return;
freq_down_step = (5 * policy->max) / 100;
freq_down_step = (dbs_tuners_ins.freq_step * policy->max) / 100;
/* max freq cannot be less than 100. But who knows.... */
if (unlikely(freq_down_step == 0))
freq_down_step = 5;
__cpufreq_driver_target(policy,
policy->cur - freq_down_step,
policy->cur - freq_down_step,
CPUFREQ_RELATION_H);
return;
}
......@@ -486,6 +515,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
DEF_SAMPLING_RATE_LATENCY_MULTIPLIER;
dbs_tuners_ins.sampling_rate = def_sampling_rate;
dbs_tuners_ins.ignore_nice = 0;
dbs_tuners_ins.freq_step = 5;
dbs_timer_init();
}
......
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