[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: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 6dc8380..0565916 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -79,6 +79,7 @@
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(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 @@
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(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 @@
&up_threshold.attr,
&down_threshold.attr,
&ignore_nice.attr,
+ &freq_step.attr,
NULL
};
@@ -291,7 +318,7 @@
*
* 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 @@
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 @@
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();
}