cpufreq: interactive: add sysfs control for timer rate
Add a new sysfs control that tunes the rate of the timer used to
increase cpu frequency
Change-Id: I1aa13ae54bb43aff5b3688984d2955f56aae1658
Signed-off-by: Allen Martin <amartin@nvidia.com>
diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index fe20e31..6a98631d 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -66,6 +66,12 @@
#define DEFAULT_MIN_SAMPLE_TIME 80000;
static unsigned long min_sample_time;
+/*
+ * The sample rate of the timer used to increase frequency
+ */
+#define DEFAULT_TIMER_RATE 30000;
+static unsigned long timer_rate;
+
static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
unsigned int event);
@@ -219,7 +225,7 @@
pcpu->time_in_idle = get_cpu_idle_time_us(
data, &pcpu->idle_exit_time);
- mod_timer(&pcpu->cpu_timer, jiffies + 2);
+ mod_timer(&pcpu->cpu_timer, jiffies + usecs_to_jiffies(timer_rate));
}
exit:
@@ -254,7 +260,7 @@
pcpu->time_in_idle = get_cpu_idle_time_us(
smp_processor_id(), &pcpu->idle_exit_time);
pcpu->timer_idlecancel = 0;
- mod_timer(&pcpu->cpu_timer, jiffies + 2);
+ mod_timer(&pcpu->cpu_timer, jiffies + usecs_to_jiffies(timer_rate));
}
#endif
} else {
@@ -304,7 +310,7 @@
get_cpu_idle_time_us(smp_processor_id(),
&pcpu->idle_exit_time);
pcpu->timer_idlecancel = 0;
- mod_timer(&pcpu->cpu_timer, jiffies + 2);
+ mod_timer(&pcpu->cpu_timer, jiffies + usecs_to_jiffies(timer_rate));
}
}
@@ -429,9 +435,32 @@
static struct global_attr min_sample_time_attr = __ATTR(min_sample_time, 0644,
show_min_sample_time, store_min_sample_time);
+static ssize_t show_timer_rate(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ return sprintf(buf, "%lu\n", timer_rate);
+}
+
+static ssize_t store_timer_rate(struct kobject *kobj,
+ struct attribute *attr, const char *buf, size_t count)
+{
+ int ret;
+ unsigned long val;
+
+ ret = strict_strtoul(buf, 0, &val);
+ if (ret < 0)
+ return ret;
+ timer_rate = val;
+ return count;
+}
+
+static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
+ show_timer_rate, store_timer_rate);
+
static struct attribute *interactive_attributes[] = {
&go_maxspeed_load_attr.attr,
&min_sample_time_attr.attr,
+ &timer_rate_attr.attr,
NULL,
};
@@ -547,6 +576,7 @@
go_maxspeed_load = DEFAULT_GO_MAXSPEED_LOAD;
min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
+ timer_rate = DEFAULT_TIMER_RATE;
/* Initalize per-cpu timers */
for_each_possible_cpu(i) {