cpufreq: interactive governor: go to intermediate hi speed before max

* Add attribute hispeed_freq, which defaults to max.

* Rename go_maxspeed_load to go_hispeed_load.

* If hit go_hispeed_load and at min speed, go to hispeed_freq;
  if hit go_hispeed_load and already above min speed go to max
  speed.

Change-Id: I1050dec5f013fc1177387352ba787a7e1c68703e
Signed-off-by: Todd Poynor <toddpoynor@google.com>

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 72ae653..859fdc1 100644 (file)
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -58,9 +58,12 @@ static cpumask_t down_cpumask;
 static spinlock_t down_cpumask_lock;
 static struct mutex set_speed_lock;
 
-/* Go to max speed when CPU load at or above this value. */
-#define DEFAULT_GO_MAXSPEED_LOAD 95
-static unsigned long go_maxspeed_load;
+/* Hi speed to bump to from lo speed when load burst (default max) */
+static u64 hispeed_freq;
+
+/* Go to hi speed when CPU load at or above this value. */
+#define DEFAULT_GO_HISPEED_LOAD 95
+static unsigned long go_hispeed_load;
 
 /*
  * The minimum amount of time to spend at a frequency before we can ramp down.
@@ -159,9 +162,9 @@ static void cpufreq_interactive_timer(unsigned long data)
        if (load_since_change > cpu_load)
                cpu_load = load_since_change;
 
-       if (cpu_load >= go_maxspeed_load) {
+       if (cpu_load >= go_hispeed_load) {
                if (pcpu->policy->cur == pcpu->policy->min)
-                       new_freq = pcpu->policy->max;
+                       new_freq = hispeed_freq;
                else
                        new_freq = pcpu->policy->max * cpu_load / 100;
        } else {
@@ -427,13 +430,37 @@ static void cpufreq_interactive_freq_down(struct work_struct *work)
        }
 }
 
-static ssize_t show_go_maxspeed_load(struct kobject *kobj,
+static ssize_t show_hispeed_freq(struct kobject *kobj,
+                                struct attribute *attr, char *buf)
+{
+       return sprintf(buf, "%llu\n", hispeed_freq);
+}
+
+static ssize_t store_hispeed_freq(struct kobject *kobj,
+                                 struct attribute *attr, const char *buf,
+                                 size_t count)
+{
+       int ret;
+       u64 val;
+
+       ret = strict_strtoull(buf, 0, &val);
+       if (ret < 0)
+               return ret;
+       hispeed_freq = val;
+       return count;
+}
+
+static struct global_attr hispeed_freq_attr = __ATTR(hispeed_freq, 0644,
+               show_hispeed_freq, store_hispeed_freq);
+
+
+static ssize_t show_go_hispeed_load(struct kobject *kobj,
                                     struct attribute *attr, char *buf)
 {
-       return sprintf(buf, "%lu\n", go_maxspeed_load);
+       return sprintf(buf, "%lu\n", go_hispeed_load);
 }
 
-static ssize_t store_go_maxspeed_load(struct kobject *kobj,
+static ssize_t store_go_hispeed_load(struct kobject *kobj,
                        struct attribute *attr, const char *buf, size_t count)
 {
        int ret;
@@ -442,12 +469,12 @@ static ssize_t store_go_maxspeed_load(struct kobject *kobj,
        ret = strict_strtoul(buf, 0, &val);
        if (ret < 0)
                return ret;
-       go_maxspeed_load = val;
+       go_hispeed_load = val;
        return count;
 }
 
-static struct global_attr go_maxspeed_load_attr = __ATTR(go_maxspeed_load, 0644,
-               show_go_maxspeed_load, store_go_maxspeed_load);
+static struct global_attr go_hispeed_load_attr = __ATTR(go_hispeed_load, 0644,
+               show_go_hispeed_load, store_go_hispeed_load);
 
 static ssize_t show_min_sample_time(struct kobject *kobj,
                                struct attribute *attr, char *buf)
@@ -494,7 +521,8 @@ 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,
+       &hispeed_freq_attr.attr,
+       &go_hispeed_load_attr.attr,
        &min_sample_time_attr.attr,
        &timer_rate_attr.attr,
        NULL,
@@ -533,6 +561,9 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
                        smp_wmb();
                }
 
+               if (!hispeed_freq)
+                       hispeed_freq = policy->max;
+
                /*
                 * Do not register the idle hook and create sysfs
                 * entries if we have already done so.
@@ -610,7 +641,7 @@ static int __init cpufreq_interactive_init(void)
        struct cpufreq_interactive_cpuinfo *pcpu;
        struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
 
-       go_maxspeed_load = DEFAULT_GO_MAXSPEED_LOAD;
+       go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
        min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
        timer_rate = DEFAULT_TIMER_RATE;