summaryrefslogtreecommitdiff
path: root/drivers/cpufreq/cpufreq_ondemand.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
-rw-r--r--drivers/cpufreq/cpufreq_ondemand.c50
1 files changed, 23 insertions, 27 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index e741c339df76..a235114c3d85 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -32,6 +32,7 @@
#define DEF_FREQUENCY_UP_THRESHOLD (80)
#define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3)
#define MICRO_FREQUENCY_UP_THRESHOLD (95)
+#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000)
#define MIN_FREQUENCY_UP_THRESHOLD (11)
#define MAX_FREQUENCY_UP_THRESHOLD (100)
@@ -45,27 +46,12 @@
* this governor will not work.
* All times here are in uS.
*/
-static unsigned int def_sampling_rate;
#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)
-/* Above MIN_SAMPLING_RATE will vanish with its sysfs file soon
- * Define the minimal settable sampling rate to the greater of:
- * - "HW transition latency" * 100 (same as default sampling / 10)
- * - MIN_STAT_SAMPLING_RATE
- * To avoid that userspace shoots itself.
-*/
-static unsigned int minimum_sampling_rate(void)
-{
- return max(def_sampling_rate / 10, MIN_STAT_SAMPLING_RATE);
-}
-/* This will also vanish soon with removing sampling_rate_max */
-#define MAX_SAMPLING_RATE (500 * def_sampling_rate)
+static unsigned int min_sampling_rate;
+
#define LATENCY_MULTIPLIER (1000)
+#define MIN_LATENCY_MULTIPLIER (100)
#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
static void do_dbs_timer(struct work_struct *work);
@@ -227,7 +213,7 @@ static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
current->comm);
print_once = 1;
}
- return sprintf(buf, "%u\n", MAX_SAMPLING_RATE);
+ return sprintf(buf, "%u\n", -1U);
}
static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
@@ -240,7 +226,7 @@ static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
current->comm);
print_once = 1;
}
- return sprintf(buf, "%u\n", MIN_SAMPLING_RATE);
+ return sprintf(buf, "%u\n", min_sampling_rate);
}
#define define_one_ro(_name) \
@@ -274,7 +260,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
mutex_unlock(&dbs_mutex);
return -EINVAL;
}
- dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate());
+ dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
mutex_unlock(&dbs_mutex);
return count;
@@ -619,12 +605,12 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
latency = policy->cpuinfo.transition_latency / 1000;
if (latency == 0)
latency = 1;
-
- def_sampling_rate =
- max(latency * LATENCY_MULTIPLIER,
- MIN_STAT_SAMPLING_RATE);
-
- dbs_tuners_ins.sampling_rate = def_sampling_rate;
+ /* Bring kernel and HW constraints together */
+ min_sampling_rate = max(min_sampling_rate,
+ MIN_LATENCY_MULTIPLIER * latency);
+ dbs_tuners_ins.sampling_rate =
+ max(min_sampling_rate,
+ latency * LATENCY_MULTIPLIER);
}
dbs_timer_init(this_dbs_info);
@@ -678,6 +664,16 @@ static int __init cpufreq_gov_dbs_init(void)
dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
dbs_tuners_ins.down_differential =
MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
+ /*
+ * In no_hz/micro accounting case we set the minimum frequency
+ * not depending on HZ, but fixed (very low). The deferred
+ * timer might skip some samples if idle/sleeping as needed.
+ */
+ min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE;
+ } else {
+ /* For correct statistics, we need 10 ticks for each measure */
+ min_sampling_rate =
+ MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10);
}
kondemand_wq = create_workqueue("kondemand");