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path: root/drivers/cpufreq/cpufreq_ondemand.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
-rw-r--r--drivers/cpufreq/cpufreq_ondemand.c42
1 files changed, 41 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 7b5093664e4..c631f27a3dc 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -30,6 +30,8 @@
#define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10)
#define DEF_FREQUENCY_UP_THRESHOLD (80)
+#define DEF_SAMPLING_DOWN_FACTOR (1)
+#define MAX_SAMPLING_DOWN_FACTOR (100000)
#define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3)
#define MICRO_FREQUENCY_UP_THRESHOLD (95)
#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000)
@@ -82,6 +84,7 @@ struct cpu_dbs_info_s {
unsigned int freq_lo;
unsigned int freq_lo_jiffies;
unsigned int freq_hi_jiffies;
+ unsigned int rate_mult;
int cpu;
unsigned int sample_type:1;
/*
@@ -108,10 +111,12 @@ static struct dbs_tuners {
unsigned int up_threshold;
unsigned int down_differential;
unsigned int ignore_nice;
+ unsigned int sampling_down_factor;
unsigned int powersave_bias;
unsigned int io_is_busy;
} dbs_tuners_ins = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
+ .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
.down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
.ignore_nice = 0,
.powersave_bias = 0,
@@ -259,6 +264,7 @@ static ssize_t show_##file_name \
show_one(sampling_rate, sampling_rate);
show_one(io_is_busy, io_is_busy);
show_one(up_threshold, up_threshold);
+show_one(sampling_down_factor, sampling_down_factor);
show_one(ignore_nice_load, ignore_nice);
show_one(powersave_bias, powersave_bias);
@@ -340,6 +346,29 @@ static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
return count;
}
+static ssize_t store_sampling_down_factor(struct kobject *a,
+ struct attribute *b, const char *buf, size_t count)
+{
+ unsigned int input, j;
+ int ret;
+ ret = sscanf(buf, "%u", &input);
+
+ if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
+ return -EINVAL;
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.sampling_down_factor = input;
+
+ /* Reset down sampling multiplier in case it was active */
+ for_each_online_cpu(j) {
+ struct cpu_dbs_info_s *dbs_info;
+ dbs_info = &per_cpu(od_cpu_dbs_info, j);
+ dbs_info->rate_mult = 1;
+ }
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
const char *buf, size_t count)
{
@@ -401,6 +430,7 @@ static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b,
define_one_global_rw(sampling_rate);
define_one_global_rw(io_is_busy);
define_one_global_rw(up_threshold);
+define_one_global_rw(sampling_down_factor);
define_one_global_rw(ignore_nice_load);
define_one_global_rw(powersave_bias);
@@ -409,6 +439,7 @@ static struct attribute *dbs_attributes[] = {
&sampling_rate_min.attr,
&sampling_rate.attr,
&up_threshold.attr,
+ &sampling_down_factor.attr,
&ignore_nice_load.attr,
&powersave_bias.attr,
&io_is_busy.attr,
@@ -562,6 +593,10 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
/* Check for frequency increase */
if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) {
+ /* If switching to max speed, apply sampling_down_factor */
+ if (policy->cur < policy->max)
+ this_dbs_info->rate_mult =
+ dbs_tuners_ins.sampling_down_factor;
dbs_freq_increase(policy, policy->max);
return;
}
@@ -584,6 +619,9 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
(dbs_tuners_ins.up_threshold -
dbs_tuners_ins.down_differential);
+ /* No longer fully busy, reset rate_mult */
+ this_dbs_info->rate_mult = 1;
+
if (freq_next < policy->min)
freq_next = policy->min;
@@ -607,7 +645,8 @@ static void do_dbs_timer(struct work_struct *work)
int sample_type = dbs_info->sample_type;
/* We want all CPUs to do sampling nearly on same jiffy */
- int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+ int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate
+ * dbs_info->rate_mult);
if (num_online_cpus() > 1)
delay -= jiffies % delay;
@@ -711,6 +750,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
}
}
this_dbs_info->cpu = cpu;
+ this_dbs_info->rate_mult = 1;
ondemand_powersave_bias_init_cpu(cpu);
/*
* Start the timerschedule work, when this governor