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path: root/drivers/cpufreq/cpufreq_conservative.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq_conservative.c')
-rw-r--r--drivers/cpufreq/cpufreq_conservative.c153
1 files changed, 90 insertions, 63 deletions
diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index 4bd33ce8a6f..1bba99747f5 100644
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -37,17 +37,17 @@
#define DEF_FREQUENCY_UP_THRESHOLD (80)
#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
-/*
- * The polling frequency of this governor depends on the capability of
+/*
+ * The polling frequency of this governor depends on the capability of
* the processor. Default polling frequency is 1000 times the transition
- * latency of the processor. The governor will work on any processor with
- * transition latency <= 10mS, using appropriate sampling
+ * latency of the processor. The governor will work on any processor with
+ * transition latency <= 10mS, using appropriate sampling
* rate.
* For CPUs with transition latency > 10mS (mostly drivers
* with CPUFREQ_ETERNAL), this governor will not work.
* All times here are in uS.
*/
-static unsigned int def_sampling_rate;
+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 \
@@ -63,12 +63,12 @@ static unsigned int def_sampling_rate;
static void do_dbs_timer(struct work_struct *work);
struct cpu_dbs_info_s {
- struct cpufreq_policy *cur_policy;
- unsigned int prev_cpu_idle_up;
- unsigned int prev_cpu_idle_down;
- unsigned int enable;
- unsigned int down_skip;
- unsigned int requested_freq;
+ struct cpufreq_policy *cur_policy;
+ unsigned int prev_cpu_idle_up;
+ unsigned int prev_cpu_idle_down;
+ unsigned int enable;
+ unsigned int down_skip;
+ unsigned int requested_freq;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
@@ -82,24 +82,24 @@ static unsigned int dbs_enable; /* number of CPUs using this policy */
* cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
* is recursive for the same process. -Venki
*/
-static DEFINE_MUTEX (dbs_mutex);
+static DEFINE_MUTEX (dbs_mutex);
static DECLARE_DELAYED_WORK(dbs_work, do_dbs_timer);
struct dbs_tuners {
- unsigned int sampling_rate;
- unsigned int sampling_down_factor;
- unsigned int up_threshold;
- unsigned int down_threshold;
- unsigned int ignore_nice;
- unsigned int freq_step;
+ unsigned int sampling_rate;
+ unsigned int sampling_down_factor;
+ unsigned int up_threshold;
+ unsigned int down_threshold;
+ unsigned int ignore_nice;
+ unsigned int freq_step;
};
static struct dbs_tuners dbs_tuners_ins = {
- .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
- .down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
- .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
- .ignore_nice = 0,
- .freq_step = 5,
+ .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
+ .down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
+ .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
+ .ignore_nice = 0,
+ .freq_step = 5,
};
static inline unsigned int get_cpu_idle_time(unsigned int cpu)
@@ -109,13 +109,34 @@ static inline unsigned int get_cpu_idle_time(unsigned int cpu)
if (dbs_tuners_ins.ignore_nice)
add_nice = kstat_cpu(cpu).cpustat.nice;
- ret = kstat_cpu(cpu).cpustat.idle +
+ ret = kstat_cpu(cpu).cpustat.idle +
kstat_cpu(cpu).cpustat.iowait +
add_nice;
return ret;
}
+/* keep track of frequency transitions */
+static int
+dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct cpufreq_freqs *freq = data;
+ struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info,
+ freq->cpu);
+
+ if (!this_dbs_info->enable)
+ return 0;
+
+ this_dbs_info->requested_freq = freq->new;
+
+ return 0;
+}
+
+static struct notifier_block dbs_cpufreq_notifier_block = {
+ .notifier_call = dbs_cpufreq_notifier
+};
+
/************************** sysfs interface ************************/
static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
{
@@ -127,8 +148,8 @@ static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
return sprintf (buf, "%u\n", MIN_SAMPLING_RATE);
}
-#define define_one_ro(_name) \
-static struct freq_attr _name = \
+#define define_one_ro(_name) \
+static struct freq_attr _name = \
__ATTR(_name, 0444, show_##_name, NULL)
define_one_ro(sampling_rate_max);
@@ -148,7 +169,7 @@ show_one(down_threshold, down_threshold);
show_one(ignore_nice_load, ignore_nice);
show_one(freq_step, freq_step);
-static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
+static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
const char *buf, size_t count)
{
unsigned int input;
@@ -164,7 +185,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
return count;
}
-static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
+static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
const char *buf, size_t count)
{
unsigned int input;
@@ -183,7 +204,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
return count;
}
-static ssize_t store_up_threshold(struct cpufreq_policy *unused,
+static ssize_t store_up_threshold(struct cpufreq_policy *unused,
const char *buf, size_t count)
{
unsigned int input;
@@ -202,7 +223,7 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused,
return count;
}
-static ssize_t store_down_threshold(struct cpufreq_policy *unused,
+static ssize_t store_down_threshold(struct cpufreq_policy *unused,
const char *buf, size_t count)
{
unsigned int input;
@@ -228,16 +249,16 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
int ret;
unsigned int j;
-
- ret = sscanf (buf, "%u", &input);
- if ( ret != 1 )
+
+ ret = sscanf(buf, "%u", &input);
+ if (ret != 1)
return -EINVAL;
- if ( input > 1 )
+ if (input > 1)
input = 1;
-
+
mutex_lock(&dbs_mutex);
- if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */
+ if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
mutex_unlock(&dbs_mutex);
return count;
}
@@ -261,14 +282,14 @@ static ssize_t store_freq_step(struct cpufreq_policy *policy,
unsigned int input;
int ret;
- ret = sscanf (buf, "%u", &input);
+ ret = sscanf(buf, "%u", &input);
- if ( ret != 1 )
+ if (ret != 1)
return -EINVAL;
- if ( input > 100 )
+ 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 :) */
mutex_lock(&dbs_mutex);
@@ -322,18 +343,18 @@ static void dbs_check_cpu(int cpu)
policy = this_dbs_info->cur_policy;
- /*
- * The default safe range is 20% to 80%
+ /*
+ * The default safe range is 20% to 80%
* Every sampling_rate, we check
- * - If current idle time is less than 20%, then we try to
- * increase frequency
+ * - If current idle time is less than 20%, then we try to
+ * increase frequency
* Every sampling_rate*sampling_down_factor, we check
- * - If current idle time is more than 80%, then we try to
- * decrease frequency
+ * - If current idle time is more than 80%, then we try to
+ * decrease frequency
*
- * Any frequency increase takes it to the maximum frequency.
- * Frequency reduction happens at minimum steps of
- * 5% (default) of max_frequency
+ * Any frequency increase takes it to the maximum frequency.
+ * Frequency reduction happens at minimum steps of
+ * 5% (default) of max_frequency
*/
/* Check for frequency increase */
@@ -361,13 +382,13 @@ static void dbs_check_cpu(int cpu)
/* if we are already at full speed then break out early */
if (this_dbs_info->requested_freq == policy->max)
return;
-
+
freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100;
/* max freq cannot be less than 100. But who knows.... */
if (unlikely(freq_step == 0))
freq_step = 5;
-
+
this_dbs_info->requested_freq += freq_step;
if (this_dbs_info->requested_freq > policy->max)
this_dbs_info->requested_freq = policy->max;
@@ -427,15 +448,15 @@ static void dbs_check_cpu(int cpu)
}
static void do_dbs_timer(struct work_struct *work)
-{
+{
int i;
mutex_lock(&dbs_mutex);
for_each_online_cpu(i)
dbs_check_cpu(i);
- schedule_delayed_work(&dbs_work,
+ schedule_delayed_work(&dbs_work,
usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
mutex_unlock(&dbs_mutex);
-}
+}
static inline void dbs_timer_init(void)
{
@@ -462,13 +483,12 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
switch (event) {
case CPUFREQ_GOV_START:
- if ((!cpu_online(cpu)) ||
- (!policy->cur))
+ if ((!cpu_online(cpu)) || (!policy->cur))
return -EINVAL;
if (this_dbs_info->enable) /* Already enabled */
break;
-
+
mutex_lock(&dbs_mutex);
rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
@@ -481,7 +501,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
j_dbs_info->cur_policy = policy;
-
+
j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(cpu);
j_dbs_info->prev_cpu_idle_down
= j_dbs_info->prev_cpu_idle_up;
@@ -511,8 +531,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
dbs_tuners_ins.sampling_rate = def_sampling_rate;
dbs_timer_init();
+ cpufreq_register_notifier(
+ &dbs_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
}
-
+
mutex_unlock(&dbs_mutex);
break;
@@ -525,9 +548,13 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
* Stop the timerschedule work, when this governor
* is used for first time
*/
- if (dbs_enable == 0)
+ if (dbs_enable == 0) {
dbs_timer_exit();
-
+ cpufreq_unregister_notifier(
+ &dbs_cpufreq_notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ }
+
mutex_unlock(&dbs_mutex);
break;
@@ -537,11 +564,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
if (policy->max < this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(
this_dbs_info->cur_policy,
- policy->max, CPUFREQ_RELATION_H);
+ policy->max, CPUFREQ_RELATION_H);
else if (policy->min > this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(
this_dbs_info->cur_policy,
- policy->min, CPUFREQ_RELATION_L);
+ policy->min, CPUFREQ_RELATION_L);
mutex_unlock(&dbs_mutex);
break;
}