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)
+#define MIN_STAT_SAMPLING_RATE \
+ (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10))
+#define MIN_SAMPLING_RATE \
+ (def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
#define MAX_SAMPLING_RATE (500 * def_sampling_rate)
#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000)
#define TRANSITION_LATENCY_LIMIT (10 * 1000)
-static void do_dbs_timer(void *data);
+static void do_dbs_timer(struct work_struct *work);
+
+/* Sampling types */
+enum dbs_sample {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
struct cpu_dbs_info_s {
cputime64_t prev_cpu_idle;
cputime64_t prev_cpu_wall;
struct cpufreq_policy *cur_policy;
- struct work_struct work;
+ struct delayed_work work;
+ enum dbs_sample sample_type;
unsigned int enable;
+ struct cpufreq_frequency_table *freq_table;
+ unsigned int freq_lo;
+ unsigned int freq_lo_jiffies;
+ unsigned int freq_hi_jiffies;
};
static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
static struct workqueue_struct *kondemand_wq;
-struct dbs_tuners {
+static struct dbs_tuners {
unsigned int sampling_rate;
unsigned int up_threshold;
unsigned int ignore_nice;
-};
-
-static struct dbs_tuners dbs_tuners_ins = {
+ unsigned int powersave_bias;
+} dbs_tuners_ins = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
.ignore_nice = 0,
+ .powersave_bias = 0,
};
static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
return retval;
}
+/*
+ * Find right freq to be set now with powersave_bias on.
+ * Returns the freq_hi to be used right now and will set freq_hi_jiffies,
+ * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs.
+ */
+static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
+ unsigned int freq_next,
+ unsigned int relation)
+{
+ unsigned int freq_req, freq_reduc, freq_avg;
+ unsigned int freq_hi, freq_lo;
+ unsigned int index = 0;
+ unsigned int jiffies_total, jiffies_hi, jiffies_lo;
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, policy->cpu);
+
+ if (!dbs_info->freq_table) {
+ dbs_info->freq_lo = 0;
+ dbs_info->freq_lo_jiffies = 0;
+ return freq_next;
+ }
+
+ cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next,
+ relation, &index);
+ freq_req = dbs_info->freq_table[index].frequency;
+ freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000;
+ freq_avg = freq_req - freq_reduc;
+
+ /* Find freq bounds for freq_avg in freq_table */
+ index = 0;
+ cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg,
+ CPUFREQ_RELATION_H, &index);
+ freq_lo = dbs_info->freq_table[index].frequency;
+ index = 0;
+ cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg,
+ CPUFREQ_RELATION_L, &index);
+ freq_hi = dbs_info->freq_table[index].frequency;
+
+ /* Find out how long we have to be in hi and lo freqs */
+ if (freq_hi == freq_lo) {
+ dbs_info->freq_lo = 0;
+ dbs_info->freq_lo_jiffies = 0;
+ return freq_lo;
+ }
+ jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+ jiffies_hi = (freq_avg - freq_lo) * jiffies_total;
+ jiffies_hi += ((freq_hi - freq_lo) / 2);
+ jiffies_hi /= (freq_hi - freq_lo);
+ jiffies_lo = jiffies_total - jiffies_hi;
+ dbs_info->freq_lo = freq_lo;
+ dbs_info->freq_lo_jiffies = jiffies_lo;
+ dbs_info->freq_hi_jiffies = jiffies_hi;
+ return freq_hi;
+}
+
+static void ondemand_powersave_bias_init(void)
+{
+ int i;
+ for_each_online_cpu(i) {
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, i);
+ dbs_info->freq_table = cpufreq_frequency_get_table(i);
+ dbs_info->freq_lo = 0;
+ }
+}
+
/************************** sysfs interface ************************/
static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
{
show_one(sampling_rate, sampling_rate);
show_one(up_threshold, up_threshold);
show_one(ignore_nice_load, ignore_nice);
+show_one(powersave_bias, powersave_bias);
static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
const char *buf, size_t count)
ret = sscanf(buf, "%u", &input);
mutex_lock(&dbs_mutex);
- if (ret != 1 || input > MAX_SAMPLING_RATE || input < MIN_SAMPLING_RATE) {
+ if (ret != 1 || input > MAX_SAMPLING_RATE
+ || input < MIN_SAMPLING_RATE) {
mutex_unlock(&dbs_mutex);
return -EINVAL;
}
return count;
}
+static ssize_t store_powersave_bias(struct cpufreq_policy *unused,
+ const char *buf, size_t count)
+{
+ unsigned int input;
+ int ret;
+ ret = sscanf(buf, "%u", &input);
+
+ if (ret != 1)
+ return -EINVAL;
+
+ if (input > 1000)
+ input = 1000;
+
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.powersave_bias = input;
+ ondemand_powersave_bias_init();
+ mutex_unlock(&dbs_mutex);
+
+ return count;
+}
+
#define define_one_rw(_name) \
static struct freq_attr _name = \
__ATTR(_name, 0644, show_##_name, store_##_name)
define_one_rw(sampling_rate);
define_one_rw(up_threshold);
define_one_rw(ignore_nice_load);
+define_one_rw(powersave_bias);
static struct attribute * dbs_attributes[] = {
&sampling_rate_max.attr,
&sampling_rate.attr,
&up_threshold.attr,
&ignore_nice_load.attr,
+ &powersave_bias.attr,
NULL
};
if (!this_dbs_info->enable)
return;
+ this_dbs_info->freq_lo = 0;
policy = this_dbs_info->cur_policy;
cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
total_ticks = (unsigned int) cputime64_sub(cur_jiffies,
/* Check for frequency increase */
if (load > dbs_tuners_ins.up_threshold) {
/* if we are already at full speed then break out early */
- if (policy->cur == policy->max)
- return;
-
- __cpufreq_driver_target(policy, policy->max,
- CPUFREQ_RELATION_H);
+ if (!dbs_tuners_ins.powersave_bias) {
+ if (policy->cur == policy->max)
+ return;
+
+ __cpufreq_driver_target(policy, policy->max,
+ CPUFREQ_RELATION_H);
+ } else {
+ int freq = powersave_bias_target(policy, policy->max,
+ CPUFREQ_RELATION_H);
+ __cpufreq_driver_target(policy, freq,
+ CPUFREQ_RELATION_L);
+ }
return;
}
* policy. To be safe, we focus 10 points under the threshold.
*/
if (load < (dbs_tuners_ins.up_threshold - 10)) {
- unsigned int freq_next;
- freq_next = (policy->cur * load) /
+ unsigned int freq_next, freq_cur;
+
+ freq_cur = cpufreq_driver_getavg(policy);
+ if (!freq_cur)
+ freq_cur = policy->cur;
+
+ freq_next = (freq_cur * load) /
(dbs_tuners_ins.up_threshold - 10);
- __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_L);
+ if (!dbs_tuners_ins.powersave_bias) {
+ __cpufreq_driver_target(policy, freq_next,
+ CPUFREQ_RELATION_L);
+ } else {
+ int freq = powersave_bias_target(policy, freq_next,
+ CPUFREQ_RELATION_L);
+ __cpufreq_driver_target(policy, freq,
+ CPUFREQ_RELATION_L);
+ }
}
}
-static void do_dbs_timer(void *data)
+static void do_dbs_timer(struct work_struct *work)
{
unsigned int cpu = smp_processor_id();
struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
+ enum dbs_sample 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);
+
+ /* Permit rescheduling of this work item */
+ work_release(work);
+
+ delay -= jiffies % delay;
if (!dbs_info->enable)
return;
-
- lock_cpu_hotplug();
- dbs_check_cpu(dbs_info);
- unlock_cpu_hotplug();
- queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work,
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
+ /* Common NORMAL_SAMPLE setup */
+ dbs_info->sample_type = DBS_NORMAL_SAMPLE;
+ if (!dbs_tuners_ins.powersave_bias ||
+ sample_type == DBS_NORMAL_SAMPLE) {
+ lock_cpu_hotplug();
+ dbs_check_cpu(dbs_info);
+ unlock_cpu_hotplug();
+ if (dbs_info->freq_lo) {
+ /* Setup timer for SUB_SAMPLE */
+ dbs_info->sample_type = DBS_SUB_SAMPLE;
+ delay = dbs_info->freq_hi_jiffies;
+ }
+ } else {
+ __cpufreq_driver_target(dbs_info->cur_policy,
+ dbs_info->freq_lo,
+ CPUFREQ_RELATION_H);
+ }
+ queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay);
}
static inline void dbs_timer_init(unsigned int cpu)
{
struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
-
- INIT_WORK(&dbs_info->work, do_dbs_timer, 0);
- queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work,
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
- return;
+ /* We want all CPUs to do sampling nearly on same jiffy */
+ int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+ delay -= jiffies % delay;
+
+ ondemand_powersave_bias_init();
+ INIT_DELAYED_WORK_NAR(&dbs_info->work, do_dbs_timer);
+ dbs_info->sample_type = DBS_NORMAL_SAMPLE;
+ queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay);
}
static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
unsigned int cpu = policy->cpu;
struct cpu_dbs_info_s *this_dbs_info;
unsigned int j;
+ int rc;
this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
if (dbs_enable == 1) {
kondemand_wq = create_workqueue("kondemand");
if (!kondemand_wq) {
- printk(KERN_ERR "Creation of kondemand failed\n");
+ printk(KERN_ERR
+ "Creation of kondemand failed\n");
dbs_enable--;
mutex_unlock(&dbs_mutex);
return -ENOSPC;
}
}
+
+ rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
+ if (rc) {
+ if (dbs_enable == 1)
+ destroy_workqueue(kondemand_wq);
+ dbs_enable--;
+ mutex_unlock(&dbs_mutex);
+ return rc;
+ }
+
for_each_cpu_mask(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
j_dbs_info->prev_cpu_wall = get_jiffies_64();
}
this_dbs_info->enable = 1;
- sysfs_create_group(&policy->kobj, &dbs_attr_group);
/*
* Start the timerschedule work, when this governor
* is used for first time
git://git.onelab.eu / linux-2.6.git / blobdiff