#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/smp.h>
#include <linux/init.h>
-#include <linux/interrupt.h>
-#include <linux/ctype.h>
#include <linux/cpufreq.h>
-#include <linux/sysctl.h>
-#include <linux/types.h>
-#include <linux/fs.h>
-#include <linux/sysfs.h>
-#include <linux/sched.h>
-#include <linux/kmod.h>
-#include <linux/workqueue.h>
+#include <linux/cpu.h>
#include <linux/jiffies.h>
#include <linux/kernel_stat.h>
-#include <linux/percpu.h>
#include <linux/mutex.h>
/*
#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 DEF_SAMPLING_DOWN_FACTOR (1)
-#define MAX_SAMPLING_DOWN_FACTOR (10)
#define TRANSITION_LATENCY_LIMIT (10 * 1000)
static void do_dbs_timer(void *data);
struct cpu_dbs_info_s {
+ cputime64_t prev_cpu_idle;
+ cputime64_t prev_cpu_wall;
struct cpufreq_policy *cur_policy;
- unsigned int prev_cpu_idle_up;
- unsigned int prev_cpu_idle_down;
+ struct work_struct work;
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 unsigned int dbs_enable; /* number of CPUs using this policy */
-static DEFINE_MUTEX (dbs_mutex);
-static DECLARE_WORK (dbs_work, do_dbs_timer, NULL);
+/*
+ * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
+ * lock and dbs_mutex. cpu_hotplug lock should always be held before
+ * dbs_mutex. If any function that can potentially take cpu_hotplug lock
+ * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
+ * 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);
-struct dbs_tuners {
+static struct workqueue_struct *kondemand_wq;
+
+static struct dbs_tuners {
unsigned int sampling_rate;
- unsigned int sampling_down_factor;
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,
- .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
.ignore_nice = 0,
+ .powersave_bias = 0,
};
-static inline unsigned int get_cpu_idle_time(unsigned int cpu)
+static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
{
- return kstat_cpu(cpu).cpustat.idle +
- kstat_cpu(cpu).cpustat.iowait +
- ( dbs_tuners_ins.ignore_nice ?
- kstat_cpu(cpu).cpustat.nice :
- 0);
+ cputime64_t retval;
+
+ retval = cputime64_add(kstat_cpu(cpu).cpustat.idle,
+ kstat_cpu(cpu).cpustat.iowait);
+
+ if (dbs_tuners_ins.ignore_nice)
+ retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice);
+
+ 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 ************************/
return sprintf(buf, "%u\n", dbs_tuners_ins.object); \
}
show_one(sampling_rate, sampling_rate);
-show_one(sampling_down_factor, sampling_down_factor);
show_one(up_threshold, up_threshold);
show_one(ignore_nice_load, ignore_nice);
-
-static ssize_t store_sampling_down_factor(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 > MAX_SAMPLING_DOWN_FACTOR || input < 1)
- return -EINVAL;
-
- mutex_lock(&dbs_mutex);
- dbs_tuners_ins.sampling_down_factor = input;
- mutex_unlock(&dbs_mutex);
-
- return count;
-}
+show_one(powersave_bias, powersave_bias);
static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
const char *buf, size_t count)
{
unsigned int input;
int ret;
- ret = sscanf (buf, "%u", &input);
+ ret = sscanf(buf, "%u", &input);
mutex_lock(&dbs_mutex);
if (ret != 1 || input > MAX_SAMPLING_RATE || input < MIN_SAMPLING_RATE) {
{
unsigned int input;
int ret;
- ret = sscanf (buf, "%u", &input);
+ ret = sscanf(buf, "%u", &input);
mutex_lock(&dbs_mutex);
if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
unsigned int j;
- ret = sscanf (buf, "%u", &input);
+ ret = sscanf(buf, "%u", &input);
if ( ret != 1 )
return -EINVAL;
}
dbs_tuners_ins.ignore_nice = input;
- /* we need to re-evaluate prev_cpu_idle_up and prev_cpu_idle_down */
+ /* we need to re-evaluate prev_cpu_idle */
for_each_online_cpu(j) {
- struct cpu_dbs_info_s *j_dbs_info;
- j_dbs_info = &per_cpu(cpu_dbs_info, j);
- j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j);
- j_dbs_info->prev_cpu_idle_down = j_dbs_info->prev_cpu_idle_up;
+ struct cpu_dbs_info_s *dbs_info;
+ dbs_info = &per_cpu(cpu_dbs_info, j);
+ dbs_info->prev_cpu_idle = get_cpu_idle_time(j);
+ dbs_info->prev_cpu_wall = get_jiffies_64();
}
mutex_unlock(&dbs_mutex);
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(sampling_down_factor);
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_min.attr,
&sampling_rate.attr,
- &sampling_down_factor.attr,
&up_threshold.attr,
&ignore_nice_load.attr,
+ &powersave_bias.attr,
NULL
};
/************************** sysfs end ************************/
-static void dbs_check_cpu(int cpu)
+static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
{
- unsigned int idle_ticks, up_idle_ticks, total_ticks;
- unsigned int freq_next;
- unsigned int freq_down_sampling_rate;
- static int down_skip[NR_CPUS];
- struct cpu_dbs_info_s *this_dbs_info;
+ unsigned int idle_ticks, total_ticks;
+ unsigned int load;
+ cputime64_t cur_jiffies;
struct cpufreq_policy *policy;
unsigned int j;
- this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
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,
+ this_dbs_info->prev_cpu_wall);
+ this_dbs_info->prev_cpu_wall = cur_jiffies;
+ if (!total_ticks)
+ return;
/*
* Every sampling_rate, we check, if current idle time is less
* than 20% (default), then we try to increase frequency
- * Every sampling_rate*sampling_down_factor, we look for a the lowest
+ * Every sampling_rate, we look for a the lowest
* frequency which can sustain the load while keeping idle time over
* 30%. If such a frequency exist, we try to decrease to this frequency.
*
* 5% (default) of current frequency
*/
- /* Check for frequency increase */
+ /* Get Idle Time */
idle_ticks = UINT_MAX;
for_each_cpu_mask(j, policy->cpus) {
- unsigned int tmp_idle_ticks, total_idle_ticks;
+ cputime64_t total_idle_ticks;
+ unsigned int tmp_idle_ticks;
struct cpu_dbs_info_s *j_dbs_info;
j_dbs_info = &per_cpu(cpu_dbs_info, j);
total_idle_ticks = get_cpu_idle_time(j);
- tmp_idle_ticks = total_idle_ticks -
- j_dbs_info->prev_cpu_idle_up;
- j_dbs_info->prev_cpu_idle_up = total_idle_ticks;
+ tmp_idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks,
+ j_dbs_info->prev_cpu_idle);
+ j_dbs_info->prev_cpu_idle = total_idle_ticks;
if (tmp_idle_ticks < idle_ticks)
idle_ticks = tmp_idle_ticks;
}
+ load = (100 * (total_ticks - idle_ticks)) / total_ticks;
- /* Scale idle ticks by 100 and compare with up and down ticks */
- idle_ticks *= 100;
- up_idle_ticks = (100 - dbs_tuners_ins.up_threshold) *
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
-
- if (idle_ticks < up_idle_ticks) {
- down_skip[cpu] = 0;
- 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_idle_down =
- j_dbs_info->prev_cpu_idle_up;
- }
+ /* 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;
}
/* Check for frequency decrease */
- down_skip[cpu]++;
- if (down_skip[cpu] < dbs_tuners_ins.sampling_down_factor)
- return;
-
- idle_ticks = UINT_MAX;
- for_each_cpu_mask(j, policy->cpus) {
- unsigned int tmp_idle_ticks, total_idle_ticks;
- struct cpu_dbs_info_s *j_dbs_info;
-
- j_dbs_info = &per_cpu(cpu_dbs_info, j);
- /* Check for frequency decrease */
- total_idle_ticks = j_dbs_info->prev_cpu_idle_up;
- tmp_idle_ticks = total_idle_ticks -
- j_dbs_info->prev_cpu_idle_down;
- j_dbs_info->prev_cpu_idle_down = total_idle_ticks;
-
- if (tmp_idle_ticks < idle_ticks)
- idle_ticks = tmp_idle_ticks;
- }
-
- down_skip[cpu] = 0;
/* if we cannot reduce the frequency anymore, break out early */
if (policy->cur == policy->min)
return;
- /* Compute how many ticks there are between two measurements */
- freq_down_sampling_rate = dbs_tuners_ins.sampling_rate *
- dbs_tuners_ins.sampling_down_factor;
- total_ticks = usecs_to_jiffies(freq_down_sampling_rate);
-
/*
* The optimal frequency is the frequency that is the lowest that
* can support the current CPU usage without triggering the up
* policy. To be safe, we focus 10 points under the threshold.
*/
- freq_next = ((total_ticks - idle_ticks) * 100) / total_ticks;
- freq_next = (freq_next * policy->cur) /
+ if (load < (dbs_tuners_ins.up_threshold - 10)) {
+ unsigned int freq_next = (policy->cur * load) /
(dbs_tuners_ins.up_threshold - 10);
-
- if (freq_next < policy->min)
- freq_next = policy->min;
-
- if (freq_next <= ((policy->cur * 95) / 100))
- __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);
+ }
+ }
}
+/* Sampling types */
+enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
+
static void do_dbs_timer(void *data)
{
- int i;
- mutex_lock(&dbs_mutex);
- for_each_online_cpu(i)
- dbs_check_cpu(i);
- schedule_delayed_work(&dbs_work,
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
- mutex_unlock(&dbs_mutex);
+ unsigned int cpu = smp_processor_id();
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
+ /* We want all CPUs to do sampling nearly on same jiffy */
+ int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+ delay -= jiffies % delay;
+
+ if (!dbs_info->enable)
+ return;
+ /* Common NORMAL_SAMPLE setup */
+ INIT_WORK(&dbs_info->work, do_dbs_timer, (void *)DBS_NORMAL_SAMPLE);
+ if (!dbs_tuners_ins.powersave_bias ||
+ (unsigned long) data == DBS_NORMAL_SAMPLE) {
+ lock_cpu_hotplug();
+ dbs_check_cpu(dbs_info);
+ unlock_cpu_hotplug();
+ if (dbs_info->freq_lo) {
+ /* Setup timer for SUB_SAMPLE */
+ INIT_WORK(&dbs_info->work, do_dbs_timer,
+ (void *)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(void)
+static inline void dbs_timer_init(unsigned int cpu)
{
- INIT_WORK(&dbs_work, do_dbs_timer, NULL);
- schedule_delayed_work(&dbs_work,
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
- return;
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu);
+ /* 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_WORK(&dbs_info->work, do_dbs_timer, NULL);
+ queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay);
}
-static inline void dbs_timer_exit(void)
+static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
{
- cancel_delayed_work(&dbs_work);
- return;
+ dbs_info->enable = 0;
+ cancel_delayed_work(&dbs_info->work);
+ flush_workqueue(kondemand_wq);
}
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 (policy->cpuinfo.transition_latency >
break;
mutex_lock(&dbs_mutex);
+ dbs_enable++;
+ if (dbs_enable == 1) {
+ kondemand_wq = create_workqueue("kondemand");
+ if (!kondemand_wq) {
+ printk(KERN_ERR "Creation of kondemand failed\n");
+ dbs_enable--;
+ mutex_unlock(&dbs_mutex);
+ return -ENOSPC;
+ }
+ }
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->cur_policy = policy;
- j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j);
- j_dbs_info->prev_cpu_idle_down
- = j_dbs_info->prev_cpu_idle_up;
+ j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j);
+ j_dbs_info->prev_cpu_wall = get_jiffies_64();
}
this_dbs_info->enable = 1;
sysfs_create_group(&policy->kobj, &dbs_attr_group);
- dbs_enable++;
/*
* Start the timerschedule work, when this governor
* is used for first time
def_sampling_rate = MIN_STAT_SAMPLING_RATE;
dbs_tuners_ins.sampling_rate = def_sampling_rate;
- dbs_timer_init();
}
+ dbs_timer_init(policy->cpu);
mutex_unlock(&dbs_mutex);
break;
case CPUFREQ_GOV_STOP:
mutex_lock(&dbs_mutex);
- this_dbs_info->enable = 0;
+ dbs_timer_exit(this_dbs_info);
sysfs_remove_group(&policy->kobj, &dbs_attr_group);
dbs_enable--;
- /*
- * Stop the timerschedule work, when this governor
- * is used for first time
- */
if (dbs_enable == 0)
- dbs_timer_exit();
+ destroy_workqueue(kondemand_wq);
mutex_unlock(&dbs_mutex);
case CPUFREQ_GOV_LIMITS:
mutex_lock(&dbs_mutex);
if (policy->max < this_dbs_info->cur_policy->cur)
- __cpufreq_driver_target(
- this_dbs_info->cur_policy,
- policy->max, CPUFREQ_RELATION_H);
+ __cpufreq_driver_target(this_dbs_info->cur_policy,
+ 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);
+ __cpufreq_driver_target(this_dbs_info->cur_policy,
+ policy->min,
+ CPUFREQ_RELATION_L);
mutex_unlock(&dbs_mutex);
break;
}
}
static struct cpufreq_governor cpufreq_gov_dbs = {
- .name = "ondemand",
- .governor = cpufreq_governor_dbs,
- .owner = THIS_MODULE,
+ .name = "ondemand",
+ .governor = cpufreq_governor_dbs,
+ .owner = THIS_MODULE,
};
static int __init cpufreq_gov_dbs_init(void)
static void __exit cpufreq_gov_dbs_exit(void)
{
- /* Make sure that the scheduled work is indeed not running */
- flush_scheduled_work();
-
cpufreq_unregister_governor(&cpufreq_gov_dbs);
}
-MODULE_AUTHOR ("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
-MODULE_DESCRIPTION ("'cpufreq_ondemand' - A dynamic cpufreq governor for "
- "Low Latency Frequency Transition capable processors");
-MODULE_LICENSE ("GPL");
+MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
+MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
+MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "
+ "Low Latency Frequency Transition capable processors");
+MODULE_LICENSE("GPL");
module_init(cpufreq_gov_dbs_init);
module_exit(cpufreq_gov_dbs_exit);
git.openpandora.org / pandora-kernel.git / blobdiff