#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>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+#include <linux/ktime.h>
+#include <linux/sched.h>
/*
* dbs is used in this file as a shortform for demandbased switching
* It helps to keep variable names smaller, simpler
*/
+#define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10)
#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)
-/*
- * 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;
#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 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);
+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);
+static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
+ unsigned int event);
+
+#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
+static
+#endif
+struct cpufreq_governor cpufreq_gov_ondemand = {
+ .name = "ondemand",
+ .governor = cpufreq_governor_dbs,
+ .max_transition_latency = TRANSITION_LATENCY_LIMIT,
+ .owner = THIS_MODULE,
+};
+
+/* Sampling types */
+enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
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;
+ cputime64_t prev_cpu_idle;
+ cputime64_t prev_cpu_iowait;
+ cputime64_t prev_cpu_wall;
+ cputime64_t prev_cpu_nice;
+ struct cpufreq_policy *cur_policy;
+ struct delayed_work work;
+ struct cpufreq_frequency_table *freq_table;
+ unsigned int freq_lo;
+ unsigned int freq_lo_jiffies;
+ unsigned int freq_hi_jiffies;
+ int cpu;
+ unsigned int sample_type:1;
+ /*
+ * percpu mutex that serializes governor limit change with
+ * do_dbs_timer invocation. We do not want do_dbs_timer to run
+ * when user is changing the governor or limits.
+ */
+ struct mutex timer_mutex;
};
-static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
+static DEFINE_PER_CPU(struct cpu_dbs_info_s, od_cpu_dbs_info);
static unsigned int dbs_enable; /* number of CPUs using this policy */
-static DECLARE_MUTEX (dbs_sem);
-static DECLARE_WORK (dbs_work, do_dbs_timer, NULL);
-
-struct dbs_tuners {
- unsigned int sampling_rate;
- unsigned int sampling_down_factor;
- unsigned int up_threshold;
- unsigned int ignore_nice;
+/*
+ * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on
+ * different CPUs. It protects dbs_enable in governor start/stop.
+ */
+static DEFINE_MUTEX(dbs_mutex);
+
+static struct workqueue_struct *kondemand_wq;
+
+static struct dbs_tuners {
+ unsigned int sampling_rate;
+ unsigned int up_threshold;
+ unsigned int down_differential;
+ unsigned int ignore_nice;
+ unsigned int powersave_bias;
+ unsigned int io_is_busy;
+} dbs_tuners_ins = {
+ .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
+ .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
+ .ignore_nice = 0,
+ .powersave_bias = 0,
};
-static struct dbs_tuners dbs_tuners_ins = {
- .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
- .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
-};
+static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
+ cputime64_t *wall)
+{
+ cputime64_t idle_time;
+ cputime64_t cur_wall_time;
+ cputime64_t busy_time;
-static inline unsigned int get_cpu_idle_time(unsigned int cpu)
+ cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
+ busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
+ kstat_cpu(cpu).cpustat.system);
+
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
+ busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice);
+
+ idle_time = cputime64_sub(cur_wall_time, busy_time);
+ if (wall)
+ *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);
+
+ return (cputime64_t)jiffies_to_usecs(idle_time);
+}
+
+static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
{
- return kstat_cpu(cpu).cpustat.idle +
- kstat_cpu(cpu).cpustat.iowait +
- ( dbs_tuners_ins.ignore_nice ?
- kstat_cpu(cpu).cpustat.nice :
- 0);
+ u64 idle_time = get_cpu_idle_time_us(cpu, wall);
+
+ if (idle_time == -1ULL)
+ return get_cpu_idle_time_jiffy(cpu, wall);
+
+ return idle_time;
}
-/************************** sysfs interface ************************/
-static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
+static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall)
{
- return sprintf (buf, "%u\n", MAX_SAMPLING_RATE);
+ u64 iowait_time = get_cpu_iowait_time_us(cpu, wall);
+
+ if (iowait_time == -1ULL)
+ return 0;
+
+ return iowait_time;
}
-static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
+/*
+ * 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)
{
- return sprintf (buf, "%u\n", MIN_SAMPLING_RATE);
+ 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(od_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;
}
-#define define_one_ro(_name) \
-static struct freq_attr _name = \
-__ATTR(_name, 0444, show_##_name, NULL)
+static void ondemand_powersave_bias_init_cpu(int cpu)
+{
+ struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
+ dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
+ dbs_info->freq_lo = 0;
+}
-define_one_ro(sampling_rate_max);
-define_one_ro(sampling_rate_min);
+static void ondemand_powersave_bias_init(void)
+{
+ int i;
+ for_each_online_cpu(i) {
+ ondemand_powersave_bias_init_cpu(i);
+ }
+}
+
+/************************** sysfs interface ************************/
+
+static ssize_t show_sampling_rate_max(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ printk_once(KERN_INFO "CPUFREQ: ondemand sampling_rate_max "
+ "sysfs file is deprecated - used by: %s\n", current->comm);
+ return sprintf(buf, "%u\n", -1U);
+}
+
+static ssize_t show_sampling_rate_min(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ return sprintf(buf, "%u\n", min_sampling_rate);
+}
+
+define_one_global_ro(sampling_rate_max);
+define_one_global_ro(sampling_rate_min);
/* cpufreq_ondemand Governor Tunables */
#define show_one(file_name, object) \
static ssize_t show_##file_name \
-(struct cpufreq_policy *unused, char *buf) \
+(struct kobject *kobj, struct attribute *attr, char *buf) \
{ \
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(io_is_busy, io_is_busy);
show_one(up_threshold, up_threshold);
show_one(ignore_nice_load, ignore_nice);
+show_one(powersave_bias, powersave_bias);
-static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
- const char *buf, size_t count)
+/*** delete after deprecation time ***/
+
+#define DEPRECATION_MSG(file_name) \
+ printk_once(KERN_INFO "CPUFREQ: Per core ondemand sysfs " \
+ "interface is deprecated - " #file_name "\n");
+
+#define show_one_old(file_name) \
+static ssize_t show_##file_name##_old \
+(struct cpufreq_policy *unused, char *buf) \
+{ \
+ printk_once(KERN_INFO "CPUFREQ: Per core ondemand sysfs " \
+ "interface is deprecated - " #file_name "\n"); \
+ return show_##file_name(NULL, NULL, buf); \
+}
+show_one_old(sampling_rate);
+show_one_old(up_threshold);
+show_one_old(ignore_nice_load);
+show_one_old(powersave_bias);
+show_one_old(sampling_rate_min);
+show_one_old(sampling_rate_max);
+
+cpufreq_freq_attr_ro_old(sampling_rate_min);
+cpufreq_freq_attr_ro_old(sampling_rate_max);
+
+/*** delete after deprecation time ***/
+
+static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b,
+ 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)
+ ret = sscanf(buf, "%u", &input);
+ if (ret != 1)
return -EINVAL;
- down(&dbs_sem);
- dbs_tuners_ins.sampling_down_factor = input;
- up(&dbs_sem);
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
+ mutex_unlock(&dbs_mutex);
return count;
}
-static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
- const char *buf, size_t count)
+static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b,
+ const char *buf, size_t count)
{
unsigned int input;
int ret;
- ret = sscanf (buf, "%u", &input);
- down(&dbs_sem);
- if (ret != 1 || input > MAX_SAMPLING_RATE || input < MIN_SAMPLING_RATE) {
- up(&dbs_sem);
+ ret = sscanf(buf, "%u", &input);
+ if (ret != 1)
return -EINVAL;
- }
- dbs_tuners_ins.sampling_rate = input;
- up(&dbs_sem);
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.io_is_busy = !!input;
+ mutex_unlock(&dbs_mutex);
return count;
}
-static ssize_t store_up_threshold(struct cpufreq_policy *unused,
- const char *buf, size_t count)
+static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
+ const char *buf, size_t count)
{
unsigned int input;
int ret;
- ret = sscanf (buf, "%u", &input);
+ ret = sscanf(buf, "%u", &input);
- down(&dbs_sem);
- if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
+ if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
input < MIN_FREQUENCY_UP_THRESHOLD) {
- up(&dbs_sem);
return -EINVAL;
}
+ mutex_lock(&dbs_mutex);
dbs_tuners_ins.up_threshold = input;
- up(&dbs_sem);
+ mutex_unlock(&dbs_mutex);
return count;
}
-static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
- const char *buf, size_t count)
+static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
+ const char *buf, size_t count)
{
unsigned int input;
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;
-
- down(&dbs_sem);
- if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */
- up(&dbs_sem);
+
+ mutex_lock(&dbs_mutex);
+ if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
+ mutex_unlock(&dbs_mutex);
return count;
}
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(od_cpu_dbs_info, j);
+ dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
+ &dbs_info->prev_cpu_wall);
+ if (dbs_tuners_ins.ignore_nice)
+ dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
+
}
- up(&dbs_sem);
+ mutex_unlock(&dbs_mutex);
return count;
}
-#define define_one_rw(_name) \
-static struct freq_attr _name = \
-__ATTR(_name, 0644, show_##_name, store_##_name)
+static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b,
+ 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;
-define_one_rw(sampling_rate);
-define_one_rw(sampling_down_factor);
-define_one_rw(up_threshold);
-define_one_rw(ignore_nice_load);
+ mutex_lock(&dbs_mutex);
+ dbs_tuners_ins.powersave_bias = input;
+ ondemand_powersave_bias_init();
+ mutex_unlock(&dbs_mutex);
-static struct attribute * dbs_attributes[] = {
+ return count;
+}
+
+define_one_global_rw(sampling_rate);
+define_one_global_rw(io_is_busy);
+define_one_global_rw(up_threshold);
+define_one_global_rw(ignore_nice_load);
+define_one_global_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,
+ &io_is_busy.attr,
NULL
};
.name = "ondemand",
};
+/*** delete after deprecation time ***/
+
+#define write_one_old(file_name) \
+static ssize_t store_##file_name##_old \
+(struct cpufreq_policy *unused, const char *buf, size_t count) \
+{ \
+ printk_once(KERN_INFO "CPUFREQ: Per core ondemand sysfs " \
+ "interface is deprecated - " #file_name "\n"); \
+ return store_##file_name(NULL, NULL, buf, count); \
+}
+write_one_old(sampling_rate);
+write_one_old(up_threshold);
+write_one_old(ignore_nice_load);
+write_one_old(powersave_bias);
+
+cpufreq_freq_attr_rw_old(sampling_rate);
+cpufreq_freq_attr_rw_old(up_threshold);
+cpufreq_freq_attr_rw_old(ignore_nice_load);
+cpufreq_freq_attr_rw_old(powersave_bias);
+
+static struct attribute *dbs_attributes_old[] = {
+ &sampling_rate_max_old.attr,
+ &sampling_rate_min_old.attr,
+ &sampling_rate_old.attr,
+ &up_threshold_old.attr,
+ &ignore_nice_load_old.attr,
+ &powersave_bias_old.attr,
+ NULL
+};
+
+static struct attribute_group dbs_attr_group_old = {
+ .attrs = dbs_attributes_old,
+ .name = "ondemand",
+};
+
+/*** delete after deprecation time ***/
+
/************************** 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 max_load_freq;
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;
- /*
+
+ /*
* 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.
*
- * Any frequency increase takes it to the maximum frequency.
- * Frequency reduction happens at minimum steps of
- * 5% (default) of current frequency
+ * Any frequency increase takes it to the maximum frequency.
+ * Frequency reduction happens at minimum steps of
+ * 5% (default) of current frequency
*/
- /* Check for frequency increase */
- idle_ticks = UINT_MAX;
- for_each_cpu_mask(j, policy->cpus) {
- unsigned int tmp_idle_ticks, total_idle_ticks;
+ /* Get Absolute Load - in terms of freq */
+ max_load_freq = 0;
+
+ for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
+ cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
+ unsigned int idle_time, wall_time, iowait_time;
+ unsigned int load, load_freq;
+ int freq_avg;
+
+ j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
+
+ cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
+ cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time);
+
+ wall_time = (unsigned int) cputime64_sub(cur_wall_time,
+ j_dbs_info->prev_cpu_wall);
+ j_dbs_info->prev_cpu_wall = cur_wall_time;
+
+ idle_time = (unsigned int) cputime64_sub(cur_idle_time,
+ j_dbs_info->prev_cpu_idle);
+ j_dbs_info->prev_cpu_idle = cur_idle_time;
+
+ iowait_time = (unsigned int) cputime64_sub(cur_iowait_time,
+ j_dbs_info->prev_cpu_iowait);
+ j_dbs_info->prev_cpu_iowait = cur_iowait_time;
+
+ if (dbs_tuners_ins.ignore_nice) {
+ cputime64_t cur_nice;
+ unsigned long cur_nice_jiffies;
+
+ cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice,
+ j_dbs_info->prev_cpu_nice);
+ /*
+ * Assumption: nice time between sampling periods will
+ * be less than 2^32 jiffies for 32 bit sys
+ */
+ cur_nice_jiffies = (unsigned long)
+ cputime64_to_jiffies64(cur_nice);
+
+ j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
+ idle_time += jiffies_to_usecs(cur_nice_jiffies);
+ }
- 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;
+ /*
+ * For the purpose of ondemand, waiting for disk IO is an
+ * indication that you're performance critical, and not that
+ * the system is actually idle. So subtract the iowait time
+ * from the cpu idle time.
+ */
- if (tmp_idle_ticks < idle_ticks)
- idle_ticks = tmp_idle_ticks;
- }
+ if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time)
+ idle_time -= iowait_time;
- /* 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 (unlikely(!wall_time || wall_time < idle_time))
+ continue;
- 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;
+ load = 100 * (wall_time - idle_time) / wall_time;
- j_dbs_info = &per_cpu(cpu_dbs_info, j);
- j_dbs_info->prev_cpu_idle_down =
- j_dbs_info->prev_cpu_idle_up;
- }
- /* 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);
- return;
+ freq_avg = __cpufreq_driver_getavg(policy, j);
+ if (freq_avg <= 0)
+ freq_avg = policy->cur;
+
+ load_freq = load * freq_avg;
+ if (load_freq > max_load_freq)
+ max_load_freq = load_freq;
}
- /* Check for frequency decrease */
- down_skip[cpu]++;
- if (down_skip[cpu] < dbs_tuners_ins.sampling_down_factor)
+ /* Check for frequency increase */
+ if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) {
+ /* if we are already at full speed then break out early */
+ 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;
-
- 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;
+ /* Check for frequency decrease */
/* 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) /
- (dbs_tuners_ins.up_threshold - 10);
+ if (max_load_freq <
+ (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) *
+ policy->cur) {
+ unsigned int freq_next;
+ freq_next = max_load_freq /
+ (dbs_tuners_ins.up_threshold -
+ dbs_tuners_ins.down_differential);
+
+ if (freq_next < policy->min)
+ freq_next = policy->min;
+
+ 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);
+ }
+ }
+}
- if (freq_next <= ((policy->cur * 95) / 100))
- __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_L);
+static void do_dbs_timer(struct work_struct *work)
+{
+ struct cpu_dbs_info_s *dbs_info =
+ container_of(work, struct cpu_dbs_info_s, work.work);
+ unsigned int cpu = dbs_info->cpu;
+ 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);
+
+ delay -= jiffies % delay;
+ mutex_lock(&dbs_info->timer_mutex);
+
+ /* Common NORMAL_SAMPLE setup */
+ dbs_info->sample_type = DBS_NORMAL_SAMPLE;
+ if (!dbs_tuners_ins.powersave_bias ||
+ sample_type == DBS_NORMAL_SAMPLE) {
+ dbs_check_cpu(dbs_info);
+ 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);
+ mutex_unlock(&dbs_info->timer_mutex);
}
-static void do_dbs_timer(void *data)
-{
- int i;
- down(&dbs_sem);
- for_each_online_cpu(i)
- dbs_check_cpu(i);
- schedule_delayed_work(&dbs_work,
- usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
- up(&dbs_sem);
-}
-
-static inline void dbs_timer_init(void)
+static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
{
- INIT_WORK(&dbs_work, do_dbs_timer, NULL);
- schedule_delayed_work(&dbs_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;
+
+ dbs_info->sample_type = DBS_NORMAL_SAMPLE;
+ INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer);
+ queue_delayed_work_on(dbs_info->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;
+ cancel_delayed_work_sync(&dbs_info->work);
+}
+
+/*
+ * Not all CPUs want IO time to be accounted as busy; this dependson how
+ * efficient idling at a higher frequency/voltage is.
+ * Pavel Machek says this is not so for various generations of AMD and old
+ * Intel systems.
+ * Mike Chan (androidlcom) calis this is also not true for ARM.
+ * Because of this, whitelist specific known (series) of CPUs by default, and
+ * leave all others up to the user.
+ */
+static int should_io_be_busy(void)
+{
+#if defined(CONFIG_X86)
+ /*
+ * For Intel, Core 2 (model 15) andl later have an efficient idle.
+ */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ boot_cpu_data.x86 == 6 &&
+ boot_cpu_data.x86_model >= 15)
+ return 1;
+#endif
+ return 0;
}
static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
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);
+ this_dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
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 >
- (TRANSITION_LATENCY_LIMIT * 1000))
- return -EINVAL;
- if (this_dbs_info->enable) /* Already enabled */
- break;
-
- down(&dbs_sem);
- for_each_cpu_mask(j, policy->cpus) {
+ mutex_lock(&dbs_mutex);
+
+ rc = sysfs_create_group(&policy->kobj, &dbs_attr_group_old);
+ if (rc) {
+ mutex_unlock(&dbs_mutex);
+ return rc;
+ }
+
+ dbs_enable++;
+ for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
- j_dbs_info = &per_cpu(cpu_dbs_info, j);
+ j_dbs_info = &per_cpu(od_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);
+ if (dbs_tuners_ins.ignore_nice) {
+ j_dbs_info->prev_cpu_nice =
+ kstat_cpu(j).cpustat.nice;
+ }
}
- this_dbs_info->enable = 1;
- sysfs_create_group(&policy->kobj, &dbs_attr_group);
- dbs_enable++;
+ this_dbs_info->cpu = cpu;
+ ondemand_powersave_bias_init_cpu(cpu);
/*
* Start the timerschedule work, when this governor
* is used for first time
*/
if (dbs_enable == 1) {
unsigned int latency;
+
+ rc = sysfs_create_group(cpufreq_global_kobject,
+ &dbs_attr_group);
+ if (rc) {
+ mutex_unlock(&dbs_mutex);
+ return rc;
+ }
+
/* policy latency is in nS. Convert it to uS first */
latency = policy->cpuinfo.transition_latency / 1000;
if (latency == 0)
latency = 1;
-
- def_sampling_rate = latency *
- DEF_SAMPLING_RATE_LATENCY_MULTIPLIER;
-
- if (def_sampling_rate < MIN_STAT_SAMPLING_RATE)
- def_sampling_rate = MIN_STAT_SAMPLING_RATE;
-
- dbs_tuners_ins.sampling_rate = def_sampling_rate;
- dbs_tuners_ins.ignore_nice = 0;
-
- dbs_timer_init();
+ /* 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_tuners_ins.io_is_busy = should_io_be_busy();
}
-
- up(&dbs_sem);
+ mutex_unlock(&dbs_mutex);
+
+ mutex_init(&this_dbs_info->timer_mutex);
+ dbs_timer_init(this_dbs_info);
break;
case CPUFREQ_GOV_STOP:
- down(&dbs_sem);
- this_dbs_info->enable = 0;
- sysfs_remove_group(&policy->kobj, &dbs_attr_group);
+ dbs_timer_exit(this_dbs_info);
+
+ mutex_lock(&dbs_mutex);
+ sysfs_remove_group(&policy->kobj, &dbs_attr_group_old);
+ mutex_destroy(&this_dbs_info->timer_mutex);
dbs_enable--;
- /*
- * Stop the timerschedule work, when this governor
- * is used for first time
- */
- if (dbs_enable == 0)
- dbs_timer_exit();
-
- up(&dbs_sem);
+ mutex_unlock(&dbs_mutex);
+ if (!dbs_enable)
+ sysfs_remove_group(cpufreq_global_kobject,
+ &dbs_attr_group);
break;
case CPUFREQ_GOV_LIMITS:
- down(&dbs_sem);
+ mutex_lock(&this_dbs_info->timer_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);
- up(&dbs_sem);
+ __cpufreq_driver_target(this_dbs_info->cur_policy,
+ policy->min, CPUFREQ_RELATION_L);
+ mutex_unlock(&this_dbs_info->timer_mutex);
break;
}
return 0;
}
-static struct cpufreq_governor cpufreq_gov_dbs = {
- .name = "ondemand",
- .governor = cpufreq_governor_dbs,
- .owner = THIS_MODULE,
-};
-
static int __init cpufreq_gov_dbs_init(void)
{
- return cpufreq_register_governor(&cpufreq_gov_dbs);
+ int err;
+ cputime64_t wall;
+ u64 idle_time;
+ int cpu = get_cpu();
+
+ idle_time = get_cpu_idle_time_us(cpu, &wall);
+ put_cpu();
+ if (idle_time != -1ULL) {
+ /* Idle micro accounting is supported. Use finer thresholds */
+ 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");
+ if (!kondemand_wq) {
+ printk(KERN_ERR "Creation of kondemand failed\n");
+ return -EFAULT;
+ }
+ err = cpufreq_register_governor(&cpufreq_gov_ondemand);
+ if (err)
+ destroy_workqueue(kondemand_wq);
+
+ return err;
}
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);
+ cpufreq_unregister_governor(&cpufreq_gov_ondemand);
+ destroy_workqueue(kondemand_wq);
}
-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");
+#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
+fs_initcall(cpufreq_gov_dbs_init);
+#else
module_init(cpufreq_gov_dbs_init);
+#endif
module_exit(cpufreq_gov_dbs_exit);
Code Review / linux-2.6.git / blobdiff