![Quentin Perret](/assets/img/avatar_default.png)
Currently, most CPUFreq governors are registered at the core_initcall time when the given governor is the default one, and the module_init time otherwise. In preparation for letting users specify the default governor on the kernel command line, change all of them to be registered at the core_initcall unconditionally, as it is already the case for the schedutil and performance governors. This will allow us to assume that builtin governors have been registered before the built-in CPUFreq drivers probe. And since all governors have similar init/exit patterns now, introduce two new macros, cpufreq_governor_{init,exit}(), to factorize the code. Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
342 lines
8.7 KiB
C
342 lines
8.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* drivers/cpufreq/cpufreq_conservative.c
|
|
*
|
|
* Copyright (C) 2001 Russell King
|
|
* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
|
|
* Jun Nakajima <jun.nakajima@intel.com>
|
|
* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
|
|
*/
|
|
|
|
#include <linux/slab.h>
|
|
#include "cpufreq_governor.h"
|
|
|
|
struct cs_policy_dbs_info {
|
|
struct policy_dbs_info policy_dbs;
|
|
unsigned int down_skip;
|
|
unsigned int requested_freq;
|
|
};
|
|
|
|
static inline struct cs_policy_dbs_info *to_dbs_info(struct policy_dbs_info *policy_dbs)
|
|
{
|
|
return container_of(policy_dbs, struct cs_policy_dbs_info, policy_dbs);
|
|
}
|
|
|
|
struct cs_dbs_tuners {
|
|
unsigned int down_threshold;
|
|
unsigned int freq_step;
|
|
};
|
|
|
|
/* Conservative governor macros */
|
|
#define DEF_FREQUENCY_UP_THRESHOLD (80)
|
|
#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
|
|
#define DEF_FREQUENCY_STEP (5)
|
|
#define DEF_SAMPLING_DOWN_FACTOR (1)
|
|
#define MAX_SAMPLING_DOWN_FACTOR (10)
|
|
|
|
static inline unsigned int get_freq_step(struct cs_dbs_tuners *cs_tuners,
|
|
struct cpufreq_policy *policy)
|
|
{
|
|
unsigned int freq_step = (cs_tuners->freq_step * policy->max) / 100;
|
|
|
|
/* max freq cannot be less than 100. But who knows... */
|
|
if (unlikely(freq_step == 0))
|
|
freq_step = DEF_FREQUENCY_STEP;
|
|
|
|
return freq_step;
|
|
}
|
|
|
|
/*
|
|
* 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 check, if current idle time is more than 80%
|
|
* (default), then we try to decrease frequency
|
|
*
|
|
* Frequency updates happen at minimum steps of 5% (default) of maximum
|
|
* frequency
|
|
*/
|
|
static unsigned int cs_dbs_update(struct cpufreq_policy *policy)
|
|
{
|
|
struct policy_dbs_info *policy_dbs = policy->governor_data;
|
|
struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
|
|
unsigned int requested_freq = dbs_info->requested_freq;
|
|
struct dbs_data *dbs_data = policy_dbs->dbs_data;
|
|
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
|
|
unsigned int load = dbs_update(policy);
|
|
unsigned int freq_step;
|
|
|
|
/*
|
|
* break out if we 'cannot' reduce the speed as the user might
|
|
* want freq_step to be zero
|
|
*/
|
|
if (cs_tuners->freq_step == 0)
|
|
goto out;
|
|
|
|
/*
|
|
* If requested_freq is out of range, it is likely that the limits
|
|
* changed in the meantime, so fall back to current frequency in that
|
|
* case.
|
|
*/
|
|
if (requested_freq > policy->max || requested_freq < policy->min) {
|
|
requested_freq = policy->cur;
|
|
dbs_info->requested_freq = requested_freq;
|
|
}
|
|
|
|
freq_step = get_freq_step(cs_tuners, policy);
|
|
|
|
/*
|
|
* Decrease requested_freq one freq_step for each idle period that
|
|
* we didn't update the frequency.
|
|
*/
|
|
if (policy_dbs->idle_periods < UINT_MAX) {
|
|
unsigned int freq_steps = policy_dbs->idle_periods * freq_step;
|
|
|
|
if (requested_freq > policy->min + freq_steps)
|
|
requested_freq -= freq_steps;
|
|
else
|
|
requested_freq = policy->min;
|
|
|
|
policy_dbs->idle_periods = UINT_MAX;
|
|
}
|
|
|
|
/* Check for frequency increase */
|
|
if (load > dbs_data->up_threshold) {
|
|
dbs_info->down_skip = 0;
|
|
|
|
/* if we are already at full speed then break out early */
|
|
if (requested_freq == policy->max)
|
|
goto out;
|
|
|
|
requested_freq += freq_step;
|
|
if (requested_freq > policy->max)
|
|
requested_freq = policy->max;
|
|
|
|
__cpufreq_driver_target(policy, requested_freq, CPUFREQ_RELATION_H);
|
|
dbs_info->requested_freq = requested_freq;
|
|
goto out;
|
|
}
|
|
|
|
/* if sampling_down_factor is active break out early */
|
|
if (++dbs_info->down_skip < dbs_data->sampling_down_factor)
|
|
goto out;
|
|
dbs_info->down_skip = 0;
|
|
|
|
/* Check for frequency decrease */
|
|
if (load < cs_tuners->down_threshold) {
|
|
/*
|
|
* if we cannot reduce the frequency anymore, break out early
|
|
*/
|
|
if (requested_freq == policy->min)
|
|
goto out;
|
|
|
|
if (requested_freq > freq_step)
|
|
requested_freq -= freq_step;
|
|
else
|
|
requested_freq = policy->min;
|
|
|
|
__cpufreq_driver_target(policy, requested_freq, CPUFREQ_RELATION_L);
|
|
dbs_info->requested_freq = requested_freq;
|
|
}
|
|
|
|
out:
|
|
return dbs_data->sampling_rate;
|
|
}
|
|
|
|
/************************** sysfs interface ************************/
|
|
|
|
static ssize_t store_sampling_down_factor(struct gov_attr_set *attr_set,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct dbs_data *dbs_data = to_dbs_data(attr_set);
|
|
unsigned int input;
|
|
int ret;
|
|
ret = sscanf(buf, "%u", &input);
|
|
|
|
if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
|
|
return -EINVAL;
|
|
|
|
dbs_data->sampling_down_factor = input;
|
|
return count;
|
|
}
|
|
|
|
static ssize_t store_up_threshold(struct gov_attr_set *attr_set,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct dbs_data *dbs_data = to_dbs_data(attr_set);
|
|
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
|
|
unsigned int input;
|
|
int ret;
|
|
ret = sscanf(buf, "%u", &input);
|
|
|
|
if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold)
|
|
return -EINVAL;
|
|
|
|
dbs_data->up_threshold = input;
|
|
return count;
|
|
}
|
|
|
|
static ssize_t store_down_threshold(struct gov_attr_set *attr_set,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct dbs_data *dbs_data = to_dbs_data(attr_set);
|
|
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
|
|
unsigned int input;
|
|
int ret;
|
|
ret = sscanf(buf, "%u", &input);
|
|
|
|
/* cannot be lower than 1 otherwise freq will not fall */
|
|
if (ret != 1 || input < 1 || input > 100 ||
|
|
input >= dbs_data->up_threshold)
|
|
return -EINVAL;
|
|
|
|
cs_tuners->down_threshold = input;
|
|
return count;
|
|
}
|
|
|
|
static ssize_t store_ignore_nice_load(struct gov_attr_set *attr_set,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct dbs_data *dbs_data = to_dbs_data(attr_set);
|
|
unsigned int input;
|
|
int ret;
|
|
|
|
ret = sscanf(buf, "%u", &input);
|
|
if (ret != 1)
|
|
return -EINVAL;
|
|
|
|
if (input > 1)
|
|
input = 1;
|
|
|
|
if (input == dbs_data->ignore_nice_load) /* nothing to do */
|
|
return count;
|
|
|
|
dbs_data->ignore_nice_load = input;
|
|
|
|
/* we need to re-evaluate prev_cpu_idle */
|
|
gov_update_cpu_data(dbs_data);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t store_freq_step(struct gov_attr_set *attr_set, const char *buf,
|
|
size_t count)
|
|
{
|
|
struct dbs_data *dbs_data = to_dbs_data(attr_set);
|
|
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
|
|
unsigned int input;
|
|
int ret;
|
|
ret = sscanf(buf, "%u", &input);
|
|
|
|
if (ret != 1)
|
|
return -EINVAL;
|
|
|
|
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 :)
|
|
*/
|
|
cs_tuners->freq_step = input;
|
|
return count;
|
|
}
|
|
|
|
gov_show_one_common(sampling_rate);
|
|
gov_show_one_common(sampling_down_factor);
|
|
gov_show_one_common(up_threshold);
|
|
gov_show_one_common(ignore_nice_load);
|
|
gov_show_one(cs, down_threshold);
|
|
gov_show_one(cs, freq_step);
|
|
|
|
gov_attr_rw(sampling_rate);
|
|
gov_attr_rw(sampling_down_factor);
|
|
gov_attr_rw(up_threshold);
|
|
gov_attr_rw(ignore_nice_load);
|
|
gov_attr_rw(down_threshold);
|
|
gov_attr_rw(freq_step);
|
|
|
|
static struct attribute *cs_attributes[] = {
|
|
&sampling_rate.attr,
|
|
&sampling_down_factor.attr,
|
|
&up_threshold.attr,
|
|
&down_threshold.attr,
|
|
&ignore_nice_load.attr,
|
|
&freq_step.attr,
|
|
NULL
|
|
};
|
|
|
|
/************************** sysfs end ************************/
|
|
|
|
static struct policy_dbs_info *cs_alloc(void)
|
|
{
|
|
struct cs_policy_dbs_info *dbs_info;
|
|
|
|
dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
|
|
return dbs_info ? &dbs_info->policy_dbs : NULL;
|
|
}
|
|
|
|
static void cs_free(struct policy_dbs_info *policy_dbs)
|
|
{
|
|
kfree(to_dbs_info(policy_dbs));
|
|
}
|
|
|
|
static int cs_init(struct dbs_data *dbs_data)
|
|
{
|
|
struct cs_dbs_tuners *tuners;
|
|
|
|
tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
|
|
if (!tuners)
|
|
return -ENOMEM;
|
|
|
|
tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
|
|
tuners->freq_step = DEF_FREQUENCY_STEP;
|
|
dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
|
|
dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
|
|
dbs_data->ignore_nice_load = 0;
|
|
dbs_data->tuners = tuners;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cs_exit(struct dbs_data *dbs_data)
|
|
{
|
|
kfree(dbs_data->tuners);
|
|
}
|
|
|
|
static void cs_start(struct cpufreq_policy *policy)
|
|
{
|
|
struct cs_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
|
|
|
|
dbs_info->down_skip = 0;
|
|
dbs_info->requested_freq = policy->cur;
|
|
}
|
|
|
|
static struct dbs_governor cs_governor = {
|
|
.gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("conservative"),
|
|
.kobj_type = { .default_attrs = cs_attributes },
|
|
.gov_dbs_update = cs_dbs_update,
|
|
.alloc = cs_alloc,
|
|
.free = cs_free,
|
|
.init = cs_init,
|
|
.exit = cs_exit,
|
|
.start = cs_start,
|
|
};
|
|
|
|
#define CPU_FREQ_GOV_CONSERVATIVE (cs_governor.gov)
|
|
|
|
MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
|
|
MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
|
|
"Low Latency Frequency Transition capable processors "
|
|
"optimised for use in a battery environment");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
|
|
struct cpufreq_governor *cpufreq_default_governor(void)
|
|
{
|
|
return &CPU_FREQ_GOV_CONSERVATIVE;
|
|
}
|
|
#endif
|
|
|
|
cpufreq_governor_init(CPU_FREQ_GOV_CONSERVATIVE);
|
|
cpufreq_governor_exit(CPU_FREQ_GOV_CONSERVATIVE);
|