![Stratos Karafotis](/assets/img/avatar_default.png)
Use an inline function to evaluate freq_target to avoid duplicate code. Also, define a macro for the default frequency step. Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
417 lines
11 KiB
C
417 lines
11 KiB
C
/*
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* drivers/cpufreq/cpufreq_conservative.c
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*
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* Copyright (C) 2001 Russell King
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* (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
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* Jun Nakajima <jun.nakajima@intel.com>
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* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/cpufreq.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/kernel_stat.h>
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#include <linux/kobject.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/notifier.h>
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#include <linux/percpu-defs.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include <linux/types.h>
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#include "cpufreq_governor.h"
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/* Conservative governor macros */
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#define DEF_FREQUENCY_UP_THRESHOLD (80)
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#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
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#define DEF_FREQUENCY_STEP (5)
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#define DEF_SAMPLING_DOWN_FACTOR (1)
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#define MAX_SAMPLING_DOWN_FACTOR (10)
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static DEFINE_PER_CPU(struct cs_cpu_dbs_info_s, cs_cpu_dbs_info);
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static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
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struct cpufreq_policy *policy)
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{
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unsigned int freq_target = (cs_tuners->freq_step * policy->max) / 100;
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/* max freq cannot be less than 100. But who knows... */
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if (unlikely(freq_target == 0))
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freq_target = DEF_FREQUENCY_STEP;
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return freq_target;
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}
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/*
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* Every sampling_rate, we check, if current idle time is less than 20%
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* (default), then we try to increase frequency. Every sampling_rate *
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* sampling_down_factor, we check, if current idle time is more than 80%
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* (default), then we try to decrease frequency
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*
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* Any frequency increase takes it to the maximum frequency. Frequency reduction
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* happens at minimum steps of 5% (default) of maximum frequency
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*/
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static void cs_check_cpu(int cpu, unsigned int load)
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{
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struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
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struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy;
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struct dbs_data *dbs_data = policy->governor_data;
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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/*
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* break out if we 'cannot' reduce the speed as the user might
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* want freq_step to be zero
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*/
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if (cs_tuners->freq_step == 0)
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return;
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/* Check for frequency increase */
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if (load > cs_tuners->up_threshold) {
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dbs_info->down_skip = 0;
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/* if we are already at full speed then break out early */
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if (dbs_info->requested_freq == policy->max)
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return;
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dbs_info->requested_freq += get_freq_target(cs_tuners, policy);
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if (dbs_info->requested_freq > policy->max)
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dbs_info->requested_freq = policy->max;
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__cpufreq_driver_target(policy, dbs_info->requested_freq,
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CPUFREQ_RELATION_H);
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return;
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}
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/* if sampling_down_factor is active break out early */
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if (++dbs_info->down_skip < cs_tuners->sampling_down_factor)
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return;
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dbs_info->down_skip = 0;
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/* Check for frequency decrease */
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if (load < cs_tuners->down_threshold) {
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/*
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* if we cannot reduce the frequency anymore, break out early
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*/
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if (policy->cur == policy->min)
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return;
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dbs_info->requested_freq -= get_freq_target(cs_tuners, policy);
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if (dbs_info->requested_freq < policy->min)
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dbs_info->requested_freq = policy->min;
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__cpufreq_driver_target(policy, dbs_info->requested_freq,
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CPUFREQ_RELATION_L);
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return;
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}
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}
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static void cs_dbs_timer(struct work_struct *work)
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{
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struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
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struct cs_cpu_dbs_info_s, cdbs.work.work);
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unsigned int cpu = dbs_info->cdbs.cur_policy->cpu;
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struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
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cpu);
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struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data;
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
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bool modify_all = true;
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mutex_lock(&core_dbs_info->cdbs.timer_mutex);
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if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
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modify_all = false;
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else
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dbs_check_cpu(dbs_data, cpu);
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gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all);
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mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
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}
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static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
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void *data)
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{
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struct cpufreq_freqs *freq = data;
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struct cs_cpu_dbs_info_s *dbs_info =
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&per_cpu(cs_cpu_dbs_info, freq->cpu);
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struct cpufreq_policy *policy;
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if (!dbs_info->enable)
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return 0;
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policy = dbs_info->cdbs.cur_policy;
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/*
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* we only care if our internally tracked freq moves outside the 'valid'
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* ranges of frequency available to us otherwise we do not change it
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*/
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if (dbs_info->requested_freq > policy->max
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|| dbs_info->requested_freq < policy->min)
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dbs_info->requested_freq = freq->new;
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return 0;
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}
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/************************** sysfs interface ************************/
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static struct common_dbs_data cs_dbs_cdata;
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static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data,
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const char *buf, size_t count)
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{
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
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return -EINVAL;
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cs_tuners->sampling_down_factor = input;
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return count;
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}
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static ssize_t store_sampling_rate(struct dbs_data *dbs_data, const char *buf,
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size_t count)
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{
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1)
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return -EINVAL;
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cs_tuners->sampling_rate = max(input, dbs_data->min_sampling_rate);
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return count;
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}
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static ssize_t store_up_threshold(struct dbs_data *dbs_data, const char *buf,
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size_t count)
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{
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1 || input > 100 || input <= cs_tuners->down_threshold)
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return -EINVAL;
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cs_tuners->up_threshold = input;
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return count;
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}
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static ssize_t store_down_threshold(struct dbs_data *dbs_data, const char *buf,
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size_t count)
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{
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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/* cannot be lower than 11 otherwise freq will not fall */
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if (ret != 1 || input < 11 || input > 100 ||
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input >= cs_tuners->up_threshold)
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return -EINVAL;
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cs_tuners->down_threshold = input;
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return count;
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}
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static ssize_t store_ignore_nice(struct dbs_data *dbs_data, const char *buf,
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size_t count)
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{
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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unsigned int input, j;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1)
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return -EINVAL;
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if (input > 1)
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input = 1;
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if (input == cs_tuners->ignore_nice) /* nothing to do */
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return count;
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cs_tuners->ignore_nice = input;
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/* we need to re-evaluate prev_cpu_idle */
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for_each_online_cpu(j) {
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struct cs_cpu_dbs_info_s *dbs_info;
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dbs_info = &per_cpu(cs_cpu_dbs_info, j);
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dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j,
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&dbs_info->cdbs.prev_cpu_wall, 0);
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if (cs_tuners->ignore_nice)
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dbs_info->cdbs.prev_cpu_nice =
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kcpustat_cpu(j).cpustat[CPUTIME_NICE];
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}
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return count;
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}
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static ssize_t store_freq_step(struct dbs_data *dbs_data, const char *buf,
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size_t count)
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{
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struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
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unsigned int input;
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int ret;
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ret = sscanf(buf, "%u", &input);
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if (ret != 1)
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return -EINVAL;
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if (input > 100)
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input = 100;
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/*
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* no need to test here if freq_step is zero as the user might actually
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* want this, they would be crazy though :)
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*/
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cs_tuners->freq_step = input;
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return count;
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}
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show_store_one(cs, sampling_rate);
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show_store_one(cs, sampling_down_factor);
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show_store_one(cs, up_threshold);
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show_store_one(cs, down_threshold);
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show_store_one(cs, ignore_nice);
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show_store_one(cs, freq_step);
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declare_show_sampling_rate_min(cs);
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gov_sys_pol_attr_rw(sampling_rate);
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gov_sys_pol_attr_rw(sampling_down_factor);
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gov_sys_pol_attr_rw(up_threshold);
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gov_sys_pol_attr_rw(down_threshold);
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gov_sys_pol_attr_rw(ignore_nice);
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gov_sys_pol_attr_rw(freq_step);
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gov_sys_pol_attr_ro(sampling_rate_min);
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static struct attribute *dbs_attributes_gov_sys[] = {
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&sampling_rate_min_gov_sys.attr,
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&sampling_rate_gov_sys.attr,
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&sampling_down_factor_gov_sys.attr,
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&up_threshold_gov_sys.attr,
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&down_threshold_gov_sys.attr,
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&ignore_nice_gov_sys.attr,
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&freq_step_gov_sys.attr,
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NULL
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};
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static struct attribute_group cs_attr_group_gov_sys = {
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.attrs = dbs_attributes_gov_sys,
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.name = "conservative",
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};
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static struct attribute *dbs_attributes_gov_pol[] = {
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&sampling_rate_min_gov_pol.attr,
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&sampling_rate_gov_pol.attr,
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&sampling_down_factor_gov_pol.attr,
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&up_threshold_gov_pol.attr,
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&down_threshold_gov_pol.attr,
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&ignore_nice_gov_pol.attr,
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&freq_step_gov_pol.attr,
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NULL
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};
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static struct attribute_group cs_attr_group_gov_pol = {
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.attrs = dbs_attributes_gov_pol,
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.name = "conservative",
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};
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/************************** sysfs end ************************/
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static int cs_init(struct dbs_data *dbs_data)
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{
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struct cs_dbs_tuners *tuners;
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tuners = kzalloc(sizeof(struct cs_dbs_tuners), GFP_KERNEL);
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if (!tuners) {
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pr_err("%s: kzalloc failed\n", __func__);
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return -ENOMEM;
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}
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tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
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tuners->down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD;
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tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
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tuners->ignore_nice = 0;
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tuners->freq_step = DEF_FREQUENCY_STEP;
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dbs_data->tuners = tuners;
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dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
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jiffies_to_usecs(10);
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mutex_init(&dbs_data->mutex);
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return 0;
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}
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static void cs_exit(struct dbs_data *dbs_data)
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{
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kfree(dbs_data->tuners);
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}
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define_get_cpu_dbs_routines(cs_cpu_dbs_info);
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static struct notifier_block cs_cpufreq_notifier_block = {
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.notifier_call = dbs_cpufreq_notifier,
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};
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static struct cs_ops cs_ops = {
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.notifier_block = &cs_cpufreq_notifier_block,
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};
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static struct common_dbs_data cs_dbs_cdata = {
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.governor = GOV_CONSERVATIVE,
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.attr_group_gov_sys = &cs_attr_group_gov_sys,
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.attr_group_gov_pol = &cs_attr_group_gov_pol,
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.get_cpu_cdbs = get_cpu_cdbs,
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.get_cpu_dbs_info_s = get_cpu_dbs_info_s,
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.gov_dbs_timer = cs_dbs_timer,
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.gov_check_cpu = cs_check_cpu,
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.gov_ops = &cs_ops,
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.init = cs_init,
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.exit = cs_exit,
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};
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static int cs_cpufreq_governor_dbs(struct cpufreq_policy *policy,
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unsigned int event)
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{
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return cpufreq_governor_dbs(policy, &cs_dbs_cdata, event);
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}
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#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
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static
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#endif
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struct cpufreq_governor cpufreq_gov_conservative = {
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.name = "conservative",
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.governor = cs_cpufreq_governor_dbs,
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.max_transition_latency = TRANSITION_LATENCY_LIMIT,
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.owner = THIS_MODULE,
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};
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static int __init cpufreq_gov_dbs_init(void)
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{
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return cpufreq_register_governor(&cpufreq_gov_conservative);
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}
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static void __exit cpufreq_gov_dbs_exit(void)
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{
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cpufreq_unregister_governor(&cpufreq_gov_conservative);
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}
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MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
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MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
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"Low Latency Frequency Transition capable processors "
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"optimised for use in a battery environment");
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MODULE_LICENSE("GPL");
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#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
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fs_initcall(cpufreq_gov_dbs_init);
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#else
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module_init(cpufreq_gov_dbs_init);
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#endif
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module_exit(cpufreq_gov_dbs_exit);
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