2005-05-31 20:03:47 -06:00
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/*
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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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2009-02-13 12:01:01 -07:00
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* (C) 2009 Alexander Clouter <alex@digriz.org.uk>
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2005-05-31 20:03:47 -06:00
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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/kernel.h>
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#include <linux/module.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/ctype.h>
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#include <linux/cpufreq.h>
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#include <linux/sysctl.h>
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#include <linux/types.h>
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#include <linux/fs.h>
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#include <linux/sysfs.h>
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2006-06-23 04:31:19 -06:00
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#include <linux/cpu.h>
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2005-05-31 20:03:47 -06:00
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#include <linux/kmod.h>
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#include <linux/workqueue.h>
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#include <linux/jiffies.h>
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#include <linux/kernel_stat.h>
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#include <linux/percpu.h>
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2006-01-13 16:54:22 -07:00
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#include <linux/mutex.h>
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2005-05-31 20:03:47 -06:00
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/*
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* dbs is used in this file as a shortform for demandbased switching
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* It helps to keep variable names smaller, simpler
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*/
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#define DEF_FREQUENCY_UP_THRESHOLD (80)
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#define DEF_FREQUENCY_DOWN_THRESHOLD (20)
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2007-10-22 14:49:09 -06:00
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/*
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* The polling frequency of this governor depends on the capability of
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2005-05-31 20:03:47 -06:00
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* the processor. Default polling frequency is 1000 times the transition
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2007-10-22 14:49:09 -06:00
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* latency of the processor. The governor will work on any processor with
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* transition latency <= 10mS, using appropriate sampling
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2005-05-31 20:03:47 -06:00
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* rate.
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2006-10-26 04:50:58 -06:00
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* For CPUs with transition latency > 10mS (mostly drivers
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* with CPUFREQ_ETERNAL), this governor will not work.
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2005-05-31 20:03:47 -06:00
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* All times here are in uS.
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*/
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2007-10-22 14:49:09 -06:00
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static unsigned int def_sampling_rate;
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2006-03-22 02:54:10 -07:00
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#define MIN_SAMPLING_RATE_RATIO (2)
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/* for correct statistics, we need at least 10 ticks between each measure */
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2006-10-26 04:50:58 -06:00
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#define MIN_STAT_SAMPLING_RATE \
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(MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10))
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#define MIN_SAMPLING_RATE \
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(def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
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2009-02-04 03:55:12 -07:00
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/* Above MIN_SAMPLING_RATE will vanish with its sysfs file soon
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* Define the minimal settable sampling rate to the greater of:
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* - "HW transition latency" * 100 (same as default sampling / 10)
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* - MIN_STAT_SAMPLING_RATE
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* To avoid that userspace shoots itself.
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*/
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static unsigned int minimum_sampling_rate(void)
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{
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return max(def_sampling_rate / 10, MIN_STAT_SAMPLING_RATE);
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}
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/* This will also vanish soon with removing sampling_rate_max */
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2005-05-31 20:03:47 -06:00
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#define MAX_SAMPLING_RATE (500 * def_sampling_rate)
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2009-02-04 03:55:12 -07:00
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#define LATENCY_MULTIPLIER (1000)
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2006-03-22 02:54:10 -07:00
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#define DEF_SAMPLING_DOWN_FACTOR (1)
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#define MAX_SAMPLING_DOWN_FACTOR (10)
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2007-10-02 14:28:12 -06:00
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#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
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2005-05-31 20:03:47 -06:00
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2006-11-22 07:57:56 -07:00
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static void do_dbs_timer(struct work_struct *work);
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2005-05-31 20:03:47 -06:00
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struct cpu_dbs_info_s {
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2007-10-22 14:49:09 -06:00
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struct cpufreq_policy *cur_policy;
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unsigned int prev_cpu_idle_up;
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unsigned int prev_cpu_idle_down;
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unsigned int enable;
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unsigned int down_skip;
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unsigned int requested_freq;
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2005-05-31 20:03:47 -06:00
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};
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static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
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static unsigned int dbs_enable; /* number of CPUs using this policy */
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2006-06-21 16:18:34 -06:00
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/*
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* DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
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* lock and dbs_mutex. cpu_hotplug lock should always be held before
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* dbs_mutex. If any function that can potentially take cpu_hotplug lock
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* (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
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* cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
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* is recursive for the same process. -Venki
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*/
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2009-01-17 23:39:51 -07:00
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static DEFINE_MUTEX(dbs_mutex);
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2006-11-22 07:57:56 -07:00
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static DECLARE_DELAYED_WORK(dbs_work, do_dbs_timer);
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2005-05-31 20:03:47 -06:00
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struct dbs_tuners {
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2007-10-22 14:49:09 -06:00
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unsigned int sampling_rate;
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unsigned int sampling_down_factor;
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unsigned int up_threshold;
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unsigned int down_threshold;
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unsigned int ignore_nice;
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unsigned int freq_step;
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2005-05-31 20:03:47 -06:00
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};
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static struct dbs_tuners dbs_tuners_ins = {
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2007-10-22 14:49:09 -06:00
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.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
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.down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
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.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
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.ignore_nice = 0,
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.freq_step = 5,
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2005-05-31 20:03:47 -06:00
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};
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2005-05-31 20:03:49 -06:00
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static inline unsigned int get_cpu_idle_time(unsigned int cpu)
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{
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2006-10-26 04:50:58 -06:00
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unsigned int add_nice = 0, ret;
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if (dbs_tuners_ins.ignore_nice)
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add_nice = kstat_cpu(cpu).cpustat.nice;
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2007-10-22 14:49:09 -06:00
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ret = kstat_cpu(cpu).cpustat.idle +
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2005-05-31 20:03:49 -06:00
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kstat_cpu(cpu).cpustat.iowait +
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2006-10-26 04:50:58 -06:00
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add_nice;
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return ret;
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2005-05-31 20:03:49 -06:00
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}
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2007-10-22 01:50:13 -06:00
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/* keep track of frequency transitions */
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static int
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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 cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info,
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freq->cpu);
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if (!this_dbs_info->enable)
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return 0;
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this_dbs_info->requested_freq = freq->new;
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return 0;
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}
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static struct notifier_block dbs_cpufreq_notifier_block = {
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.notifier_call = dbs_cpufreq_notifier
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};
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2005-05-31 20:03:47 -06:00
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/************************** sysfs interface ************************/
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static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
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{
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2009-02-04 03:54:04 -07:00
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static int print_once;
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if (!print_once) {
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printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
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"sysfs file is deprecated - used by: %s\n",
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current->comm);
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print_once = 1;
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}
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2009-01-17 23:39:51 -07:00
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return sprintf(buf, "%u\n", MAX_SAMPLING_RATE);
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2005-05-31 20:03:47 -06:00
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}
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static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
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{
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2009-02-04 03:54:04 -07:00
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static int print_once;
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if (!print_once) {
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printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
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"sysfs file is deprecated - used by: %s\n", current->comm);
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print_once = 1;
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}
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2009-01-17 23:39:51 -07:00
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return sprintf(buf, "%u\n", MIN_SAMPLING_RATE);
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2005-05-31 20:03:47 -06:00
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}
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2007-10-22 14:49:09 -06:00
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#define define_one_ro(_name) \
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static struct freq_attr _name = \
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2005-05-31 20:03:47 -06:00
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__ATTR(_name, 0444, show_##_name, NULL)
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define_one_ro(sampling_rate_max);
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define_one_ro(sampling_rate_min);
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/* cpufreq_conservative Governor Tunables */
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#define show_one(file_name, object) \
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static ssize_t show_##file_name \
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(struct cpufreq_policy *unused, char *buf) \
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{ \
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return sprintf(buf, "%u\n", dbs_tuners_ins.object); \
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}
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show_one(sampling_rate, sampling_rate);
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show_one(sampling_down_factor, sampling_down_factor);
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show_one(up_threshold, up_threshold);
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show_one(down_threshold, down_threshold);
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2005-12-01 02:09:25 -07:00
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show_one(ignore_nice_load, ignore_nice);
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2005-05-31 20:03:47 -06:00
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show_one(freq_step, freq_step);
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2007-10-22 14:49:09 -06:00
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static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused,
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2005-05-31 20:03:47 -06:00
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const char *buf, size_t count)
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{
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unsigned int input;
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int ret;
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2009-01-17 23:39:51 -07:00
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ret = sscanf(buf, "%u", &input);
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2006-03-22 02:54:10 -07:00
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if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
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2005-05-31 20:03:47 -06:00
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return -EINVAL;
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2006-01-13 16:54:22 -07:00
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mutex_lock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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dbs_tuners_ins.sampling_down_factor = input;
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return count;
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}
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2007-10-22 14:49:09 -06:00
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static ssize_t store_sampling_rate(struct cpufreq_policy *unused,
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2005-05-31 20:03:47 -06:00
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const char *buf, size_t count)
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{
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unsigned int input;
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int ret;
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2009-01-17 23:39:51 -07:00
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ret = sscanf(buf, "%u", &input);
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2005-05-31 20:03:47 -06:00
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2006-01-13 16:54:22 -07:00
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mutex_lock(&dbs_mutex);
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2009-02-04 03:55:12 -07:00
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if (ret != 1) {
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return -EINVAL;
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}
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2009-02-04 03:55:12 -07:00
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dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate());
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return count;
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}
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2007-10-22 14:49:09 -06:00
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static ssize_t store_up_threshold(struct cpufreq_policy *unused,
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2005-05-31 20:03:47 -06:00
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const char *buf, size_t count)
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{
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unsigned int input;
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int ret;
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2009-01-17 23:39:51 -07:00
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ret = sscanf(buf, "%u", &input);
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2005-05-31 20:03:47 -06:00
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2006-01-13 16:54:22 -07:00
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mutex_lock(&dbs_mutex);
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2009-01-17 23:39:51 -07:00
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if (ret != 1 || input > 100 ||
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input <= dbs_tuners_ins.down_threshold) {
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return -EINVAL;
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}
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dbs_tuners_ins.up_threshold = input;
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return count;
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}
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2007-10-22 14:49:09 -06:00
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static ssize_t store_down_threshold(struct cpufreq_policy *unused,
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2005-05-31 20:03:47 -06:00
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const char *buf, size_t count)
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{
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unsigned int input;
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int ret;
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2009-01-17 23:39:51 -07:00
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ret = sscanf(buf, "%u", &input);
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2005-05-31 20:03:47 -06:00
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2006-01-13 16:54:22 -07:00
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mutex_lock(&dbs_mutex);
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2006-04-01 20:07:07 -07:00
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if (ret != 1 || input > 100 || input >= dbs_tuners_ins.up_threshold) {
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return -EINVAL;
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}
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dbs_tuners_ins.down_threshold = input;
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return count;
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}
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2005-12-01 02:09:25 -07:00
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static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
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2005-05-31 20:03:47 -06:00
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const char *buf, size_t count)
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{
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unsigned int input;
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int ret;
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unsigned int j;
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2007-10-22 14:49:09 -06:00
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ret = sscanf(buf, "%u", &input);
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if (ret != 1)
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2005-05-31 20:03:47 -06:00
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return -EINVAL;
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2007-10-22 14:49:09 -06:00
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if (input > 1)
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2005-05-31 20:03:47 -06:00
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input = 1;
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2007-10-22 14:49:09 -06:00
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2006-01-13 16:54:22 -07:00
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mutex_lock(&dbs_mutex);
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2007-10-22 14:49:09 -06:00
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if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
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2006-01-13 16:54:22 -07:00
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mutex_unlock(&dbs_mutex);
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2005-05-31 20:03:47 -06:00
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return count;
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}
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dbs_tuners_ins.ignore_nice = input;
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/* we need to re-evaluate prev_cpu_idle_up and prev_cpu_idle_down */
|
2005-05-31 20:03:49 -06:00
|
|
|
for_each_online_cpu(j) {
|
2005-05-31 20:03:47 -06:00
|
|
|
struct cpu_dbs_info_s *j_dbs_info;
|
|
|
|
j_dbs_info = &per_cpu(cpu_dbs_info, j);
|
2005-05-31 20:03:49 -06:00
|
|
|
j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j);
|
2005-05-31 20:03:47 -06:00
|
|
|
j_dbs_info->prev_cpu_idle_down = j_dbs_info->prev_cpu_idle_up;
|
|
|
|
}
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_unlock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
return count;
|
|
|
|
}
|
|
|
|
|
|
|
|
static ssize_t store_freq_step(struct cpufreq_policy *policy,
|
|
|
|
const char *buf, size_t count)
|
|
|
|
{
|
|
|
|
unsigned int input;
|
|
|
|
int ret;
|
|
|
|
|
2007-10-22 14:49:09 -06:00
|
|
|
ret = sscanf(buf, "%u", &input);
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2007-10-22 14:49:09 -06:00
|
|
|
if (ret != 1)
|
2005-05-31 20:03:47 -06:00
|
|
|
return -EINVAL;
|
|
|
|
|
2007-10-22 14:49:09 -06:00
|
|
|
if (input > 100)
|
2005-05-31 20:03:47 -06:00
|
|
|
input = 100;
|
2007-10-22 14:49:09 -06:00
|
|
|
|
2005-05-31 20:03:47 -06:00
|
|
|
/* no need to test here if freq_step is zero as the user might actually
|
|
|
|
* want this, they would be crazy though :) */
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_lock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
dbs_tuners_ins.freq_step = input;
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_unlock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
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(down_threshold);
|
2005-12-01 02:09:25 -07:00
|
|
|
define_one_rw(ignore_nice_load);
|
2005-05-31 20:03:47 -06:00
|
|
|
define_one_rw(freq_step);
|
|
|
|
|
2009-01-17 23:39:51 -07:00
|
|
|
static struct attribute *dbs_attributes[] = {
|
2005-05-31 20:03:47 -06:00
|
|
|
&sampling_rate_max.attr,
|
|
|
|
&sampling_rate_min.attr,
|
|
|
|
&sampling_rate.attr,
|
|
|
|
&sampling_down_factor.attr,
|
|
|
|
&up_threshold.attr,
|
|
|
|
&down_threshold.attr,
|
2005-12-01 02:09:25 -07:00
|
|
|
&ignore_nice_load.attr,
|
2005-05-31 20:03:47 -06:00
|
|
|
&freq_step.attr,
|
|
|
|
NULL
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct attribute_group dbs_attr_group = {
|
|
|
|
.attrs = dbs_attributes,
|
|
|
|
.name = "conservative",
|
|
|
|
};
|
|
|
|
|
|
|
|
/************************** sysfs end ************************/
|
|
|
|
|
|
|
|
static void dbs_check_cpu(int cpu)
|
|
|
|
{
|
|
|
|
unsigned int idle_ticks, up_idle_ticks, down_idle_ticks;
|
2006-03-22 02:59:16 -07:00
|
|
|
unsigned int tmp_idle_ticks, total_idle_ticks;
|
2008-07-30 10:59:56 -06:00
|
|
|
unsigned int freq_target;
|
2005-05-31 20:03:47 -06:00
|
|
|
unsigned int freq_down_sampling_rate;
|
2006-03-22 02:59:16 -07:00
|
|
|
struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
|
2005-05-31 20:03:47 -06:00
|
|
|
struct cpufreq_policy *policy;
|
|
|
|
|
|
|
|
if (!this_dbs_info->enable)
|
|
|
|
return;
|
|
|
|
|
2006-03-22 02:59:16 -07:00
|
|
|
policy = this_dbs_info->cur_policy;
|
|
|
|
|
2007-10-22 14:49:09 -06:00
|
|
|
/*
|
|
|
|
* The default safe range is 20% to 80%
|
2005-05-31 20:03:47 -06:00
|
|
|
* Every sampling_rate, we check
|
2007-10-22 14:49:09 -06:00
|
|
|
* - If current idle time is less than 20%, then we try to
|
|
|
|
* increase frequency
|
2005-05-31 20:03:47 -06:00
|
|
|
* Every sampling_rate*sampling_down_factor, we check
|
2007-10-22 14:49:09 -06:00
|
|
|
* - If current idle time is more than 80%, then we try to
|
|
|
|
* decrease frequency
|
2005-05-31 20:03:47 -06:00
|
|
|
*
|
2007-10-22 14:49:09 -06:00
|
|
|
* Any frequency increase takes it to the maximum frequency.
|
|
|
|
* Frequency reduction happens at minimum steps of
|
|
|
|
* 5% (default) of max_frequency
|
2005-05-31 20:03:47 -06:00
|
|
|
*/
|
|
|
|
|
|
|
|
/* Check for frequency increase */
|
2005-05-31 20:03:49 -06:00
|
|
|
idle_ticks = UINT_MAX;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2006-03-22 02:59:16 -07:00
|
|
|
/* Check for frequency increase */
|
|
|
|
total_idle_ticks = get_cpu_idle_time(cpu);
|
|
|
|
tmp_idle_ticks = total_idle_ticks -
|
|
|
|
this_dbs_info->prev_cpu_idle_up;
|
|
|
|
this_dbs_info->prev_cpu_idle_up = total_idle_ticks;
|
|
|
|
|
|
|
|
if (tmp_idle_ticks < idle_ticks)
|
|
|
|
idle_ticks = tmp_idle_ticks;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
/* Scale idle ticks by 100 and compare with up and down ticks */
|
|
|
|
idle_ticks *= 100;
|
|
|
|
up_idle_ticks = (100 - dbs_tuners_ins.up_threshold) *
|
2006-03-22 02:54:10 -07:00
|
|
|
usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
if (idle_ticks < up_idle_ticks) {
|
2006-03-22 03:00:18 -07:00
|
|
|
this_dbs_info->down_skip = 0;
|
2006-03-22 02:59:16 -07:00
|
|
|
this_dbs_info->prev_cpu_idle_down =
|
|
|
|
this_dbs_info->prev_cpu_idle_up;
|
2005-05-31 20:03:49 -06:00
|
|
|
|
2005-05-31 20:03:47 -06:00
|
|
|
/* if we are already at full speed then break out early */
|
2006-03-22 03:00:18 -07:00
|
|
|
if (this_dbs_info->requested_freq == policy->max)
|
2005-05-31 20:03:47 -06:00
|
|
|
return;
|
2007-10-22 14:49:09 -06:00
|
|
|
|
2008-07-30 10:59:56 -06:00
|
|
|
freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
/* max freq cannot be less than 100. But who knows.... */
|
2008-07-30 10:59:56 -06:00
|
|
|
if (unlikely(freq_target == 0))
|
|
|
|
freq_target = 5;
|
2007-10-22 14:49:09 -06:00
|
|
|
|
2008-07-30 10:59:56 -06:00
|
|
|
this_dbs_info->requested_freq += freq_target;
|
2006-03-22 03:00:18 -07:00
|
|
|
if (this_dbs_info->requested_freq > policy->max)
|
|
|
|
this_dbs_info->requested_freq = policy->max;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2006-03-22 03:00:18 -07:00
|
|
|
__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
|
2005-05-31 20:03:47 -06:00
|
|
|
CPUFREQ_RELATION_H);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Check for frequency decrease */
|
2006-03-22 03:00:18 -07:00
|
|
|
this_dbs_info->down_skip++;
|
|
|
|
if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor)
|
2005-05-31 20:03:47 -06:00
|
|
|
return;
|
|
|
|
|
2006-03-22 02:59:16 -07:00
|
|
|
/* Check for frequency decrease */
|
|
|
|
total_idle_ticks = this_dbs_info->prev_cpu_idle_up;
|
|
|
|
tmp_idle_ticks = total_idle_ticks -
|
|
|
|
this_dbs_info->prev_cpu_idle_down;
|
|
|
|
this_dbs_info->prev_cpu_idle_down = total_idle_ticks;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2006-03-22 02:59:16 -07:00
|
|
|
if (tmp_idle_ticks < idle_ticks)
|
|
|
|
idle_ticks = tmp_idle_ticks;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
/* Scale idle ticks by 100 and compare with up and down ticks */
|
|
|
|
idle_ticks *= 100;
|
2006-03-22 03:00:18 -07:00
|
|
|
this_dbs_info->down_skip = 0;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
freq_down_sampling_rate = dbs_tuners_ins.sampling_rate *
|
|
|
|
dbs_tuners_ins.sampling_down_factor;
|
|
|
|
down_idle_ticks = (100 - dbs_tuners_ins.down_threshold) *
|
2006-03-22 02:54:10 -07:00
|
|
|
usecs_to_jiffies(freq_down_sampling_rate);
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2005-05-31 20:03:49 -06:00
|
|
|
if (idle_ticks > down_idle_ticks) {
|
2006-03-22 02:54:10 -07:00
|
|
|
/*
|
|
|
|
* if we are already at the lowest speed then break out early
|
2005-05-31 20:03:47 -06:00
|
|
|
* or if we 'cannot' reduce the speed as the user might want
|
2008-07-30 10:59:56 -06:00
|
|
|
* freq_target to be zero
|
2006-03-22 02:54:10 -07:00
|
|
|
*/
|
2006-03-22 03:00:18 -07:00
|
|
|
if (this_dbs_info->requested_freq == policy->min
|
2005-05-31 20:03:47 -06:00
|
|
|
|| dbs_tuners_ins.freq_step == 0)
|
|
|
|
return;
|
|
|
|
|
2008-07-30 10:59:56 -06:00
|
|
|
freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
/* max freq cannot be less than 100. But who knows.... */
|
2008-07-30 10:59:56 -06:00
|
|
|
if (unlikely(freq_target == 0))
|
|
|
|
freq_target = 5;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2008-07-30 10:59:56 -06:00
|
|
|
this_dbs_info->requested_freq -= freq_target;
|
2006-03-22 03:00:18 -07:00
|
|
|
if (this_dbs_info->requested_freq < policy->min)
|
|
|
|
this_dbs_info->requested_freq = policy->min;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2006-03-22 03:00:18 -07:00
|
|
|
__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
|
2006-03-22 02:54:10 -07:00
|
|
|
CPUFREQ_RELATION_H);
|
2005-05-31 20:03:47 -06:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2006-11-22 07:57:56 -07:00
|
|
|
static void do_dbs_timer(struct work_struct *work)
|
2007-10-22 14:49:09 -06:00
|
|
|
{
|
2005-05-31 20:03:47 -06:00
|
|
|
int i;
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_lock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
for_each_online_cpu(i)
|
|
|
|
dbs_check_cpu(i);
|
2007-10-22 14:49:09 -06:00
|
|
|
schedule_delayed_work(&dbs_work,
|
2005-05-31 20:03:47 -06:00
|
|
|
usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_unlock(&dbs_mutex);
|
2007-10-22 14:49:09 -06:00
|
|
|
}
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
static inline void dbs_timer_init(void)
|
|
|
|
{
|
2008-07-07 11:16:20 -06:00
|
|
|
init_timer_deferrable(&dbs_work.timer);
|
2005-05-31 20:03:47 -06:00
|
|
|
schedule_delayed_work(&dbs_work,
|
|
|
|
usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void dbs_timer_exit(void)
|
|
|
|
{
|
|
|
|
cancel_delayed_work(&dbs_work);
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
|
|
|
|
unsigned int event)
|
|
|
|
{
|
|
|
|
unsigned int cpu = policy->cpu;
|
|
|
|
struct cpu_dbs_info_s *this_dbs_info;
|
|
|
|
unsigned int j;
|
2006-10-20 15:31:00 -06:00
|
|
|
int rc;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
|
|
|
|
|
|
|
|
switch (event) {
|
|
|
|
case CPUFREQ_GOV_START:
|
2007-10-22 14:49:09 -06:00
|
|
|
if ((!cpu_online(cpu)) || (!policy->cur))
|
2005-05-31 20:03:47 -06:00
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
if (this_dbs_info->enable) /* Already enabled */
|
|
|
|
break;
|
2007-10-22 14:49:09 -06:00
|
|
|
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_lock(&dbs_mutex);
|
2006-10-20 15:31:00 -06:00
|
|
|
|
|
|
|
rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
|
|
|
|
if (rc) {
|
|
|
|
mutex_unlock(&dbs_mutex);
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
|
2009-01-04 06:18:06 -07:00
|
|
|
for_each_cpu(j, policy->cpus) {
|
2005-05-31 20:03:47 -06:00
|
|
|
struct cpu_dbs_info_s *j_dbs_info;
|
|
|
|
j_dbs_info = &per_cpu(cpu_dbs_info, j);
|
|
|
|
j_dbs_info->cur_policy = policy;
|
2007-10-22 14:49:09 -06:00
|
|
|
|
2006-03-22 02:59:16 -07:00
|
|
|
j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(cpu);
|
2005-05-31 20:03:47 -06:00
|
|
|
j_dbs_info->prev_cpu_idle_down
|
|
|
|
= j_dbs_info->prev_cpu_idle_up;
|
|
|
|
}
|
|
|
|
this_dbs_info->enable = 1;
|
2006-03-22 03:00:18 -07:00
|
|
|
this_dbs_info->down_skip = 0;
|
|
|
|
this_dbs_info->requested_freq = policy->cur;
|
2006-10-20 15:31:00 -06:00
|
|
|
|
2005-05-31 20:03:47 -06:00
|
|
|
dbs_enable++;
|
|
|
|
/*
|
|
|
|
* Start the timerschedule work, when this governor
|
|
|
|
* is used for first time
|
|
|
|
*/
|
|
|
|
if (dbs_enable == 1) {
|
|
|
|
unsigned int latency;
|
|
|
|
/* policy latency is in nS. Convert it to uS first */
|
2006-03-22 02:54:10 -07:00
|
|
|
latency = policy->cpuinfo.transition_latency / 1000;
|
|
|
|
if (latency == 0)
|
|
|
|
latency = 1;
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2009-02-04 03:55:12 -07:00
|
|
|
def_sampling_rate =
|
|
|
|
max(10 * latency * LATENCY_MULTIPLIER,
|
|
|
|
MIN_STAT_SAMPLING_RATE);
|
2006-03-22 02:54:10 -07:00
|
|
|
|
2005-05-31 20:03:47 -06:00
|
|
|
dbs_tuners_ins.sampling_rate = def_sampling_rate;
|
|
|
|
|
|
|
|
dbs_timer_init();
|
2007-10-22 01:50:13 -06:00
|
|
|
cpufreq_register_notifier(
|
|
|
|
&dbs_cpufreq_notifier_block,
|
|
|
|
CPUFREQ_TRANSITION_NOTIFIER);
|
2005-05-31 20:03:47 -06:00
|
|
|
}
|
2007-10-22 14:49:09 -06:00
|
|
|
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_unlock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
break;
|
|
|
|
|
|
|
|
case CPUFREQ_GOV_STOP:
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_lock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
this_dbs_info->enable = 0;
|
|
|
|
sysfs_remove_group(&policy->kobj, &dbs_attr_group);
|
|
|
|
dbs_enable--;
|
|
|
|
/*
|
|
|
|
* Stop the timerschedule work, when this governor
|
|
|
|
* is used for first time
|
|
|
|
*/
|
2007-10-22 01:50:13 -06:00
|
|
|
if (dbs_enable == 0) {
|
2005-05-31 20:03:47 -06:00
|
|
|
dbs_timer_exit();
|
2007-10-22 01:50:13 -06:00
|
|
|
cpufreq_unregister_notifier(
|
|
|
|
&dbs_cpufreq_notifier_block,
|
|
|
|
CPUFREQ_TRANSITION_NOTIFIER);
|
|
|
|
}
|
|
|
|
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_unlock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
case CPUFREQ_GOV_LIMITS:
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_lock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
if (policy->max < this_dbs_info->cur_policy->cur)
|
|
|
|
__cpufreq_driver_target(
|
|
|
|
this_dbs_info->cur_policy,
|
2007-10-22 14:49:09 -06:00
|
|
|
policy->max, CPUFREQ_RELATION_H);
|
2005-05-31 20:03:47 -06:00
|
|
|
else if (policy->min > this_dbs_info->cur_policy->cur)
|
|
|
|
__cpufreq_driver_target(
|
|
|
|
this_dbs_info->cur_policy,
|
2007-10-22 14:49:09 -06:00
|
|
|
policy->min, CPUFREQ_RELATION_L);
|
2006-01-13 16:54:22 -07:00
|
|
|
mutex_unlock(&dbs_mutex);
|
2005-05-31 20:03:47 -06:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2008-09-20 08:50:08 -06:00
|
|
|
#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
|
|
|
|
static
|
|
|
|
#endif
|
2007-10-02 14:28:12 -06:00
|
|
|
struct cpufreq_governor cpufreq_gov_conservative = {
|
|
|
|
.name = "conservative",
|
|
|
|
.governor = cpufreq_governor_dbs,
|
|
|
|
.max_transition_latency = TRANSITION_LATENCY_LIMIT,
|
|
|
|
.owner = THIS_MODULE,
|
2005-05-31 20:03:47 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
static int __init cpufreq_gov_dbs_init(void)
|
|
|
|
{
|
2007-10-02 14:28:12 -06:00
|
|
|
return cpufreq_register_governor(&cpufreq_gov_conservative);
|
2005-05-31 20:03:47 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit cpufreq_gov_dbs_exit(void)
|
|
|
|
{
|
|
|
|
/* Make sure that the scheduled work is indeed not running */
|
|
|
|
flush_scheduled_work();
|
|
|
|
|
2007-10-02 14:28:12 -06:00
|
|
|
cpufreq_unregister_governor(&cpufreq_gov_conservative);
|
2005-05-31 20:03:47 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
|
2009-02-13 12:01:01 -07:00
|
|
|
MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
|
2009-01-17 23:39:51 -07:00
|
|
|
MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
|
2005-05-31 20:03:47 -06:00
|
|
|
"Low Latency Frequency Transition capable processors "
|
|
|
|
"optimised for use in a battery environment");
|
2009-01-17 23:39:51 -07:00
|
|
|
MODULE_LICENSE("GPL");
|
2005-05-31 20:03:47 -06:00
|
|
|
|
2008-01-17 16:21:08 -07:00
|
|
|
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
|
|
|
|
fs_initcall(cpufreq_gov_dbs_init);
|
|
|
|
#else
|
2005-05-31 20:03:47 -06:00
|
|
|
module_init(cpufreq_gov_dbs_init);
|
2008-01-17 16:21:08 -07:00
|
|
|
#endif
|
2005-05-31 20:03:47 -06:00
|
|
|
module_exit(cpufreq_gov_dbs_exit);
|