Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 1 | /* |
| 2 | * drivers/cpufreq/cpufreq_conservative.c |
| 3 | * |
| 4 | * Copyright (C) 2001 Russell King |
| 5 | * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>. |
| 6 | * Jun Nakajima <jun.nakajima@intel.com> |
| 7 | * (C) 2004 Alexander Clouter <alex-kernel@digriz.org.uk> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/smp.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <linux/ctype.h> |
| 20 | #include <linux/cpufreq.h> |
| 21 | #include <linux/sysctl.h> |
| 22 | #include <linux/types.h> |
| 23 | #include <linux/fs.h> |
| 24 | #include <linux/sysfs.h> |
Andrew Morton | 138a0128 | 2006-06-23 03:31:19 -0700 | [diff] [blame] | 25 | #include <linux/cpu.h> |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 26 | #include <linux/kmod.h> |
| 27 | #include <linux/workqueue.h> |
| 28 | #include <linux/jiffies.h> |
| 29 | #include <linux/kernel_stat.h> |
| 30 | #include <linux/percpu.h> |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 31 | #include <linux/mutex.h> |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 32 | /* |
| 33 | * dbs is used in this file as a shortform for demandbased switching |
| 34 | * It helps to keep variable names smaller, simpler |
| 35 | */ |
| 36 | |
| 37 | #define DEF_FREQUENCY_UP_THRESHOLD (80) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 38 | #define DEF_FREQUENCY_DOWN_THRESHOLD (20) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 39 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 40 | /* |
| 41 | * The polling frequency of this governor depends on the capability of |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 42 | * the processor. Default polling frequency is 1000 times the transition |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 43 | * latency of the processor. The governor will work on any processor with |
| 44 | * transition latency <= 10mS, using appropriate sampling |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 45 | * rate. |
Gautham R Shenoy | e08f5f5 | 2006-10-26 16:20:58 +0530 | [diff] [blame] | 46 | * For CPUs with transition latency > 10mS (mostly drivers |
| 47 | * with CPUFREQ_ETERNAL), this governor will not work. |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 48 | * All times here are in uS. |
| 49 | */ |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 50 | static unsigned int def_sampling_rate; |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 51 | #define MIN_SAMPLING_RATE_RATIO (2) |
| 52 | /* for correct statistics, we need at least 10 ticks between each measure */ |
Gautham R Shenoy | e08f5f5 | 2006-10-26 16:20:58 +0530 | [diff] [blame] | 53 | #define MIN_STAT_SAMPLING_RATE \ |
| 54 | (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10)) |
| 55 | #define MIN_SAMPLING_RATE \ |
| 56 | (def_sampling_rate / MIN_SAMPLING_RATE_RATIO) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 57 | #define MAX_SAMPLING_RATE (500 * def_sampling_rate) |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 58 | #define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) |
| 59 | #define DEF_SAMPLING_DOWN_FACTOR (1) |
| 60 | #define MAX_SAMPLING_DOWN_FACTOR (10) |
Thomas Renninger | 1c25624 | 2007-10-02 13:28:12 -0700 | [diff] [blame] | 61 | #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 62 | |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 63 | static void do_dbs_timer(struct work_struct *work); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 64 | |
| 65 | struct cpu_dbs_info_s { |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 66 | struct cpufreq_policy *cur_policy; |
| 67 | unsigned int prev_cpu_idle_up; |
| 68 | unsigned int prev_cpu_idle_down; |
| 69 | unsigned int enable; |
| 70 | unsigned int down_skip; |
| 71 | unsigned int requested_freq; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 72 | }; |
| 73 | static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); |
| 74 | |
| 75 | static unsigned int dbs_enable; /* number of CPUs using this policy */ |
| 76 | |
Venkatesh Pallipadi | 4ec223d | 2006-06-21 15:18:34 -0700 | [diff] [blame] | 77 | /* |
| 78 | * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug |
| 79 | * lock and dbs_mutex. cpu_hotplug lock should always be held before |
| 80 | * dbs_mutex. If any function that can potentially take cpu_hotplug lock |
| 81 | * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then |
| 82 | * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock |
| 83 | * is recursive for the same process. -Venki |
| 84 | */ |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 85 | static DEFINE_MUTEX (dbs_mutex); |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 86 | static DECLARE_DELAYED_WORK(dbs_work, do_dbs_timer); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 87 | |
| 88 | struct dbs_tuners { |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 89 | unsigned int sampling_rate; |
| 90 | unsigned int sampling_down_factor; |
| 91 | unsigned int up_threshold; |
| 92 | unsigned int down_threshold; |
| 93 | unsigned int ignore_nice; |
| 94 | unsigned int freq_step; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 95 | }; |
| 96 | |
| 97 | static struct dbs_tuners dbs_tuners_ins = { |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 98 | .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
| 99 | .down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD, |
| 100 | .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, |
| 101 | .ignore_nice = 0, |
| 102 | .freq_step = 5, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 103 | }; |
| 104 | |
Dave Jones | dac1c1a | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 105 | static inline unsigned int get_cpu_idle_time(unsigned int cpu) |
| 106 | { |
Gautham R Shenoy | e08f5f5 | 2006-10-26 16:20:58 +0530 | [diff] [blame] | 107 | unsigned int add_nice = 0, ret; |
| 108 | |
| 109 | if (dbs_tuners_ins.ignore_nice) |
| 110 | add_nice = kstat_cpu(cpu).cpustat.nice; |
| 111 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 112 | ret = kstat_cpu(cpu).cpustat.idle + |
Dave Jones | dac1c1a | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 113 | kstat_cpu(cpu).cpustat.iowait + |
Gautham R Shenoy | e08f5f5 | 2006-10-26 16:20:58 +0530 | [diff] [blame] | 114 | add_nice; |
| 115 | |
| 116 | return ret; |
Dave Jones | dac1c1a | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 117 | } |
| 118 | |
Elias Oltmanns | a8d7c3b | 2007-10-22 09:50:13 +0200 | [diff] [blame] | 119 | /* keep track of frequency transitions */ |
| 120 | static int |
| 121 | dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, |
| 122 | void *data) |
| 123 | { |
| 124 | struct cpufreq_freqs *freq = data; |
| 125 | struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, |
| 126 | freq->cpu); |
| 127 | |
| 128 | if (!this_dbs_info->enable) |
| 129 | return 0; |
| 130 | |
| 131 | this_dbs_info->requested_freq = freq->new; |
| 132 | |
| 133 | return 0; |
| 134 | } |
| 135 | |
| 136 | static struct notifier_block dbs_cpufreq_notifier_block = { |
| 137 | .notifier_call = dbs_cpufreq_notifier |
| 138 | }; |
| 139 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 140 | /************************** sysfs interface ************************/ |
| 141 | static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) |
| 142 | { |
| 143 | return sprintf (buf, "%u\n", MAX_SAMPLING_RATE); |
| 144 | } |
| 145 | |
| 146 | static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) |
| 147 | { |
| 148 | return sprintf (buf, "%u\n", MIN_SAMPLING_RATE); |
| 149 | } |
| 150 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 151 | #define define_one_ro(_name) \ |
| 152 | static struct freq_attr _name = \ |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 153 | __ATTR(_name, 0444, show_##_name, NULL) |
| 154 | |
| 155 | define_one_ro(sampling_rate_max); |
| 156 | define_one_ro(sampling_rate_min); |
| 157 | |
| 158 | /* cpufreq_conservative Governor Tunables */ |
| 159 | #define show_one(file_name, object) \ |
| 160 | static ssize_t show_##file_name \ |
| 161 | (struct cpufreq_policy *unused, char *buf) \ |
| 162 | { \ |
| 163 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ |
| 164 | } |
| 165 | show_one(sampling_rate, sampling_rate); |
| 166 | show_one(sampling_down_factor, sampling_down_factor); |
| 167 | show_one(up_threshold, up_threshold); |
| 168 | show_one(down_threshold, down_threshold); |
Alexander Clouter | 001893c | 2005-12-01 01:09:25 -0800 | [diff] [blame] | 169 | show_one(ignore_nice_load, ignore_nice); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 170 | show_one(freq_step, freq_step); |
| 171 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 172 | static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 173 | const char *buf, size_t count) |
| 174 | { |
| 175 | unsigned int input; |
| 176 | int ret; |
| 177 | ret = sscanf (buf, "%u", &input); |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 178 | if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 179 | return -EINVAL; |
| 180 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 181 | mutex_lock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 182 | dbs_tuners_ins.sampling_down_factor = input; |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 183 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 184 | |
| 185 | return count; |
| 186 | } |
| 187 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 188 | static ssize_t store_sampling_rate(struct cpufreq_policy *unused, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 189 | const char *buf, size_t count) |
| 190 | { |
| 191 | unsigned int input; |
| 192 | int ret; |
| 193 | ret = sscanf (buf, "%u", &input); |
| 194 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 195 | mutex_lock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 196 | if (ret != 1 || input > MAX_SAMPLING_RATE || input < MIN_SAMPLING_RATE) { |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 197 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 198 | return -EINVAL; |
| 199 | } |
| 200 | |
| 201 | dbs_tuners_ins.sampling_rate = input; |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 202 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 203 | |
| 204 | return count; |
| 205 | } |
| 206 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 207 | static ssize_t store_up_threshold(struct cpufreq_policy *unused, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 208 | const char *buf, size_t count) |
| 209 | { |
| 210 | unsigned int input; |
| 211 | int ret; |
| 212 | ret = sscanf (buf, "%u", &input); |
| 213 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 214 | mutex_lock(&dbs_mutex); |
Dave Jones | b82fbe6 | 2006-04-01 22:07:07 -0500 | [diff] [blame] | 215 | if (ret != 1 || input > 100 || input <= dbs_tuners_ins.down_threshold) { |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 216 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 217 | return -EINVAL; |
| 218 | } |
| 219 | |
| 220 | dbs_tuners_ins.up_threshold = input; |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 221 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 222 | |
| 223 | return count; |
| 224 | } |
| 225 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 226 | static ssize_t store_down_threshold(struct cpufreq_policy *unused, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 227 | const char *buf, size_t count) |
| 228 | { |
| 229 | unsigned int input; |
| 230 | int ret; |
| 231 | ret = sscanf (buf, "%u", &input); |
| 232 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 233 | mutex_lock(&dbs_mutex); |
Dave Jones | b82fbe6 | 2006-04-01 22:07:07 -0500 | [diff] [blame] | 234 | if (ret != 1 || input > 100 || input >= dbs_tuners_ins.up_threshold) { |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 235 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 236 | return -EINVAL; |
| 237 | } |
| 238 | |
| 239 | dbs_tuners_ins.down_threshold = input; |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 240 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 241 | |
| 242 | return count; |
| 243 | } |
| 244 | |
Alexander Clouter | 001893c | 2005-12-01 01:09:25 -0800 | [diff] [blame] | 245 | static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 246 | const char *buf, size_t count) |
| 247 | { |
| 248 | unsigned int input; |
| 249 | int ret; |
| 250 | |
| 251 | unsigned int j; |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 252 | |
| 253 | ret = sscanf(buf, "%u", &input); |
| 254 | if (ret != 1) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 255 | return -EINVAL; |
| 256 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 257 | if (input > 1) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 258 | input = 1; |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 259 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 260 | mutex_lock(&dbs_mutex); |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 261 | if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 262 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 263 | return count; |
| 264 | } |
| 265 | dbs_tuners_ins.ignore_nice = input; |
| 266 | |
| 267 | /* we need to re-evaluate prev_cpu_idle_up and prev_cpu_idle_down */ |
Dave Jones | dac1c1a | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 268 | for_each_online_cpu(j) { |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 269 | struct cpu_dbs_info_s *j_dbs_info; |
| 270 | j_dbs_info = &per_cpu(cpu_dbs_info, j); |
Dave Jones | dac1c1a | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 271 | j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 272 | j_dbs_info->prev_cpu_idle_down = j_dbs_info->prev_cpu_idle_up; |
| 273 | } |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 274 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 275 | |
| 276 | return count; |
| 277 | } |
| 278 | |
| 279 | static ssize_t store_freq_step(struct cpufreq_policy *policy, |
| 280 | const char *buf, size_t count) |
| 281 | { |
| 282 | unsigned int input; |
| 283 | int ret; |
| 284 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 285 | ret = sscanf(buf, "%u", &input); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 286 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 287 | if (ret != 1) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 288 | return -EINVAL; |
| 289 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 290 | if (input > 100) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 291 | input = 100; |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 292 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 293 | /* no need to test here if freq_step is zero as the user might actually |
| 294 | * want this, they would be crazy though :) */ |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 295 | mutex_lock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 296 | dbs_tuners_ins.freq_step = input; |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 297 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 298 | |
| 299 | return count; |
| 300 | } |
| 301 | |
| 302 | #define define_one_rw(_name) \ |
| 303 | static struct freq_attr _name = \ |
| 304 | __ATTR(_name, 0644, show_##_name, store_##_name) |
| 305 | |
| 306 | define_one_rw(sampling_rate); |
| 307 | define_one_rw(sampling_down_factor); |
| 308 | define_one_rw(up_threshold); |
| 309 | define_one_rw(down_threshold); |
Alexander Clouter | 001893c | 2005-12-01 01:09:25 -0800 | [diff] [blame] | 310 | define_one_rw(ignore_nice_load); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 311 | define_one_rw(freq_step); |
| 312 | |
| 313 | static struct attribute * dbs_attributes[] = { |
| 314 | &sampling_rate_max.attr, |
| 315 | &sampling_rate_min.attr, |
| 316 | &sampling_rate.attr, |
| 317 | &sampling_down_factor.attr, |
| 318 | &up_threshold.attr, |
| 319 | &down_threshold.attr, |
Alexander Clouter | 001893c | 2005-12-01 01:09:25 -0800 | [diff] [blame] | 320 | &ignore_nice_load.attr, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 321 | &freq_step.attr, |
| 322 | NULL |
| 323 | }; |
| 324 | |
| 325 | static struct attribute_group dbs_attr_group = { |
| 326 | .attrs = dbs_attributes, |
| 327 | .name = "conservative", |
| 328 | }; |
| 329 | |
| 330 | /************************** sysfs end ************************/ |
| 331 | |
| 332 | static void dbs_check_cpu(int cpu) |
| 333 | { |
| 334 | unsigned int idle_ticks, up_idle_ticks, down_idle_ticks; |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 335 | unsigned int tmp_idle_ticks, total_idle_ticks; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 336 | unsigned int freq_step; |
| 337 | unsigned int freq_down_sampling_rate; |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 338 | struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 339 | struct cpufreq_policy *policy; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 340 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 341 | if (!this_dbs_info->enable) |
| 342 | return; |
| 343 | |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 344 | policy = this_dbs_info->cur_policy; |
| 345 | |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 346 | /* |
| 347 | * The default safe range is 20% to 80% |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 348 | * Every sampling_rate, we check |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 349 | * - If current idle time is less than 20%, then we try to |
| 350 | * increase frequency |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 351 | * Every sampling_rate*sampling_down_factor, we check |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 352 | * - If current idle time is more than 80%, then we try to |
| 353 | * decrease frequency |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 354 | * |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 355 | * Any frequency increase takes it to the maximum frequency. |
| 356 | * Frequency reduction happens at minimum steps of |
| 357 | * 5% (default) of max_frequency |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 358 | */ |
| 359 | |
| 360 | /* Check for frequency increase */ |
Dave Jones | 9c7d269 | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 361 | idle_ticks = UINT_MAX; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 362 | |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 363 | /* Check for frequency increase */ |
| 364 | total_idle_ticks = get_cpu_idle_time(cpu); |
| 365 | tmp_idle_ticks = total_idle_ticks - |
| 366 | this_dbs_info->prev_cpu_idle_up; |
| 367 | this_dbs_info->prev_cpu_idle_up = total_idle_ticks; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 368 | |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 369 | if (tmp_idle_ticks < idle_ticks) |
| 370 | idle_ticks = tmp_idle_ticks; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 371 | |
| 372 | /* Scale idle ticks by 100 and compare with up and down ticks */ |
| 373 | idle_ticks *= 100; |
| 374 | up_idle_ticks = (100 - dbs_tuners_ins.up_threshold) * |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 375 | usecs_to_jiffies(dbs_tuners_ins.sampling_rate); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 376 | |
| 377 | if (idle_ticks < up_idle_ticks) { |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 378 | this_dbs_info->down_skip = 0; |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 379 | this_dbs_info->prev_cpu_idle_down = |
| 380 | this_dbs_info->prev_cpu_idle_up; |
Dave Jones | 790d76f | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 381 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 382 | /* if we are already at full speed then break out early */ |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 383 | if (this_dbs_info->requested_freq == policy->max) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 384 | return; |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 385 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 386 | freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100; |
| 387 | |
| 388 | /* max freq cannot be less than 100. But who knows.... */ |
| 389 | if (unlikely(freq_step == 0)) |
| 390 | freq_step = 5; |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 391 | |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 392 | this_dbs_info->requested_freq += freq_step; |
| 393 | if (this_dbs_info->requested_freq > policy->max) |
| 394 | this_dbs_info->requested_freq = policy->max; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 395 | |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 396 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 397 | CPUFREQ_RELATION_H); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 398 | return; |
| 399 | } |
| 400 | |
| 401 | /* Check for frequency decrease */ |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 402 | this_dbs_info->down_skip++; |
| 403 | if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 404 | return; |
| 405 | |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 406 | /* Check for frequency decrease */ |
| 407 | total_idle_ticks = this_dbs_info->prev_cpu_idle_up; |
| 408 | tmp_idle_ticks = total_idle_ticks - |
| 409 | this_dbs_info->prev_cpu_idle_down; |
| 410 | this_dbs_info->prev_cpu_idle_down = total_idle_ticks; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 411 | |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 412 | if (tmp_idle_ticks < idle_ticks) |
| 413 | idle_ticks = tmp_idle_ticks; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 414 | |
| 415 | /* Scale idle ticks by 100 and compare with up and down ticks */ |
| 416 | idle_ticks *= 100; |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 417 | this_dbs_info->down_skip = 0; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 418 | |
| 419 | freq_down_sampling_rate = dbs_tuners_ins.sampling_rate * |
| 420 | dbs_tuners_ins.sampling_down_factor; |
| 421 | down_idle_ticks = (100 - dbs_tuners_ins.down_threshold) * |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 422 | usecs_to_jiffies(freq_down_sampling_rate); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 423 | |
Dave Jones | 9c7d269 | 2005-05-31 19:03:49 -0700 | [diff] [blame] | 424 | if (idle_ticks > down_idle_ticks) { |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 425 | /* |
| 426 | * if we are already at the lowest speed then break out early |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 427 | * or if we 'cannot' reduce the speed as the user might want |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 428 | * freq_step to be zero |
| 429 | */ |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 430 | if (this_dbs_info->requested_freq == policy->min |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 431 | || dbs_tuners_ins.freq_step == 0) |
| 432 | return; |
| 433 | |
| 434 | freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100; |
| 435 | |
| 436 | /* max freq cannot be less than 100. But who knows.... */ |
| 437 | if (unlikely(freq_step == 0)) |
| 438 | freq_step = 5; |
| 439 | |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 440 | this_dbs_info->requested_freq -= freq_step; |
| 441 | if (this_dbs_info->requested_freq < policy->min) |
| 442 | this_dbs_info->requested_freq = policy->min; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 443 | |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 444 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 445 | CPUFREQ_RELATION_H); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 446 | return; |
| 447 | } |
| 448 | } |
| 449 | |
David Howells | c402895 | 2006-11-22 14:57:56 +0000 | [diff] [blame] | 450 | static void do_dbs_timer(struct work_struct *work) |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 451 | { |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 452 | int i; |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 453 | mutex_lock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 454 | for_each_online_cpu(i) |
| 455 | dbs_check_cpu(i); |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 456 | schedule_delayed_work(&dbs_work, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 457 | usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 458 | mutex_unlock(&dbs_mutex); |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 459 | } |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 460 | |
| 461 | static inline void dbs_timer_init(void) |
| 462 | { |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 463 | schedule_delayed_work(&dbs_work, |
| 464 | usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); |
| 465 | return; |
| 466 | } |
| 467 | |
| 468 | static inline void dbs_timer_exit(void) |
| 469 | { |
| 470 | cancel_delayed_work(&dbs_work); |
| 471 | return; |
| 472 | } |
| 473 | |
| 474 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, |
| 475 | unsigned int event) |
| 476 | { |
| 477 | unsigned int cpu = policy->cpu; |
| 478 | struct cpu_dbs_info_s *this_dbs_info; |
| 479 | unsigned int j; |
Jeff Garzik | 914f7c3 | 2006-10-20 14:31:00 -0700 | [diff] [blame] | 480 | int rc; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 481 | |
| 482 | this_dbs_info = &per_cpu(cpu_dbs_info, cpu); |
| 483 | |
| 484 | switch (event) { |
| 485 | case CPUFREQ_GOV_START: |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 486 | if ((!cpu_online(cpu)) || (!policy->cur)) |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 487 | return -EINVAL; |
| 488 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 489 | if (this_dbs_info->enable) /* Already enabled */ |
| 490 | break; |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 491 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 492 | mutex_lock(&dbs_mutex); |
Jeff Garzik | 914f7c3 | 2006-10-20 14:31:00 -0700 | [diff] [blame] | 493 | |
| 494 | rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); |
| 495 | if (rc) { |
| 496 | mutex_unlock(&dbs_mutex); |
| 497 | return rc; |
| 498 | } |
| 499 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 500 | for_each_cpu_mask(j, policy->cpus) { |
| 501 | struct cpu_dbs_info_s *j_dbs_info; |
| 502 | j_dbs_info = &per_cpu(cpu_dbs_info, j); |
| 503 | j_dbs_info->cur_policy = policy; |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 504 | |
Alexander Clouter | 08a28e2 | 2006-03-22 09:59:16 +0000 | [diff] [blame] | 505 | j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(cpu); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 506 | j_dbs_info->prev_cpu_idle_down |
| 507 | = j_dbs_info->prev_cpu_idle_up; |
| 508 | } |
| 509 | this_dbs_info->enable = 1; |
Alexander Clouter | a159b82 | 2006-03-22 10:00:18 +0000 | [diff] [blame] | 510 | this_dbs_info->down_skip = 0; |
| 511 | this_dbs_info->requested_freq = policy->cur; |
Jeff Garzik | 914f7c3 | 2006-10-20 14:31:00 -0700 | [diff] [blame] | 512 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 513 | dbs_enable++; |
| 514 | /* |
| 515 | * Start the timerschedule work, when this governor |
| 516 | * is used for first time |
| 517 | */ |
| 518 | if (dbs_enable == 1) { |
| 519 | unsigned int latency; |
| 520 | /* policy latency is in nS. Convert it to uS first */ |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 521 | latency = policy->cpuinfo.transition_latency / 1000; |
| 522 | if (latency == 0) |
| 523 | latency = 1; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 524 | |
Alexander Clouter | e8a0257 | 2006-03-22 09:56:23 +0000 | [diff] [blame] | 525 | def_sampling_rate = 10 * latency * |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 526 | DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; |
Alexander Clouter | 2c906b3 | 2006-03-22 09:54:10 +0000 | [diff] [blame] | 527 | |
| 528 | if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) |
| 529 | def_sampling_rate = MIN_STAT_SAMPLING_RATE; |
| 530 | |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 531 | dbs_tuners_ins.sampling_rate = def_sampling_rate; |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 532 | |
| 533 | dbs_timer_init(); |
Elias Oltmanns | a8d7c3b | 2007-10-22 09:50:13 +0200 | [diff] [blame] | 534 | cpufreq_register_notifier( |
| 535 | &dbs_cpufreq_notifier_block, |
| 536 | CPUFREQ_TRANSITION_NOTIFIER); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 537 | } |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 538 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 539 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 540 | break; |
| 541 | |
| 542 | case CPUFREQ_GOV_STOP: |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 543 | mutex_lock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 544 | this_dbs_info->enable = 0; |
| 545 | sysfs_remove_group(&policy->kobj, &dbs_attr_group); |
| 546 | dbs_enable--; |
| 547 | /* |
| 548 | * Stop the timerschedule work, when this governor |
| 549 | * is used for first time |
| 550 | */ |
Elias Oltmanns | a8d7c3b | 2007-10-22 09:50:13 +0200 | [diff] [blame] | 551 | if (dbs_enable == 0) { |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 552 | dbs_timer_exit(); |
Elias Oltmanns | a8d7c3b | 2007-10-22 09:50:13 +0200 | [diff] [blame] | 553 | cpufreq_unregister_notifier( |
| 554 | &dbs_cpufreq_notifier_block, |
| 555 | CPUFREQ_TRANSITION_NOTIFIER); |
| 556 | } |
| 557 | |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 558 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 559 | |
| 560 | break; |
| 561 | |
| 562 | case CPUFREQ_GOV_LIMITS: |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 563 | mutex_lock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 564 | if (policy->max < this_dbs_info->cur_policy->cur) |
| 565 | __cpufreq_driver_target( |
| 566 | this_dbs_info->cur_policy, |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 567 | policy->max, CPUFREQ_RELATION_H); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 568 | else if (policy->min > this_dbs_info->cur_policy->cur) |
| 569 | __cpufreq_driver_target( |
| 570 | this_dbs_info->cur_policy, |
Dave Jones | 18a7247 | 2007-10-22 16:49:09 -0400 | [diff] [blame] | 571 | policy->min, CPUFREQ_RELATION_L); |
akpm@osdl.org | 3fc54d3 | 2006-01-13 15:54:22 -0800 | [diff] [blame] | 572 | mutex_unlock(&dbs_mutex); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 573 | break; |
| 574 | } |
| 575 | return 0; |
| 576 | } |
| 577 | |
Thomas Renninger | 1c25624 | 2007-10-02 13:28:12 -0700 | [diff] [blame] | 578 | struct cpufreq_governor cpufreq_gov_conservative = { |
| 579 | .name = "conservative", |
| 580 | .governor = cpufreq_governor_dbs, |
| 581 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, |
| 582 | .owner = THIS_MODULE, |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 583 | }; |
Thomas Renninger | 1c25624 | 2007-10-02 13:28:12 -0700 | [diff] [blame] | 584 | EXPORT_SYMBOL(cpufreq_gov_conservative); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 585 | |
| 586 | static int __init cpufreq_gov_dbs_init(void) |
| 587 | { |
Thomas Renninger | 1c25624 | 2007-10-02 13:28:12 -0700 | [diff] [blame] | 588 | return cpufreq_register_governor(&cpufreq_gov_conservative); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 589 | } |
| 590 | |
| 591 | static void __exit cpufreq_gov_dbs_exit(void) |
| 592 | { |
| 593 | /* Make sure that the scheduled work is indeed not running */ |
| 594 | flush_scheduled_work(); |
| 595 | |
Thomas Renninger | 1c25624 | 2007-10-02 13:28:12 -0700 | [diff] [blame] | 596 | cpufreq_unregister_governor(&cpufreq_gov_conservative); |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 597 | } |
| 598 | |
| 599 | |
| 600 | MODULE_AUTHOR ("Alexander Clouter <alex-kernel@digriz.org.uk>"); |
| 601 | MODULE_DESCRIPTION ("'cpufreq_conservative' - A dynamic cpufreq governor for " |
| 602 | "Low Latency Frequency Transition capable processors " |
| 603 | "optimised for use in a battery environment"); |
| 604 | MODULE_LICENSE ("GPL"); |
| 605 | |
Johannes Weiner | 6915719 | 2008-01-17 15:21:08 -0800 | [diff] [blame] | 606 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
| 607 | fs_initcall(cpufreq_gov_dbs_init); |
| 608 | #else |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 609 | module_init(cpufreq_gov_dbs_init); |
Johannes Weiner | 6915719 | 2008-01-17 15:21:08 -0800 | [diff] [blame] | 610 | #endif |
Dave Jones | b917083 | 2005-05-31 19:03:47 -0700 | [diff] [blame] | 611 | module_exit(cpufreq_gov_dbs_exit); |