Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * drivers/cpufreq/cpufreq_ondemand.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 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/smp.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/interrupt.h> | |
18 | #include <linux/ctype.h> | |
19 | #include <linux/cpufreq.h> | |
20 | #include <linux/sysctl.h> | |
21 | #include <linux/types.h> | |
22 | #include <linux/fs.h> | |
23 | #include <linux/sysfs.h> | |
138a0128 | 24 | #include <linux/cpu.h> |
1da177e4 LT |
25 | #include <linux/sched.h> |
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> | |
3fc54d37 | 31 | #include <linux/mutex.h> |
1da177e4 LT |
32 | |
33 | /* | |
34 | * dbs is used in this file as a shortform for demandbased switching | |
35 | * It helps to keep variable names smaller, simpler | |
36 | */ | |
37 | ||
38 | #define DEF_FREQUENCY_UP_THRESHOLD (80) | |
c29f1403 | 39 | #define MIN_FREQUENCY_UP_THRESHOLD (11) |
1da177e4 LT |
40 | #define MAX_FREQUENCY_UP_THRESHOLD (100) |
41 | ||
32ee8c3e DJ |
42 | /* |
43 | * The polling frequency of this governor depends on the capability of | |
1da177e4 | 44 | * the processor. Default polling frequency is 1000 times the transition |
32ee8c3e DJ |
45 | * latency of the processor. The governor will work on any processor with |
46 | * transition latency <= 10mS, using appropriate sampling | |
1da177e4 LT |
47 | * rate. |
48 | * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) | |
49 | * this governor will not work. | |
50 | * All times here are in uS. | |
51 | */ | |
32ee8c3e | 52 | static unsigned int def_sampling_rate; |
df8b59be DJ |
53 | #define MIN_SAMPLING_RATE_RATIO (2) |
54 | /* for correct statistics, we need at least 10 ticks between each measure */ | |
55 | #define MIN_STAT_SAMPLING_RATE (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10)) | |
56 | #define MIN_SAMPLING_RATE (def_sampling_rate / MIN_SAMPLING_RATE_RATIO) | |
1da177e4 LT |
57 | #define MAX_SAMPLING_RATE (500 * def_sampling_rate) |
58 | #define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) | |
1da177e4 | 59 | #define TRANSITION_LATENCY_LIMIT (10 * 1000) |
1da177e4 LT |
60 | |
61 | static void do_dbs_timer(void *data); | |
62 | ||
63 | struct cpu_dbs_info_s { | |
ccb2fe20 VP |
64 | cputime64_t prev_cpu_idle; |
65 | cputime64_t prev_cpu_wall; | |
32ee8c3e | 66 | struct cpufreq_policy *cur_policy; |
32ee8c3e | 67 | unsigned int enable; |
1da177e4 LT |
68 | }; |
69 | static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); | |
70 | ||
71 | static unsigned int dbs_enable; /* number of CPUs using this policy */ | |
72 | ||
4ec223d0 VP |
73 | /* |
74 | * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug | |
75 | * lock and dbs_mutex. cpu_hotplug lock should always be held before | |
76 | * dbs_mutex. If any function that can potentially take cpu_hotplug lock | |
77 | * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then | |
78 | * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock | |
79 | * is recursive for the same process. -Venki | |
80 | */ | |
32ee8c3e | 81 | static DEFINE_MUTEX (dbs_mutex); |
1da177e4 LT |
82 | static DECLARE_WORK (dbs_work, do_dbs_timer, NULL); |
83 | ||
6810b548 AK |
84 | static struct workqueue_struct *dbs_workq; |
85 | ||
1da177e4 | 86 | struct dbs_tuners { |
32ee8c3e | 87 | unsigned int sampling_rate; |
32ee8c3e DJ |
88 | unsigned int up_threshold; |
89 | unsigned int ignore_nice; | |
1da177e4 LT |
90 | }; |
91 | ||
92 | static struct dbs_tuners dbs_tuners_ins = { | |
32ee8c3e | 93 | .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
9cbad61b | 94 | .ignore_nice = 0, |
1da177e4 LT |
95 | }; |
96 | ||
ccb2fe20 | 97 | static inline cputime64_t get_cpu_idle_time(unsigned int cpu) |
dac1c1a5 | 98 | { |
ccb2fe20 VP |
99 | cputime64_t retval; |
100 | ||
101 | retval = cputime64_add(kstat_cpu(cpu).cpustat.idle, | |
102 | kstat_cpu(cpu).cpustat.iowait); | |
103 | ||
104 | if (dbs_tuners_ins.ignore_nice) | |
105 | retval = cputime64_add(retval, kstat_cpu(cpu).cpustat.nice); | |
106 | ||
107 | return retval; | |
dac1c1a5 DJ |
108 | } |
109 | ||
1da177e4 LT |
110 | /************************** sysfs interface ************************/ |
111 | static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) | |
112 | { | |
113 | return sprintf (buf, "%u\n", MAX_SAMPLING_RATE); | |
114 | } | |
115 | ||
116 | static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) | |
117 | { | |
118 | return sprintf (buf, "%u\n", MIN_SAMPLING_RATE); | |
119 | } | |
120 | ||
32ee8c3e DJ |
121 | #define define_one_ro(_name) \ |
122 | static struct freq_attr _name = \ | |
1da177e4 LT |
123 | __ATTR(_name, 0444, show_##_name, NULL) |
124 | ||
125 | define_one_ro(sampling_rate_max); | |
126 | define_one_ro(sampling_rate_min); | |
127 | ||
128 | /* cpufreq_ondemand Governor Tunables */ | |
129 | #define show_one(file_name, object) \ | |
130 | static ssize_t show_##file_name \ | |
131 | (struct cpufreq_policy *unused, char *buf) \ | |
132 | { \ | |
133 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ | |
134 | } | |
135 | show_one(sampling_rate, sampling_rate); | |
1da177e4 | 136 | show_one(up_threshold, up_threshold); |
001893cd | 137 | show_one(ignore_nice_load, ignore_nice); |
1da177e4 | 138 | |
32ee8c3e | 139 | static ssize_t store_sampling_rate(struct cpufreq_policy *unused, |
1da177e4 LT |
140 | const char *buf, size_t count) |
141 | { | |
142 | unsigned int input; | |
143 | int ret; | |
144 | ret = sscanf (buf, "%u", &input); | |
145 | ||
3fc54d37 | 146 | mutex_lock(&dbs_mutex); |
1da177e4 | 147 | if (ret != 1 || input > MAX_SAMPLING_RATE || input < MIN_SAMPLING_RATE) { |
3fc54d37 | 148 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
149 | return -EINVAL; |
150 | } | |
151 | ||
152 | dbs_tuners_ins.sampling_rate = input; | |
3fc54d37 | 153 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
154 | |
155 | return count; | |
156 | } | |
157 | ||
32ee8c3e | 158 | static ssize_t store_up_threshold(struct cpufreq_policy *unused, |
1da177e4 LT |
159 | const char *buf, size_t count) |
160 | { | |
161 | unsigned int input; | |
162 | int ret; | |
163 | ret = sscanf (buf, "%u", &input); | |
164 | ||
3fc54d37 | 165 | mutex_lock(&dbs_mutex); |
32ee8c3e | 166 | if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || |
c29f1403 | 167 | input < MIN_FREQUENCY_UP_THRESHOLD) { |
3fc54d37 | 168 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
169 | return -EINVAL; |
170 | } | |
171 | ||
172 | dbs_tuners_ins.up_threshold = input; | |
3fc54d37 | 173 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
174 | |
175 | return count; | |
176 | } | |
177 | ||
001893cd | 178 | static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy, |
3d5ee9e5 DJ |
179 | const char *buf, size_t count) |
180 | { | |
181 | unsigned int input; | |
182 | int ret; | |
183 | ||
184 | unsigned int j; | |
32ee8c3e | 185 | |
3d5ee9e5 DJ |
186 | ret = sscanf (buf, "%u", &input); |
187 | if ( ret != 1 ) | |
188 | return -EINVAL; | |
189 | ||
190 | if ( input > 1 ) | |
191 | input = 1; | |
32ee8c3e | 192 | |
3fc54d37 | 193 | mutex_lock(&dbs_mutex); |
3d5ee9e5 | 194 | if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */ |
3fc54d37 | 195 | mutex_unlock(&dbs_mutex); |
3d5ee9e5 DJ |
196 | return count; |
197 | } | |
198 | dbs_tuners_ins.ignore_nice = input; | |
199 | ||
ccb2fe20 | 200 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 201 | for_each_online_cpu(j) { |
ccb2fe20 VP |
202 | struct cpu_dbs_info_s *dbs_info; |
203 | dbs_info = &per_cpu(cpu_dbs_info, j); | |
204 | dbs_info->prev_cpu_idle = get_cpu_idle_time(j); | |
205 | dbs_info->prev_cpu_wall = get_jiffies_64(); | |
3d5ee9e5 | 206 | } |
3fc54d37 | 207 | mutex_unlock(&dbs_mutex); |
3d5ee9e5 DJ |
208 | |
209 | return count; | |
210 | } | |
211 | ||
1da177e4 LT |
212 | #define define_one_rw(_name) \ |
213 | static struct freq_attr _name = \ | |
214 | __ATTR(_name, 0644, show_##_name, store_##_name) | |
215 | ||
216 | define_one_rw(sampling_rate); | |
1da177e4 | 217 | define_one_rw(up_threshold); |
001893cd | 218 | define_one_rw(ignore_nice_load); |
1da177e4 LT |
219 | |
220 | static struct attribute * dbs_attributes[] = { | |
221 | &sampling_rate_max.attr, | |
222 | &sampling_rate_min.attr, | |
223 | &sampling_rate.attr, | |
1da177e4 | 224 | &up_threshold.attr, |
001893cd | 225 | &ignore_nice_load.attr, |
1da177e4 LT |
226 | NULL |
227 | }; | |
228 | ||
229 | static struct attribute_group dbs_attr_group = { | |
230 | .attrs = dbs_attributes, | |
231 | .name = "ondemand", | |
232 | }; | |
233 | ||
234 | /************************** sysfs end ************************/ | |
235 | ||
236 | static void dbs_check_cpu(int cpu) | |
237 | { | |
ccb2fe20 VP |
238 | unsigned int idle_ticks, total_ticks; |
239 | unsigned int load; | |
1da177e4 | 240 | struct cpu_dbs_info_s *this_dbs_info; |
ccb2fe20 | 241 | cputime64_t cur_jiffies; |
1da177e4 LT |
242 | |
243 | struct cpufreq_policy *policy; | |
244 | unsigned int j; | |
245 | ||
246 | this_dbs_info = &per_cpu(cpu_dbs_info, cpu); | |
247 | if (!this_dbs_info->enable) | |
248 | return; | |
249 | ||
250 | policy = this_dbs_info->cur_policy; | |
ccb2fe20 VP |
251 | cur_jiffies = jiffies64_to_cputime64(get_jiffies_64()); |
252 | total_ticks = (unsigned int) cputime64_sub(cur_jiffies, | |
253 | this_dbs_info->prev_cpu_wall); | |
254 | this_dbs_info->prev_cpu_wall = cur_jiffies; | |
32ee8c3e | 255 | /* |
c29f1403 DJ |
256 | * Every sampling_rate, we check, if current idle time is less |
257 | * than 20% (default), then we try to increase frequency | |
ccb2fe20 | 258 | * Every sampling_rate, we look for a the lowest |
c29f1403 DJ |
259 | * frequency which can sustain the load while keeping idle time over |
260 | * 30%. If such a frequency exist, we try to decrease to this frequency. | |
1da177e4 | 261 | * |
32ee8c3e DJ |
262 | * Any frequency increase takes it to the maximum frequency. |
263 | * Frequency reduction happens at minimum steps of | |
264 | * 5% (default) of current frequency | |
1da177e4 LT |
265 | */ |
266 | ||
ccb2fe20 | 267 | /* Get Idle Time */ |
9c7d269b | 268 | idle_ticks = UINT_MAX; |
1da177e4 | 269 | for_each_cpu_mask(j, policy->cpus) { |
ccb2fe20 VP |
270 | cputime64_t total_idle_ticks; |
271 | unsigned int tmp_idle_ticks; | |
1da177e4 LT |
272 | struct cpu_dbs_info_s *j_dbs_info; |
273 | ||
1da177e4 | 274 | j_dbs_info = &per_cpu(cpu_dbs_info, j); |
dac1c1a5 | 275 | total_idle_ticks = get_cpu_idle_time(j); |
ccb2fe20 VP |
276 | tmp_idle_ticks = (unsigned int) cputime64_sub(total_idle_ticks, |
277 | j_dbs_info->prev_cpu_idle); | |
278 | j_dbs_info->prev_cpu_idle = total_idle_ticks; | |
1da177e4 LT |
279 | |
280 | if (tmp_idle_ticks < idle_ticks) | |
281 | idle_ticks = tmp_idle_ticks; | |
282 | } | |
ccb2fe20 | 283 | load = (100 * (total_ticks - idle_ticks)) / total_ticks; |
1da177e4 | 284 | |
ccb2fe20 VP |
285 | /* Check for frequency increase */ |
286 | if (load > dbs_tuners_ins.up_threshold) { | |
c11420a6 DJ |
287 | /* if we are already at full speed then break out early */ |
288 | if (policy->cur == policy->max) | |
289 | return; | |
32ee8c3e DJ |
290 | |
291 | __cpufreq_driver_target(policy, policy->max, | |
1da177e4 | 292 | CPUFREQ_RELATION_H); |
1da177e4 LT |
293 | return; |
294 | } | |
295 | ||
296 | /* Check for frequency decrease */ | |
c29f1403 DJ |
297 | /* if we cannot reduce the frequency anymore, break out early */ |
298 | if (policy->cur == policy->min) | |
299 | return; | |
1da177e4 | 300 | |
c29f1403 DJ |
301 | /* |
302 | * The optimal frequency is the frequency that is the lowest that | |
303 | * can support the current CPU usage without triggering the up | |
304 | * policy. To be safe, we focus 10 points under the threshold. | |
305 | */ | |
ccb2fe20 VP |
306 | if (load < (dbs_tuners_ins.up_threshold - 10)) { |
307 | unsigned int freq_next; | |
308 | freq_next = (policy->cur * load) / | |
c29f1403 | 309 | (dbs_tuners_ins.up_threshold - 10); |
1da177e4 | 310 | |
c29f1403 | 311 | __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_L); |
ccb2fe20 | 312 | } |
1da177e4 LT |
313 | } |
314 | ||
315 | static void do_dbs_timer(void *data) | |
32ee8c3e | 316 | { |
1da177e4 | 317 | int i; |
4ec223d0 | 318 | lock_cpu_hotplug(); |
3fc54d37 | 319 | mutex_lock(&dbs_mutex); |
6fe71165 DJ |
320 | for_each_online_cpu(i) |
321 | dbs_check_cpu(i); | |
6810b548 AK |
322 | queue_delayed_work(dbs_workq, &dbs_work, |
323 | usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); | |
3fc54d37 | 324 | mutex_unlock(&dbs_mutex); |
4ec223d0 | 325 | unlock_cpu_hotplug(); |
32ee8c3e | 326 | } |
1da177e4 LT |
327 | |
328 | static inline void dbs_timer_init(void) | |
329 | { | |
330 | INIT_WORK(&dbs_work, do_dbs_timer, NULL); | |
6810b548 AK |
331 | if (!dbs_workq) |
332 | dbs_workq = create_singlethread_workqueue("ondemand"); | |
333 | if (!dbs_workq) { | |
334 | printk(KERN_ERR "ondemand: Cannot initialize kernel thread\n"); | |
335 | return; | |
336 | } | |
337 | queue_delayed_work(dbs_workq, &dbs_work, | |
338 | usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); | |
1da177e4 LT |
339 | return; |
340 | } | |
341 | ||
342 | static inline void dbs_timer_exit(void) | |
343 | { | |
6810b548 AK |
344 | if (dbs_workq) |
345 | cancel_rearming_delayed_workqueue(dbs_workq, &dbs_work); | |
1da177e4 LT |
346 | } |
347 | ||
348 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, | |
349 | unsigned int event) | |
350 | { | |
351 | unsigned int cpu = policy->cpu; | |
352 | struct cpu_dbs_info_s *this_dbs_info; | |
353 | unsigned int j; | |
354 | ||
355 | this_dbs_info = &per_cpu(cpu_dbs_info, cpu); | |
356 | ||
357 | switch (event) { | |
358 | case CPUFREQ_GOV_START: | |
32ee8c3e | 359 | if ((!cpu_online(cpu)) || |
1da177e4 LT |
360 | (!policy->cur)) |
361 | return -EINVAL; | |
362 | ||
363 | if (policy->cpuinfo.transition_latency > | |
ff8c288d EP |
364 | (TRANSITION_LATENCY_LIMIT * 1000)) { |
365 | printk(KERN_WARNING "ondemand governor failed to load " | |
366 | "due to too long transition latency\n"); | |
1da177e4 | 367 | return -EINVAL; |
ff8c288d | 368 | } |
1da177e4 LT |
369 | if (this_dbs_info->enable) /* Already enabled */ |
370 | break; | |
32ee8c3e | 371 | |
3fc54d37 | 372 | mutex_lock(&dbs_mutex); |
1da177e4 LT |
373 | for_each_cpu_mask(j, policy->cpus) { |
374 | struct cpu_dbs_info_s *j_dbs_info; | |
375 | j_dbs_info = &per_cpu(cpu_dbs_info, j); | |
376 | j_dbs_info->cur_policy = policy; | |
32ee8c3e | 377 | |
ccb2fe20 VP |
378 | j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j); |
379 | j_dbs_info->prev_cpu_wall = get_jiffies_64(); | |
1da177e4 LT |
380 | } |
381 | this_dbs_info->enable = 1; | |
382 | sysfs_create_group(&policy->kobj, &dbs_attr_group); | |
383 | dbs_enable++; | |
384 | /* | |
385 | * Start the timerschedule work, when this governor | |
386 | * is used for first time | |
387 | */ | |
388 | if (dbs_enable == 1) { | |
389 | unsigned int latency; | |
390 | /* policy latency is in nS. Convert it to uS first */ | |
df8b59be DJ |
391 | latency = policy->cpuinfo.transition_latency / 1000; |
392 | if (latency == 0) | |
393 | latency = 1; | |
1da177e4 | 394 | |
df8b59be | 395 | def_sampling_rate = latency * |
1da177e4 | 396 | DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; |
df8b59be DJ |
397 | |
398 | if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) | |
399 | def_sampling_rate = MIN_STAT_SAMPLING_RATE; | |
400 | ||
1da177e4 | 401 | dbs_tuners_ins.sampling_rate = def_sampling_rate; |
1da177e4 LT |
402 | dbs_timer_init(); |
403 | } | |
32ee8c3e | 404 | |
3fc54d37 | 405 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
406 | break; |
407 | ||
408 | case CPUFREQ_GOV_STOP: | |
3fc54d37 | 409 | mutex_lock(&dbs_mutex); |
1da177e4 LT |
410 | this_dbs_info->enable = 0; |
411 | sysfs_remove_group(&policy->kobj, &dbs_attr_group); | |
412 | dbs_enable--; | |
413 | /* | |
414 | * Stop the timerschedule work, when this governor | |
415 | * is used for first time | |
416 | */ | |
32ee8c3e | 417 | if (dbs_enable == 0) |
1da177e4 | 418 | dbs_timer_exit(); |
32ee8c3e | 419 | |
3fc54d37 | 420 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
421 | |
422 | break; | |
423 | ||
424 | case CPUFREQ_GOV_LIMITS: | |
4ec223d0 | 425 | lock_cpu_hotplug(); |
3fc54d37 | 426 | mutex_lock(&dbs_mutex); |
1da177e4 LT |
427 | if (policy->max < this_dbs_info->cur_policy->cur) |
428 | __cpufreq_driver_target( | |
429 | this_dbs_info->cur_policy, | |
32ee8c3e | 430 | policy->max, CPUFREQ_RELATION_H); |
1da177e4 LT |
431 | else if (policy->min > this_dbs_info->cur_policy->cur) |
432 | __cpufreq_driver_target( | |
433 | this_dbs_info->cur_policy, | |
32ee8c3e | 434 | policy->min, CPUFREQ_RELATION_L); |
3fc54d37 | 435 | mutex_unlock(&dbs_mutex); |
4ec223d0 | 436 | unlock_cpu_hotplug(); |
1da177e4 LT |
437 | break; |
438 | } | |
439 | return 0; | |
440 | } | |
441 | ||
7f335d4e | 442 | static struct cpufreq_governor cpufreq_gov_dbs = { |
1da177e4 LT |
443 | .name = "ondemand", |
444 | .governor = cpufreq_governor_dbs, | |
445 | .owner = THIS_MODULE, | |
446 | }; | |
1da177e4 LT |
447 | |
448 | static int __init cpufreq_gov_dbs_init(void) | |
449 | { | |
450 | return cpufreq_register_governor(&cpufreq_gov_dbs); | |
451 | } | |
452 | ||
453 | static void __exit cpufreq_gov_dbs_exit(void) | |
454 | { | |
6810b548 AK |
455 | /* Make sure that the scheduled work is indeed not running. |
456 | Assumes the timer has been cancelled first. */ | |
457 | if (dbs_workq) { | |
458 | flush_workqueue(dbs_workq); | |
459 | destroy_workqueue(dbs_workq); | |
460 | } | |
1da177e4 LT |
461 | |
462 | cpufreq_unregister_governor(&cpufreq_gov_dbs); | |
463 | } | |
464 | ||
465 | ||
466 | MODULE_AUTHOR ("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); | |
467 | MODULE_DESCRIPTION ("'cpufreq_ondemand' - A dynamic cpufreq governor for " | |
468 | "Low Latency Frequency Transition capable processors"); | |
469 | MODULE_LICENSE ("GPL"); | |
470 | ||
471 | module_init(cpufreq_gov_dbs_init); | |
472 | module_exit(cpufreq_gov_dbs_exit); |