Commit | Line | Data |
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b9170836 DJ |
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> | |
11a80a9c | 7 | * (C) 2009 Alexander Clouter <alex@digriz.org.uk> |
b9170836 DJ |
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> | |
b9170836 | 16 | #include <linux/init.h> |
b9170836 | 17 | #include <linux/cpufreq.h> |
138a0128 | 18 | #include <linux/cpu.h> |
b9170836 DJ |
19 | #include <linux/jiffies.h> |
20 | #include <linux/kernel_stat.h> | |
3fc54d37 | 21 | #include <linux/mutex.h> |
8e677ce8 AC |
22 | #include <linux/hrtimer.h> |
23 | #include <linux/tick.h> | |
24 | #include <linux/ktime.h> | |
25 | #include <linux/sched.h> | |
26 | ||
b9170836 DJ |
27 | /* |
28 | * dbs is used in this file as a shortform for demandbased switching | |
29 | * It helps to keep variable names smaller, simpler | |
30 | */ | |
31 | ||
32 | #define DEF_FREQUENCY_UP_THRESHOLD (80) | |
b9170836 | 33 | #define DEF_FREQUENCY_DOWN_THRESHOLD (20) |
b9170836 | 34 | |
18a7247d DJ |
35 | /* |
36 | * The polling frequency of this governor depends on the capability of | |
b9170836 | 37 | * the processor. Default polling frequency is 1000 times the transition |
18a7247d DJ |
38 | * latency of the processor. The governor will work on any processor with |
39 | * transition latency <= 10mS, using appropriate sampling | |
b9170836 | 40 | * rate. |
8e677ce8 AC |
41 | * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) |
42 | * this governor will not work. | |
b9170836 DJ |
43 | * All times here are in uS. |
44 | */ | |
2c906b31 | 45 | #define MIN_SAMPLING_RATE_RATIO (2) |
112124ab | 46 | |
cef9615a TR |
47 | static unsigned int min_sampling_rate; |
48 | ||
112124ab | 49 | #define LATENCY_MULTIPLIER (1000) |
cef9615a | 50 | #define MIN_LATENCY_MULTIPLIER (100) |
2c906b31 AC |
51 | #define DEF_SAMPLING_DOWN_FACTOR (1) |
52 | #define MAX_SAMPLING_DOWN_FACTOR (10) | |
1c256245 | 53 | #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) |
b9170836 | 54 | |
c4028958 | 55 | static void do_dbs_timer(struct work_struct *work); |
b9170836 DJ |
56 | |
57 | struct cpu_dbs_info_s { | |
8e677ce8 AC |
58 | cputime64_t prev_cpu_idle; |
59 | cputime64_t prev_cpu_wall; | |
60 | cputime64_t prev_cpu_nice; | |
18a7247d | 61 | struct cpufreq_policy *cur_policy; |
8e677ce8 | 62 | struct delayed_work work; |
18a7247d DJ |
63 | unsigned int down_skip; |
64 | unsigned int requested_freq; | |
8e677ce8 AC |
65 | int cpu; |
66 | unsigned int enable:1; | |
ee88415c | 67 | /* |
68 | * percpu mutex that serializes governor limit change with | |
69 | * do_dbs_timer invocation. We do not want do_dbs_timer to run | |
70 | * when user is changing the governor or limits. | |
71 | */ | |
72 | struct mutex timer_mutex; | |
b9170836 | 73 | }; |
245b2e70 | 74 | static DEFINE_PER_CPU(struct cpu_dbs_info_s, cs_cpu_dbs_info); |
b9170836 DJ |
75 | |
76 | static unsigned int dbs_enable; /* number of CPUs using this policy */ | |
77 | ||
4ec223d0 | 78 | /* |
7d26e2d5 | 79 | * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on |
ee88415c | 80 | * different CPUs. It protects dbs_enable in governor start/stop. |
4ec223d0 | 81 | */ |
9acef487 | 82 | static DEFINE_MUTEX(dbs_mutex); |
b9170836 | 83 | |
8e677ce8 AC |
84 | static struct workqueue_struct *kconservative_wq; |
85 | ||
86 | static struct dbs_tuners { | |
18a7247d DJ |
87 | unsigned int sampling_rate; |
88 | unsigned int sampling_down_factor; | |
89 | unsigned int up_threshold; | |
90 | unsigned int down_threshold; | |
91 | unsigned int ignore_nice; | |
92 | unsigned int freq_step; | |
8e677ce8 | 93 | } dbs_tuners_ins = { |
18a7247d DJ |
94 | .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
95 | .down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD, | |
96 | .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, | |
97 | .ignore_nice = 0, | |
98 | .freq_step = 5, | |
b9170836 DJ |
99 | }; |
100 | ||
8e677ce8 AC |
101 | static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu, |
102 | cputime64_t *wall) | |
dac1c1a5 | 103 | { |
8e677ce8 AC |
104 | cputime64_t idle_time; |
105 | cputime64_t cur_wall_time; | |
106 | cputime64_t busy_time; | |
107 | ||
108 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); | |
109 | busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user, | |
110 | kstat_cpu(cpu).cpustat.system); | |
e08f5f5b | 111 | |
8e677ce8 AC |
112 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq); |
113 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq); | |
114 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal); | |
115 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice); | |
e08f5f5b | 116 | |
8e677ce8 AC |
117 | idle_time = cputime64_sub(cur_wall_time, busy_time); |
118 | if (wall) | |
54c9a35d | 119 | *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time); |
e08f5f5b | 120 | |
54c9a35d | 121 | return (cputime64_t)jiffies_to_usecs(idle_time);; |
8e677ce8 AC |
122 | } |
123 | ||
124 | static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) | |
125 | { | |
126 | u64 idle_time = get_cpu_idle_time_us(cpu, wall); | |
127 | ||
128 | if (idle_time == -1ULL) | |
129 | return get_cpu_idle_time_jiffy(cpu, wall); | |
130 | ||
131 | return idle_time; | |
dac1c1a5 DJ |
132 | } |
133 | ||
a8d7c3bc EO |
134 | /* keep track of frequency transitions */ |
135 | static int | |
136 | dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val, | |
137 | void *data) | |
138 | { | |
139 | struct cpufreq_freqs *freq = data; | |
245b2e70 | 140 | struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cs_cpu_dbs_info, |
a8d7c3bc EO |
141 | freq->cpu); |
142 | ||
f407a08b AC |
143 | struct cpufreq_policy *policy; |
144 | ||
a8d7c3bc EO |
145 | if (!this_dbs_info->enable) |
146 | return 0; | |
147 | ||
f407a08b AC |
148 | policy = this_dbs_info->cur_policy; |
149 | ||
150 | /* | |
151 | * we only care if our internally tracked freq moves outside | |
152 | * the 'valid' ranges of freqency available to us otherwise | |
153 | * we do not change it | |
154 | */ | |
155 | if (this_dbs_info->requested_freq > policy->max | |
156 | || this_dbs_info->requested_freq < policy->min) | |
157 | this_dbs_info->requested_freq = freq->new; | |
a8d7c3bc EO |
158 | |
159 | return 0; | |
160 | } | |
161 | ||
162 | static struct notifier_block dbs_cpufreq_notifier_block = { | |
163 | .notifier_call = dbs_cpufreq_notifier | |
164 | }; | |
165 | ||
b9170836 | 166 | /************************** sysfs interface ************************/ |
49b015ce TR |
167 | static ssize_t show_sampling_rate_max(struct kobject *kobj, |
168 | struct attribute *attr, char *buf) | |
b9170836 | 169 | { |
4f4d1ad6 TR |
170 | printk_once(KERN_INFO "CPUFREQ: conservative sampling_rate_max " |
171 | "sysfs file is deprecated - used by: %s\n", current->comm); | |
cef9615a | 172 | return sprintf(buf, "%u\n", -1U); |
b9170836 DJ |
173 | } |
174 | ||
49b015ce TR |
175 | static ssize_t show_sampling_rate_min(struct kobject *kobj, |
176 | struct attribute *attr, char *buf) | |
b9170836 | 177 | { |
cef9615a | 178 | return sprintf(buf, "%u\n", min_sampling_rate); |
b9170836 DJ |
179 | } |
180 | ||
8e677ce8 | 181 | #define define_one_ro(_name) \ |
49b015ce | 182 | static struct global_attr _name = \ |
b9170836 DJ |
183 | __ATTR(_name, 0444, show_##_name, NULL) |
184 | ||
185 | define_one_ro(sampling_rate_max); | |
186 | define_one_ro(sampling_rate_min); | |
187 | ||
188 | /* cpufreq_conservative Governor Tunables */ | |
189 | #define show_one(file_name, object) \ | |
190 | static ssize_t show_##file_name \ | |
49b015ce | 191 | (struct kobject *kobj, struct attribute *attr, char *buf) \ |
b9170836 DJ |
192 | { \ |
193 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ | |
194 | } | |
195 | show_one(sampling_rate, sampling_rate); | |
196 | show_one(sampling_down_factor, sampling_down_factor); | |
197 | show_one(up_threshold, up_threshold); | |
198 | show_one(down_threshold, down_threshold); | |
001893cd | 199 | show_one(ignore_nice_load, ignore_nice); |
b9170836 DJ |
200 | show_one(freq_step, freq_step); |
201 | ||
49b015ce TR |
202 | /*** delete after deprecation time ***/ |
203 | #define DEPRECATION_MSG(file_name) \ | |
204 | printk_once(KERN_INFO "CPUFREQ: Per core conservative sysfs " \ | |
205 | "interface is deprecated - " #file_name "\n"); | |
206 | ||
207 | #define show_one_old(file_name) \ | |
208 | static ssize_t show_##file_name##_old \ | |
209 | (struct cpufreq_policy *unused, char *buf) \ | |
210 | { \ | |
211 | printk_once(KERN_INFO "CPUFREQ: Per core conservative sysfs " \ | |
212 | "interface is deprecated - " #file_name "\n"); \ | |
213 | return show_##file_name(NULL, NULL, buf); \ | |
214 | } | |
215 | show_one_old(sampling_rate); | |
216 | show_one_old(sampling_down_factor); | |
217 | show_one_old(up_threshold); | |
218 | show_one_old(down_threshold); | |
219 | show_one_old(ignore_nice_load); | |
220 | show_one_old(freq_step); | |
221 | show_one_old(sampling_rate_min); | |
222 | show_one_old(sampling_rate_max); | |
223 | ||
224 | #define define_one_ro_old(object, _name) \ | |
225 | static struct freq_attr object = \ | |
226 | __ATTR(_name, 0444, show_##_name##_old, NULL) | |
227 | ||
228 | define_one_ro_old(sampling_rate_min_old, sampling_rate_min); | |
229 | define_one_ro_old(sampling_rate_max_old, sampling_rate_max); | |
230 | ||
231 | /*** delete after deprecation time ***/ | |
232 | ||
233 | static ssize_t store_sampling_down_factor(struct kobject *a, | |
234 | struct attribute *b, | |
235 | const char *buf, size_t count) | |
b9170836 DJ |
236 | { |
237 | unsigned int input; | |
238 | int ret; | |
9acef487 | 239 | ret = sscanf(buf, "%u", &input); |
8e677ce8 | 240 | |
2c906b31 | 241 | if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) |
b9170836 DJ |
242 | return -EINVAL; |
243 | ||
3fc54d37 | 244 | mutex_lock(&dbs_mutex); |
b9170836 | 245 | dbs_tuners_ins.sampling_down_factor = input; |
3fc54d37 | 246 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
247 | |
248 | return count; | |
249 | } | |
250 | ||
49b015ce TR |
251 | static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b, |
252 | const char *buf, size_t count) | |
b9170836 DJ |
253 | { |
254 | unsigned int input; | |
255 | int ret; | |
9acef487 | 256 | ret = sscanf(buf, "%u", &input); |
b9170836 | 257 | |
8e677ce8 | 258 | if (ret != 1) |
b9170836 | 259 | return -EINVAL; |
8e677ce8 AC |
260 | |
261 | mutex_lock(&dbs_mutex); | |
cef9615a | 262 | dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate); |
3fc54d37 | 263 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
264 | |
265 | return count; | |
266 | } | |
267 | ||
49b015ce TR |
268 | static ssize_t store_up_threshold(struct kobject *a, struct attribute *b, |
269 | const char *buf, size_t count) | |
b9170836 DJ |
270 | { |
271 | unsigned int input; | |
272 | int ret; | |
9acef487 | 273 | ret = sscanf(buf, "%u", &input); |
b9170836 | 274 | |
3fc54d37 | 275 | mutex_lock(&dbs_mutex); |
9acef487 | 276 | if (ret != 1 || input > 100 || |
8e677ce8 | 277 | input <= dbs_tuners_ins.down_threshold) { |
3fc54d37 | 278 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
279 | return -EINVAL; |
280 | } | |
281 | ||
282 | dbs_tuners_ins.up_threshold = input; | |
3fc54d37 | 283 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
284 | |
285 | return count; | |
286 | } | |
287 | ||
49b015ce TR |
288 | static ssize_t store_down_threshold(struct kobject *a, struct attribute *b, |
289 | const char *buf, size_t count) | |
b9170836 DJ |
290 | { |
291 | unsigned int input; | |
292 | int ret; | |
9acef487 | 293 | ret = sscanf(buf, "%u", &input); |
b9170836 | 294 | |
3fc54d37 | 295 | mutex_lock(&dbs_mutex); |
8e677ce8 AC |
296 | /* cannot be lower than 11 otherwise freq will not fall */ |
297 | if (ret != 1 || input < 11 || input > 100 || | |
298 | input >= dbs_tuners_ins.up_threshold) { | |
3fc54d37 | 299 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
300 | return -EINVAL; |
301 | } | |
302 | ||
303 | dbs_tuners_ins.down_threshold = input; | |
3fc54d37 | 304 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
305 | |
306 | return count; | |
307 | } | |
308 | ||
49b015ce TR |
309 | static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b, |
310 | const char *buf, size_t count) | |
b9170836 DJ |
311 | { |
312 | unsigned int input; | |
313 | int ret; | |
314 | ||
315 | unsigned int j; | |
18a7247d DJ |
316 | |
317 | ret = sscanf(buf, "%u", &input); | |
318 | if (ret != 1) | |
b9170836 DJ |
319 | return -EINVAL; |
320 | ||
18a7247d | 321 | if (input > 1) |
b9170836 | 322 | input = 1; |
18a7247d | 323 | |
3fc54d37 | 324 | mutex_lock(&dbs_mutex); |
18a7247d | 325 | if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ |
3fc54d37 | 326 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
327 | return count; |
328 | } | |
329 | dbs_tuners_ins.ignore_nice = input; | |
330 | ||
8e677ce8 | 331 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 332 | for_each_online_cpu(j) { |
8e677ce8 | 333 | struct cpu_dbs_info_s *dbs_info; |
245b2e70 | 334 | dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
8e677ce8 AC |
335 | dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
336 | &dbs_info->prev_cpu_wall); | |
337 | if (dbs_tuners_ins.ignore_nice) | |
338 | dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
b9170836 | 339 | } |
3fc54d37 | 340 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
341 | |
342 | return count; | |
343 | } | |
344 | ||
49b015ce TR |
345 | static ssize_t store_freq_step(struct kobject *a, struct attribute *b, |
346 | const char *buf, size_t count) | |
b9170836 DJ |
347 | { |
348 | unsigned int input; | |
349 | int ret; | |
18a7247d | 350 | ret = sscanf(buf, "%u", &input); |
b9170836 | 351 | |
18a7247d | 352 | if (ret != 1) |
b9170836 DJ |
353 | return -EINVAL; |
354 | ||
18a7247d | 355 | if (input > 100) |
b9170836 | 356 | input = 100; |
18a7247d | 357 | |
b9170836 DJ |
358 | /* no need to test here if freq_step is zero as the user might actually |
359 | * want this, they would be crazy though :) */ | |
3fc54d37 | 360 | mutex_lock(&dbs_mutex); |
b9170836 | 361 | dbs_tuners_ins.freq_step = input; |
3fc54d37 | 362 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
363 | |
364 | return count; | |
365 | } | |
366 | ||
367 | #define define_one_rw(_name) \ | |
49b015ce | 368 | static struct global_attr _name = \ |
b9170836 DJ |
369 | __ATTR(_name, 0644, show_##_name, store_##_name) |
370 | ||
371 | define_one_rw(sampling_rate); | |
372 | define_one_rw(sampling_down_factor); | |
373 | define_one_rw(up_threshold); | |
374 | define_one_rw(down_threshold); | |
001893cd | 375 | define_one_rw(ignore_nice_load); |
b9170836 DJ |
376 | define_one_rw(freq_step); |
377 | ||
9acef487 | 378 | static struct attribute *dbs_attributes[] = { |
b9170836 DJ |
379 | &sampling_rate_max.attr, |
380 | &sampling_rate_min.attr, | |
381 | &sampling_rate.attr, | |
382 | &sampling_down_factor.attr, | |
383 | &up_threshold.attr, | |
384 | &down_threshold.attr, | |
001893cd | 385 | &ignore_nice_load.attr, |
b9170836 DJ |
386 | &freq_step.attr, |
387 | NULL | |
388 | }; | |
389 | ||
390 | static struct attribute_group dbs_attr_group = { | |
391 | .attrs = dbs_attributes, | |
392 | .name = "conservative", | |
393 | }; | |
394 | ||
49b015ce TR |
395 | /*** delete after deprecation time ***/ |
396 | ||
397 | #define write_one_old(file_name) \ | |
398 | static ssize_t store_##file_name##_old \ | |
399 | (struct cpufreq_policy *unused, const char *buf, size_t count) \ | |
400 | { \ | |
401 | printk_once(KERN_INFO "CPUFREQ: Per core conservative sysfs " \ | |
402 | "interface is deprecated - " #file_name "\n"); \ | |
403 | return store_##file_name(NULL, NULL, buf, count); \ | |
404 | } | |
405 | write_one_old(sampling_rate); | |
406 | write_one_old(sampling_down_factor); | |
407 | write_one_old(up_threshold); | |
408 | write_one_old(down_threshold); | |
409 | write_one_old(ignore_nice_load); | |
410 | write_one_old(freq_step); | |
411 | ||
412 | #define define_one_rw_old(object, _name) \ | |
413 | static struct freq_attr object = \ | |
414 | __ATTR(_name, 0644, show_##_name##_old, store_##_name##_old) | |
415 | ||
416 | define_one_rw_old(sampling_rate_old, sampling_rate); | |
417 | define_one_rw_old(sampling_down_factor_old, sampling_down_factor); | |
418 | define_one_rw_old(up_threshold_old, up_threshold); | |
419 | define_one_rw_old(down_threshold_old, down_threshold); | |
420 | define_one_rw_old(ignore_nice_load_old, ignore_nice_load); | |
421 | define_one_rw_old(freq_step_old, freq_step); | |
422 | ||
423 | static struct attribute *dbs_attributes_old[] = { | |
424 | &sampling_rate_max_old.attr, | |
425 | &sampling_rate_min_old.attr, | |
426 | &sampling_rate_old.attr, | |
427 | &sampling_down_factor_old.attr, | |
428 | &up_threshold_old.attr, | |
429 | &down_threshold_old.attr, | |
430 | &ignore_nice_load_old.attr, | |
431 | &freq_step_old.attr, | |
432 | NULL | |
433 | }; | |
434 | ||
435 | static struct attribute_group dbs_attr_group_old = { | |
436 | .attrs = dbs_attributes_old, | |
437 | .name = "conservative", | |
438 | }; | |
439 | ||
440 | /*** delete after deprecation time ***/ | |
441 | ||
b9170836 DJ |
442 | /************************** sysfs end ************************/ |
443 | ||
8e677ce8 | 444 | static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) |
b9170836 | 445 | { |
8e677ce8 | 446 | unsigned int load = 0; |
f068c04b | 447 | unsigned int freq_target; |
b9170836 | 448 | |
8e677ce8 AC |
449 | struct cpufreq_policy *policy; |
450 | unsigned int j; | |
b9170836 | 451 | |
08a28e2e AC |
452 | policy = this_dbs_info->cur_policy; |
453 | ||
18a7247d | 454 | /* |
8e677ce8 AC |
455 | * Every sampling_rate, we check, if current idle time is less |
456 | * than 20% (default), then we try to increase frequency | |
457 | * Every sampling_rate*sampling_down_factor, we check, if current | |
458 | * idle time is more than 80%, then we try to decrease frequency | |
b9170836 | 459 | * |
18a7247d DJ |
460 | * Any frequency increase takes it to the maximum frequency. |
461 | * Frequency reduction happens at minimum steps of | |
8e677ce8 | 462 | * 5% (default) of maximum frequency |
b9170836 DJ |
463 | */ |
464 | ||
8e677ce8 AC |
465 | /* Get Absolute Load */ |
466 | for_each_cpu(j, policy->cpus) { | |
467 | struct cpu_dbs_info_s *j_dbs_info; | |
468 | cputime64_t cur_wall_time, cur_idle_time; | |
469 | unsigned int idle_time, wall_time; | |
b9170836 | 470 | |
245b2e70 | 471 | j_dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
8e677ce8 AC |
472 | |
473 | cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); | |
474 | ||
475 | wall_time = (unsigned int) cputime64_sub(cur_wall_time, | |
476 | j_dbs_info->prev_cpu_wall); | |
477 | j_dbs_info->prev_cpu_wall = cur_wall_time; | |
08a28e2e | 478 | |
8e677ce8 AC |
479 | idle_time = (unsigned int) cputime64_sub(cur_idle_time, |
480 | j_dbs_info->prev_cpu_idle); | |
481 | j_dbs_info->prev_cpu_idle = cur_idle_time; | |
b9170836 | 482 | |
8e677ce8 AC |
483 | if (dbs_tuners_ins.ignore_nice) { |
484 | cputime64_t cur_nice; | |
485 | unsigned long cur_nice_jiffies; | |
486 | ||
487 | cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice, | |
488 | j_dbs_info->prev_cpu_nice); | |
489 | /* | |
490 | * Assumption: nice time between sampling periods will | |
491 | * be less than 2^32 jiffies for 32 bit sys | |
492 | */ | |
493 | cur_nice_jiffies = (unsigned long) | |
494 | cputime64_to_jiffies64(cur_nice); | |
495 | ||
496 | j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
497 | idle_time += jiffies_to_usecs(cur_nice_jiffies); | |
498 | } | |
499 | ||
500 | if (unlikely(!wall_time || wall_time < idle_time)) | |
501 | continue; | |
502 | ||
503 | load = 100 * (wall_time - idle_time) / wall_time; | |
504 | } | |
505 | ||
506 | /* | |
507 | * break out if we 'cannot' reduce the speed as the user might | |
508 | * want freq_step to be zero | |
509 | */ | |
510 | if (dbs_tuners_ins.freq_step == 0) | |
511 | return; | |
b9170836 | 512 | |
8e677ce8 AC |
513 | /* Check for frequency increase */ |
514 | if (load > dbs_tuners_ins.up_threshold) { | |
a159b827 | 515 | this_dbs_info->down_skip = 0; |
790d76fa | 516 | |
b9170836 | 517 | /* if we are already at full speed then break out early */ |
a159b827 | 518 | if (this_dbs_info->requested_freq == policy->max) |
b9170836 | 519 | return; |
18a7247d | 520 | |
f068c04b | 521 | freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100; |
b9170836 DJ |
522 | |
523 | /* max freq cannot be less than 100. But who knows.... */ | |
f068c04b DJ |
524 | if (unlikely(freq_target == 0)) |
525 | freq_target = 5; | |
18a7247d | 526 | |
f068c04b | 527 | this_dbs_info->requested_freq += freq_target; |
a159b827 AC |
528 | if (this_dbs_info->requested_freq > policy->max) |
529 | this_dbs_info->requested_freq = policy->max; | |
b9170836 | 530 | |
a159b827 | 531 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
b9170836 | 532 | CPUFREQ_RELATION_H); |
b9170836 DJ |
533 | return; |
534 | } | |
535 | ||
8e677ce8 AC |
536 | /* |
537 | * The optimal frequency is the frequency that is the lowest that | |
538 | * can support the current CPU usage without triggering the up | |
539 | * policy. To be safe, we focus 10 points under the threshold. | |
540 | */ | |
541 | if (load < (dbs_tuners_ins.down_threshold - 10)) { | |
f068c04b | 542 | freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100; |
b9170836 | 543 | |
f068c04b | 544 | this_dbs_info->requested_freq -= freq_target; |
a159b827 AC |
545 | if (this_dbs_info->requested_freq < policy->min) |
546 | this_dbs_info->requested_freq = policy->min; | |
b9170836 | 547 | |
8e677ce8 AC |
548 | /* |
549 | * if we cannot reduce the frequency anymore, break out early | |
550 | */ | |
551 | if (policy->cur == policy->min) | |
552 | return; | |
553 | ||
a159b827 | 554 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
2c906b31 | 555 | CPUFREQ_RELATION_H); |
b9170836 DJ |
556 | return; |
557 | } | |
558 | } | |
559 | ||
c4028958 | 560 | static void do_dbs_timer(struct work_struct *work) |
18a7247d | 561 | { |
8e677ce8 AC |
562 | struct cpu_dbs_info_s *dbs_info = |
563 | container_of(work, struct cpu_dbs_info_s, work.work); | |
564 | unsigned int cpu = dbs_info->cpu; | |
565 | ||
566 | /* We want all CPUs to do sampling nearly on same jiffy */ | |
567 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
568 | ||
569 | delay -= jiffies % delay; | |
570 | ||
ee88415c | 571 | mutex_lock(&dbs_info->timer_mutex); |
8e677ce8 AC |
572 | |
573 | dbs_check_cpu(dbs_info); | |
574 | ||
575 | queue_delayed_work_on(cpu, kconservative_wq, &dbs_info->work, delay); | |
ee88415c | 576 | mutex_unlock(&dbs_info->timer_mutex); |
18a7247d | 577 | } |
b9170836 | 578 | |
8e677ce8 | 579 | static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) |
b9170836 | 580 | { |
8e677ce8 AC |
581 | /* We want all CPUs to do sampling nearly on same jiffy */ |
582 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
583 | delay -= jiffies % delay; | |
584 | ||
585 | dbs_info->enable = 1; | |
586 | INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); | |
587 | queue_delayed_work_on(dbs_info->cpu, kconservative_wq, &dbs_info->work, | |
588 | delay); | |
b9170836 DJ |
589 | } |
590 | ||
8e677ce8 | 591 | static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) |
b9170836 | 592 | { |
8e677ce8 | 593 | dbs_info->enable = 0; |
b253d2b2 | 594 | cancel_delayed_work_sync(&dbs_info->work); |
b9170836 DJ |
595 | } |
596 | ||
597 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, | |
598 | unsigned int event) | |
599 | { | |
600 | unsigned int cpu = policy->cpu; | |
601 | struct cpu_dbs_info_s *this_dbs_info; | |
602 | unsigned int j; | |
914f7c31 | 603 | int rc; |
b9170836 | 604 | |
245b2e70 | 605 | this_dbs_info = &per_cpu(cs_cpu_dbs_info, cpu); |
b9170836 DJ |
606 | |
607 | switch (event) { | |
608 | case CPUFREQ_GOV_START: | |
18a7247d | 609 | if ((!cpu_online(cpu)) || (!policy->cur)) |
b9170836 DJ |
610 | return -EINVAL; |
611 | ||
3fc54d37 | 612 | mutex_lock(&dbs_mutex); |
914f7c31 | 613 | |
49b015ce | 614 | rc = sysfs_create_group(&policy->kobj, &dbs_attr_group_old); |
914f7c31 JG |
615 | if (rc) { |
616 | mutex_unlock(&dbs_mutex); | |
617 | return rc; | |
618 | } | |
619 | ||
835481d9 | 620 | for_each_cpu(j, policy->cpus) { |
b9170836 | 621 | struct cpu_dbs_info_s *j_dbs_info; |
245b2e70 | 622 | j_dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
b9170836 | 623 | j_dbs_info->cur_policy = policy; |
18a7247d | 624 | |
8e677ce8 AC |
625 | j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
626 | &j_dbs_info->prev_cpu_wall); | |
627 | if (dbs_tuners_ins.ignore_nice) { | |
628 | j_dbs_info->prev_cpu_nice = | |
629 | kstat_cpu(j).cpustat.nice; | |
630 | } | |
b9170836 | 631 | } |
a159b827 AC |
632 | this_dbs_info->down_skip = 0; |
633 | this_dbs_info->requested_freq = policy->cur; | |
914f7c31 | 634 | |
ee88415c | 635 | mutex_init(&this_dbs_info->timer_mutex); |
b9170836 DJ |
636 | dbs_enable++; |
637 | /* | |
638 | * Start the timerschedule work, when this governor | |
639 | * is used for first time | |
640 | */ | |
641 | if (dbs_enable == 1) { | |
642 | unsigned int latency; | |
643 | /* policy latency is in nS. Convert it to uS first */ | |
2c906b31 AC |
644 | latency = policy->cpuinfo.transition_latency / 1000; |
645 | if (latency == 0) | |
646 | latency = 1; | |
b9170836 | 647 | |
49b015ce TR |
648 | rc = sysfs_create_group(cpufreq_global_kobject, |
649 | &dbs_attr_group); | |
650 | if (rc) { | |
651 | mutex_unlock(&dbs_mutex); | |
652 | return rc; | |
653 | } | |
654 | ||
cef9615a TR |
655 | /* |
656 | * conservative does not implement micro like ondemand | |
657 | * governor, thus we are bound to jiffes/HZ | |
658 | */ | |
659 | min_sampling_rate = | |
660 | MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); | |
661 | /* Bring kernel and HW constraints together */ | |
662 | min_sampling_rate = max(min_sampling_rate, | |
663 | MIN_LATENCY_MULTIPLIER * latency); | |
664 | dbs_tuners_ins.sampling_rate = | |
665 | max(min_sampling_rate, | |
666 | latency * LATENCY_MULTIPLIER); | |
b9170836 | 667 | |
a8d7c3bc EO |
668 | cpufreq_register_notifier( |
669 | &dbs_cpufreq_notifier_block, | |
670 | CPUFREQ_TRANSITION_NOTIFIER); | |
b9170836 | 671 | } |
3fc54d37 | 672 | mutex_unlock(&dbs_mutex); |
8e677ce8 | 673 | |
7d26e2d5 | 674 | dbs_timer_init(this_dbs_info); |
675 | ||
b9170836 DJ |
676 | break; |
677 | ||
678 | case CPUFREQ_GOV_STOP: | |
8e677ce8 | 679 | dbs_timer_exit(this_dbs_info); |
7d26e2d5 | 680 | |
681 | mutex_lock(&dbs_mutex); | |
49b015ce | 682 | sysfs_remove_group(&policy->kobj, &dbs_attr_group_old); |
b9170836 | 683 | dbs_enable--; |
ee88415c | 684 | mutex_destroy(&this_dbs_info->timer_mutex); |
8e677ce8 | 685 | |
b9170836 DJ |
686 | /* |
687 | * Stop the timerschedule work, when this governor | |
688 | * is used for first time | |
689 | */ | |
8e677ce8 | 690 | if (dbs_enable == 0) |
a8d7c3bc EO |
691 | cpufreq_unregister_notifier( |
692 | &dbs_cpufreq_notifier_block, | |
693 | CPUFREQ_TRANSITION_NOTIFIER); | |
a8d7c3bc | 694 | |
3fc54d37 | 695 | mutex_unlock(&dbs_mutex); |
49b015ce TR |
696 | if (!dbs_enable) |
697 | sysfs_remove_group(cpufreq_global_kobject, | |
698 | &dbs_attr_group); | |
b9170836 DJ |
699 | |
700 | break; | |
701 | ||
702 | case CPUFREQ_GOV_LIMITS: | |
ee88415c | 703 | mutex_lock(&this_dbs_info->timer_mutex); |
b9170836 DJ |
704 | if (policy->max < this_dbs_info->cur_policy->cur) |
705 | __cpufreq_driver_target( | |
706 | this_dbs_info->cur_policy, | |
18a7247d | 707 | policy->max, CPUFREQ_RELATION_H); |
b9170836 DJ |
708 | else if (policy->min > this_dbs_info->cur_policy->cur) |
709 | __cpufreq_driver_target( | |
710 | this_dbs_info->cur_policy, | |
18a7247d | 711 | policy->min, CPUFREQ_RELATION_L); |
ee88415c | 712 | mutex_unlock(&this_dbs_info->timer_mutex); |
8e677ce8 | 713 | |
b9170836 DJ |
714 | break; |
715 | } | |
716 | return 0; | |
717 | } | |
718 | ||
c4d14bc0 SW |
719 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
720 | static | |
721 | #endif | |
1c256245 TR |
722 | struct cpufreq_governor cpufreq_gov_conservative = { |
723 | .name = "conservative", | |
724 | .governor = cpufreq_governor_dbs, | |
725 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, | |
726 | .owner = THIS_MODULE, | |
b9170836 DJ |
727 | }; |
728 | ||
729 | static int __init cpufreq_gov_dbs_init(void) | |
730 | { | |
8e677ce8 AC |
731 | int err; |
732 | ||
733 | kconservative_wq = create_workqueue("kconservative"); | |
734 | if (!kconservative_wq) { | |
735 | printk(KERN_ERR "Creation of kconservative failed\n"); | |
736 | return -EFAULT; | |
737 | } | |
738 | ||
739 | err = cpufreq_register_governor(&cpufreq_gov_conservative); | |
740 | if (err) | |
741 | destroy_workqueue(kconservative_wq); | |
742 | ||
743 | return err; | |
b9170836 DJ |
744 | } |
745 | ||
746 | static void __exit cpufreq_gov_dbs_exit(void) | |
747 | { | |
1c256245 | 748 | cpufreq_unregister_governor(&cpufreq_gov_conservative); |
8e677ce8 | 749 | destroy_workqueue(kconservative_wq); |
b9170836 DJ |
750 | } |
751 | ||
752 | ||
11a80a9c | 753 | MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>"); |
9acef487 | 754 | MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for " |
b9170836 DJ |
755 | "Low Latency Frequency Transition capable processors " |
756 | "optimised for use in a battery environment"); | |
9acef487 | 757 | MODULE_LICENSE("GPL"); |
b9170836 | 758 | |
6915719b JW |
759 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
760 | fs_initcall(cpufreq_gov_dbs_init); | |
761 | #else | |
b9170836 | 762 | module_init(cpufreq_gov_dbs_init); |
6915719b | 763 | #endif |
b9170836 | 764 | module_exit(cpufreq_gov_dbs_exit); |