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 | ||
6dad2a29 BP |
181 | define_one_global_ro(sampling_rate_max); |
182 | define_one_global_ro(sampling_rate_min); | |
b9170836 DJ |
183 | |
184 | /* cpufreq_conservative Governor Tunables */ | |
185 | #define show_one(file_name, object) \ | |
186 | static ssize_t show_##file_name \ | |
49b015ce | 187 | (struct kobject *kobj, struct attribute *attr, char *buf) \ |
b9170836 DJ |
188 | { \ |
189 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ | |
190 | } | |
191 | show_one(sampling_rate, sampling_rate); | |
192 | show_one(sampling_down_factor, sampling_down_factor); | |
193 | show_one(up_threshold, up_threshold); | |
194 | show_one(down_threshold, down_threshold); | |
001893cd | 195 | show_one(ignore_nice_load, ignore_nice); |
b9170836 DJ |
196 | show_one(freq_step, freq_step); |
197 | ||
49b015ce TR |
198 | /*** delete after deprecation time ***/ |
199 | #define DEPRECATION_MSG(file_name) \ | |
200 | printk_once(KERN_INFO "CPUFREQ: Per core conservative sysfs " \ | |
201 | "interface is deprecated - " #file_name "\n"); | |
202 | ||
203 | #define show_one_old(file_name) \ | |
204 | static ssize_t show_##file_name##_old \ | |
205 | (struct cpufreq_policy *unused, char *buf) \ | |
206 | { \ | |
207 | printk_once(KERN_INFO "CPUFREQ: Per core conservative sysfs " \ | |
208 | "interface is deprecated - " #file_name "\n"); \ | |
209 | return show_##file_name(NULL, NULL, buf); \ | |
210 | } | |
211 | show_one_old(sampling_rate); | |
212 | show_one_old(sampling_down_factor); | |
213 | show_one_old(up_threshold); | |
214 | show_one_old(down_threshold); | |
215 | show_one_old(ignore_nice_load); | |
216 | show_one_old(freq_step); | |
217 | show_one_old(sampling_rate_min); | |
218 | show_one_old(sampling_rate_max); | |
219 | ||
6dad2a29 BP |
220 | cpufreq_freq_attr_ro_old(sampling_rate_min); |
221 | cpufreq_freq_attr_ro_old(sampling_rate_max); | |
49b015ce TR |
222 | |
223 | /*** delete after deprecation time ***/ | |
224 | ||
225 | static ssize_t store_sampling_down_factor(struct kobject *a, | |
226 | struct attribute *b, | |
227 | const char *buf, size_t count) | |
b9170836 DJ |
228 | { |
229 | unsigned int input; | |
230 | int ret; | |
9acef487 | 231 | ret = sscanf(buf, "%u", &input); |
8e677ce8 | 232 | |
2c906b31 | 233 | if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) |
b9170836 DJ |
234 | return -EINVAL; |
235 | ||
3fc54d37 | 236 | mutex_lock(&dbs_mutex); |
b9170836 | 237 | dbs_tuners_ins.sampling_down_factor = input; |
3fc54d37 | 238 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
239 | |
240 | return count; | |
241 | } | |
242 | ||
49b015ce TR |
243 | static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b, |
244 | const char *buf, size_t count) | |
b9170836 DJ |
245 | { |
246 | unsigned int input; | |
247 | int ret; | |
9acef487 | 248 | ret = sscanf(buf, "%u", &input); |
b9170836 | 249 | |
8e677ce8 | 250 | if (ret != 1) |
b9170836 | 251 | return -EINVAL; |
8e677ce8 AC |
252 | |
253 | mutex_lock(&dbs_mutex); | |
cef9615a | 254 | dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate); |
3fc54d37 | 255 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
256 | |
257 | return count; | |
258 | } | |
259 | ||
49b015ce TR |
260 | static ssize_t store_up_threshold(struct kobject *a, struct attribute *b, |
261 | const char *buf, size_t count) | |
b9170836 DJ |
262 | { |
263 | unsigned int input; | |
264 | int ret; | |
9acef487 | 265 | ret = sscanf(buf, "%u", &input); |
b9170836 | 266 | |
3fc54d37 | 267 | mutex_lock(&dbs_mutex); |
9acef487 | 268 | if (ret != 1 || input > 100 || |
8e677ce8 | 269 | input <= dbs_tuners_ins.down_threshold) { |
3fc54d37 | 270 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
271 | return -EINVAL; |
272 | } | |
273 | ||
274 | dbs_tuners_ins.up_threshold = input; | |
3fc54d37 | 275 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
276 | |
277 | return count; | |
278 | } | |
279 | ||
49b015ce TR |
280 | static ssize_t store_down_threshold(struct kobject *a, struct attribute *b, |
281 | const char *buf, size_t count) | |
b9170836 DJ |
282 | { |
283 | unsigned int input; | |
284 | int ret; | |
9acef487 | 285 | ret = sscanf(buf, "%u", &input); |
b9170836 | 286 | |
3fc54d37 | 287 | mutex_lock(&dbs_mutex); |
8e677ce8 AC |
288 | /* cannot be lower than 11 otherwise freq will not fall */ |
289 | if (ret != 1 || input < 11 || input > 100 || | |
290 | input >= dbs_tuners_ins.up_threshold) { | |
3fc54d37 | 291 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
292 | return -EINVAL; |
293 | } | |
294 | ||
295 | dbs_tuners_ins.down_threshold = input; | |
3fc54d37 | 296 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
297 | |
298 | return count; | |
299 | } | |
300 | ||
49b015ce TR |
301 | static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b, |
302 | const char *buf, size_t count) | |
b9170836 DJ |
303 | { |
304 | unsigned int input; | |
305 | int ret; | |
306 | ||
307 | unsigned int j; | |
18a7247d DJ |
308 | |
309 | ret = sscanf(buf, "%u", &input); | |
310 | if (ret != 1) | |
b9170836 DJ |
311 | return -EINVAL; |
312 | ||
18a7247d | 313 | if (input > 1) |
b9170836 | 314 | input = 1; |
18a7247d | 315 | |
3fc54d37 | 316 | mutex_lock(&dbs_mutex); |
18a7247d | 317 | if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ |
3fc54d37 | 318 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
319 | return count; |
320 | } | |
321 | dbs_tuners_ins.ignore_nice = input; | |
322 | ||
8e677ce8 | 323 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 324 | for_each_online_cpu(j) { |
8e677ce8 | 325 | struct cpu_dbs_info_s *dbs_info; |
245b2e70 | 326 | dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
8e677ce8 AC |
327 | dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
328 | &dbs_info->prev_cpu_wall); | |
329 | if (dbs_tuners_ins.ignore_nice) | |
330 | dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
b9170836 | 331 | } |
3fc54d37 | 332 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
333 | |
334 | return count; | |
335 | } | |
336 | ||
49b015ce TR |
337 | static ssize_t store_freq_step(struct kobject *a, struct attribute *b, |
338 | const char *buf, size_t count) | |
b9170836 DJ |
339 | { |
340 | unsigned int input; | |
341 | int ret; | |
18a7247d | 342 | ret = sscanf(buf, "%u", &input); |
b9170836 | 343 | |
18a7247d | 344 | if (ret != 1) |
b9170836 DJ |
345 | return -EINVAL; |
346 | ||
18a7247d | 347 | if (input > 100) |
b9170836 | 348 | input = 100; |
18a7247d | 349 | |
b9170836 DJ |
350 | /* no need to test here if freq_step is zero as the user might actually |
351 | * want this, they would be crazy though :) */ | |
3fc54d37 | 352 | mutex_lock(&dbs_mutex); |
b9170836 | 353 | dbs_tuners_ins.freq_step = input; |
3fc54d37 | 354 | mutex_unlock(&dbs_mutex); |
b9170836 DJ |
355 | |
356 | return count; | |
357 | } | |
358 | ||
6dad2a29 BP |
359 | define_one_global_rw(sampling_rate); |
360 | define_one_global_rw(sampling_down_factor); | |
361 | define_one_global_rw(up_threshold); | |
362 | define_one_global_rw(down_threshold); | |
363 | define_one_global_rw(ignore_nice_load); | |
364 | define_one_global_rw(freq_step); | |
b9170836 | 365 | |
9acef487 | 366 | static struct attribute *dbs_attributes[] = { |
b9170836 DJ |
367 | &sampling_rate_max.attr, |
368 | &sampling_rate_min.attr, | |
369 | &sampling_rate.attr, | |
370 | &sampling_down_factor.attr, | |
371 | &up_threshold.attr, | |
372 | &down_threshold.attr, | |
001893cd | 373 | &ignore_nice_load.attr, |
b9170836 DJ |
374 | &freq_step.attr, |
375 | NULL | |
376 | }; | |
377 | ||
378 | static struct attribute_group dbs_attr_group = { | |
379 | .attrs = dbs_attributes, | |
380 | .name = "conservative", | |
381 | }; | |
382 | ||
49b015ce TR |
383 | /*** delete after deprecation time ***/ |
384 | ||
385 | #define write_one_old(file_name) \ | |
386 | static ssize_t store_##file_name##_old \ | |
387 | (struct cpufreq_policy *unused, const char *buf, size_t count) \ | |
388 | { \ | |
389 | printk_once(KERN_INFO "CPUFREQ: Per core conservative sysfs " \ | |
390 | "interface is deprecated - " #file_name "\n"); \ | |
391 | return store_##file_name(NULL, NULL, buf, count); \ | |
392 | } | |
393 | write_one_old(sampling_rate); | |
394 | write_one_old(sampling_down_factor); | |
395 | write_one_old(up_threshold); | |
396 | write_one_old(down_threshold); | |
397 | write_one_old(ignore_nice_load); | |
398 | write_one_old(freq_step); | |
399 | ||
6dad2a29 BP |
400 | cpufreq_freq_attr_rw_old(sampling_rate); |
401 | cpufreq_freq_attr_rw_old(sampling_down_factor); | |
402 | cpufreq_freq_attr_rw_old(up_threshold); | |
403 | cpufreq_freq_attr_rw_old(down_threshold); | |
404 | cpufreq_freq_attr_rw_old(ignore_nice_load); | |
405 | cpufreq_freq_attr_rw_old(freq_step); | |
49b015ce TR |
406 | |
407 | static struct attribute *dbs_attributes_old[] = { | |
408 | &sampling_rate_max_old.attr, | |
409 | &sampling_rate_min_old.attr, | |
410 | &sampling_rate_old.attr, | |
411 | &sampling_down_factor_old.attr, | |
412 | &up_threshold_old.attr, | |
413 | &down_threshold_old.attr, | |
414 | &ignore_nice_load_old.attr, | |
415 | &freq_step_old.attr, | |
416 | NULL | |
417 | }; | |
418 | ||
419 | static struct attribute_group dbs_attr_group_old = { | |
420 | .attrs = dbs_attributes_old, | |
421 | .name = "conservative", | |
422 | }; | |
423 | ||
424 | /*** delete after deprecation time ***/ | |
425 | ||
b9170836 DJ |
426 | /************************** sysfs end ************************/ |
427 | ||
8e677ce8 | 428 | static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) |
b9170836 | 429 | { |
8e677ce8 | 430 | unsigned int load = 0; |
fd187aaf | 431 | unsigned int max_load = 0; |
f068c04b | 432 | unsigned int freq_target; |
b9170836 | 433 | |
8e677ce8 AC |
434 | struct cpufreq_policy *policy; |
435 | unsigned int j; | |
b9170836 | 436 | |
08a28e2e AC |
437 | policy = this_dbs_info->cur_policy; |
438 | ||
18a7247d | 439 | /* |
8e677ce8 AC |
440 | * Every sampling_rate, we check, if current idle time is less |
441 | * than 20% (default), then we try to increase frequency | |
442 | * Every sampling_rate*sampling_down_factor, we check, if current | |
443 | * idle time is more than 80%, then we try to decrease frequency | |
b9170836 | 444 | * |
18a7247d DJ |
445 | * Any frequency increase takes it to the maximum frequency. |
446 | * Frequency reduction happens at minimum steps of | |
8e677ce8 | 447 | * 5% (default) of maximum frequency |
b9170836 DJ |
448 | */ |
449 | ||
8e677ce8 AC |
450 | /* Get Absolute Load */ |
451 | for_each_cpu(j, policy->cpus) { | |
452 | struct cpu_dbs_info_s *j_dbs_info; | |
453 | cputime64_t cur_wall_time, cur_idle_time; | |
454 | unsigned int idle_time, wall_time; | |
b9170836 | 455 | |
245b2e70 | 456 | j_dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
8e677ce8 AC |
457 | |
458 | cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); | |
459 | ||
460 | wall_time = (unsigned int) cputime64_sub(cur_wall_time, | |
461 | j_dbs_info->prev_cpu_wall); | |
462 | j_dbs_info->prev_cpu_wall = cur_wall_time; | |
08a28e2e | 463 | |
8e677ce8 AC |
464 | idle_time = (unsigned int) cputime64_sub(cur_idle_time, |
465 | j_dbs_info->prev_cpu_idle); | |
466 | j_dbs_info->prev_cpu_idle = cur_idle_time; | |
b9170836 | 467 | |
8e677ce8 AC |
468 | if (dbs_tuners_ins.ignore_nice) { |
469 | cputime64_t cur_nice; | |
470 | unsigned long cur_nice_jiffies; | |
471 | ||
472 | cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice, | |
473 | j_dbs_info->prev_cpu_nice); | |
474 | /* | |
475 | * Assumption: nice time between sampling periods will | |
476 | * be less than 2^32 jiffies for 32 bit sys | |
477 | */ | |
478 | cur_nice_jiffies = (unsigned long) | |
479 | cputime64_to_jiffies64(cur_nice); | |
480 | ||
481 | j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
482 | idle_time += jiffies_to_usecs(cur_nice_jiffies); | |
483 | } | |
484 | ||
485 | if (unlikely(!wall_time || wall_time < idle_time)) | |
486 | continue; | |
487 | ||
488 | load = 100 * (wall_time - idle_time) / wall_time; | |
fd187aaf DB |
489 | |
490 | if (load > max_load) | |
491 | max_load = load; | |
8e677ce8 AC |
492 | } |
493 | ||
494 | /* | |
495 | * break out if we 'cannot' reduce the speed as the user might | |
496 | * want freq_step to be zero | |
497 | */ | |
498 | if (dbs_tuners_ins.freq_step == 0) | |
499 | return; | |
b9170836 | 500 | |
8e677ce8 | 501 | /* Check for frequency increase */ |
fd187aaf | 502 | if (max_load > dbs_tuners_ins.up_threshold) { |
a159b827 | 503 | this_dbs_info->down_skip = 0; |
790d76fa | 504 | |
b9170836 | 505 | /* if we are already at full speed then break out early */ |
a159b827 | 506 | if (this_dbs_info->requested_freq == policy->max) |
b9170836 | 507 | return; |
18a7247d | 508 | |
f068c04b | 509 | freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100; |
b9170836 DJ |
510 | |
511 | /* max freq cannot be less than 100. But who knows.... */ | |
f068c04b DJ |
512 | if (unlikely(freq_target == 0)) |
513 | freq_target = 5; | |
18a7247d | 514 | |
f068c04b | 515 | this_dbs_info->requested_freq += freq_target; |
a159b827 AC |
516 | if (this_dbs_info->requested_freq > policy->max) |
517 | this_dbs_info->requested_freq = policy->max; | |
b9170836 | 518 | |
a159b827 | 519 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
b9170836 | 520 | CPUFREQ_RELATION_H); |
b9170836 DJ |
521 | return; |
522 | } | |
523 | ||
8e677ce8 AC |
524 | /* |
525 | * The optimal frequency is the frequency that is the lowest that | |
526 | * can support the current CPU usage without triggering the up | |
527 | * policy. To be safe, we focus 10 points under the threshold. | |
528 | */ | |
fd187aaf | 529 | if (max_load < (dbs_tuners_ins.down_threshold - 10)) { |
f068c04b | 530 | freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100; |
b9170836 | 531 | |
f068c04b | 532 | this_dbs_info->requested_freq -= freq_target; |
a159b827 AC |
533 | if (this_dbs_info->requested_freq < policy->min) |
534 | this_dbs_info->requested_freq = policy->min; | |
b9170836 | 535 | |
8e677ce8 AC |
536 | /* |
537 | * if we cannot reduce the frequency anymore, break out early | |
538 | */ | |
539 | if (policy->cur == policy->min) | |
540 | return; | |
541 | ||
a159b827 | 542 | __cpufreq_driver_target(policy, this_dbs_info->requested_freq, |
2c906b31 | 543 | CPUFREQ_RELATION_H); |
b9170836 DJ |
544 | return; |
545 | } | |
546 | } | |
547 | ||
c4028958 | 548 | static void do_dbs_timer(struct work_struct *work) |
18a7247d | 549 | { |
8e677ce8 AC |
550 | struct cpu_dbs_info_s *dbs_info = |
551 | container_of(work, struct cpu_dbs_info_s, work.work); | |
552 | unsigned int cpu = dbs_info->cpu; | |
553 | ||
554 | /* We want all CPUs to do sampling nearly on same jiffy */ | |
555 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
556 | ||
557 | delay -= jiffies % delay; | |
558 | ||
ee88415c | 559 | mutex_lock(&dbs_info->timer_mutex); |
8e677ce8 AC |
560 | |
561 | dbs_check_cpu(dbs_info); | |
562 | ||
563 | queue_delayed_work_on(cpu, kconservative_wq, &dbs_info->work, delay); | |
ee88415c | 564 | mutex_unlock(&dbs_info->timer_mutex); |
18a7247d | 565 | } |
b9170836 | 566 | |
8e677ce8 | 567 | static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) |
b9170836 | 568 | { |
8e677ce8 AC |
569 | /* We want all CPUs to do sampling nearly on same jiffy */ |
570 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
571 | delay -= jiffies % delay; | |
572 | ||
573 | dbs_info->enable = 1; | |
574 | INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); | |
575 | queue_delayed_work_on(dbs_info->cpu, kconservative_wq, &dbs_info->work, | |
576 | delay); | |
b9170836 DJ |
577 | } |
578 | ||
8e677ce8 | 579 | static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) |
b9170836 | 580 | { |
8e677ce8 | 581 | dbs_info->enable = 0; |
b253d2b2 | 582 | cancel_delayed_work_sync(&dbs_info->work); |
b9170836 DJ |
583 | } |
584 | ||
585 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, | |
586 | unsigned int event) | |
587 | { | |
588 | unsigned int cpu = policy->cpu; | |
589 | struct cpu_dbs_info_s *this_dbs_info; | |
590 | unsigned int j; | |
914f7c31 | 591 | int rc; |
b9170836 | 592 | |
245b2e70 | 593 | this_dbs_info = &per_cpu(cs_cpu_dbs_info, cpu); |
b9170836 DJ |
594 | |
595 | switch (event) { | |
596 | case CPUFREQ_GOV_START: | |
18a7247d | 597 | if ((!cpu_online(cpu)) || (!policy->cur)) |
b9170836 DJ |
598 | return -EINVAL; |
599 | ||
3fc54d37 | 600 | mutex_lock(&dbs_mutex); |
914f7c31 | 601 | |
49b015ce | 602 | rc = sysfs_create_group(&policy->kobj, &dbs_attr_group_old); |
914f7c31 JG |
603 | if (rc) { |
604 | mutex_unlock(&dbs_mutex); | |
605 | return rc; | |
606 | } | |
607 | ||
835481d9 | 608 | for_each_cpu(j, policy->cpus) { |
b9170836 | 609 | struct cpu_dbs_info_s *j_dbs_info; |
245b2e70 | 610 | j_dbs_info = &per_cpu(cs_cpu_dbs_info, j); |
b9170836 | 611 | j_dbs_info->cur_policy = policy; |
18a7247d | 612 | |
8e677ce8 AC |
613 | j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
614 | &j_dbs_info->prev_cpu_wall); | |
615 | if (dbs_tuners_ins.ignore_nice) { | |
616 | j_dbs_info->prev_cpu_nice = | |
617 | kstat_cpu(j).cpustat.nice; | |
618 | } | |
b9170836 | 619 | } |
a159b827 AC |
620 | this_dbs_info->down_skip = 0; |
621 | this_dbs_info->requested_freq = policy->cur; | |
914f7c31 | 622 | |
ee88415c | 623 | mutex_init(&this_dbs_info->timer_mutex); |
b9170836 DJ |
624 | dbs_enable++; |
625 | /* | |
626 | * Start the timerschedule work, when this governor | |
627 | * is used for first time | |
628 | */ | |
629 | if (dbs_enable == 1) { | |
630 | unsigned int latency; | |
631 | /* policy latency is in nS. Convert it to uS first */ | |
2c906b31 AC |
632 | latency = policy->cpuinfo.transition_latency / 1000; |
633 | if (latency == 0) | |
634 | latency = 1; | |
b9170836 | 635 | |
49b015ce TR |
636 | rc = sysfs_create_group(cpufreq_global_kobject, |
637 | &dbs_attr_group); | |
638 | if (rc) { | |
639 | mutex_unlock(&dbs_mutex); | |
640 | return rc; | |
641 | } | |
642 | ||
cef9615a TR |
643 | /* |
644 | * conservative does not implement micro like ondemand | |
645 | * governor, thus we are bound to jiffes/HZ | |
646 | */ | |
647 | min_sampling_rate = | |
648 | MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); | |
649 | /* Bring kernel and HW constraints together */ | |
650 | min_sampling_rate = max(min_sampling_rate, | |
651 | MIN_LATENCY_MULTIPLIER * latency); | |
652 | dbs_tuners_ins.sampling_rate = | |
653 | max(min_sampling_rate, | |
654 | latency * LATENCY_MULTIPLIER); | |
b9170836 | 655 | |
a8d7c3bc EO |
656 | cpufreq_register_notifier( |
657 | &dbs_cpufreq_notifier_block, | |
658 | CPUFREQ_TRANSITION_NOTIFIER); | |
b9170836 | 659 | } |
3fc54d37 | 660 | mutex_unlock(&dbs_mutex); |
8e677ce8 | 661 | |
7d26e2d5 | 662 | dbs_timer_init(this_dbs_info); |
663 | ||
b9170836 DJ |
664 | break; |
665 | ||
666 | case CPUFREQ_GOV_STOP: | |
8e677ce8 | 667 | dbs_timer_exit(this_dbs_info); |
7d26e2d5 | 668 | |
669 | mutex_lock(&dbs_mutex); | |
49b015ce | 670 | sysfs_remove_group(&policy->kobj, &dbs_attr_group_old); |
b9170836 | 671 | dbs_enable--; |
ee88415c | 672 | mutex_destroy(&this_dbs_info->timer_mutex); |
8e677ce8 | 673 | |
b9170836 DJ |
674 | /* |
675 | * Stop the timerschedule work, when this governor | |
676 | * is used for first time | |
677 | */ | |
8e677ce8 | 678 | if (dbs_enable == 0) |
a8d7c3bc EO |
679 | cpufreq_unregister_notifier( |
680 | &dbs_cpufreq_notifier_block, | |
681 | CPUFREQ_TRANSITION_NOTIFIER); | |
a8d7c3bc | 682 | |
3fc54d37 | 683 | mutex_unlock(&dbs_mutex); |
49b015ce TR |
684 | if (!dbs_enable) |
685 | sysfs_remove_group(cpufreq_global_kobject, | |
686 | &dbs_attr_group); | |
b9170836 DJ |
687 | |
688 | break; | |
689 | ||
690 | case CPUFREQ_GOV_LIMITS: | |
ee88415c | 691 | mutex_lock(&this_dbs_info->timer_mutex); |
b9170836 DJ |
692 | if (policy->max < this_dbs_info->cur_policy->cur) |
693 | __cpufreq_driver_target( | |
694 | this_dbs_info->cur_policy, | |
18a7247d | 695 | policy->max, CPUFREQ_RELATION_H); |
b9170836 DJ |
696 | else if (policy->min > this_dbs_info->cur_policy->cur) |
697 | __cpufreq_driver_target( | |
698 | this_dbs_info->cur_policy, | |
18a7247d | 699 | policy->min, CPUFREQ_RELATION_L); |
ee88415c | 700 | mutex_unlock(&this_dbs_info->timer_mutex); |
8e677ce8 | 701 | |
b9170836 DJ |
702 | break; |
703 | } | |
704 | return 0; | |
705 | } | |
706 | ||
c4d14bc0 SW |
707 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
708 | static | |
709 | #endif | |
1c256245 TR |
710 | struct cpufreq_governor cpufreq_gov_conservative = { |
711 | .name = "conservative", | |
712 | .governor = cpufreq_governor_dbs, | |
713 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, | |
714 | .owner = THIS_MODULE, | |
b9170836 DJ |
715 | }; |
716 | ||
717 | static int __init cpufreq_gov_dbs_init(void) | |
718 | { | |
8e677ce8 AC |
719 | int err; |
720 | ||
721 | kconservative_wq = create_workqueue("kconservative"); | |
722 | if (!kconservative_wq) { | |
723 | printk(KERN_ERR "Creation of kconservative failed\n"); | |
724 | return -EFAULT; | |
725 | } | |
726 | ||
727 | err = cpufreq_register_governor(&cpufreq_gov_conservative); | |
728 | if (err) | |
729 | destroy_workqueue(kconservative_wq); | |
730 | ||
731 | return err; | |
b9170836 DJ |
732 | } |
733 | ||
734 | static void __exit cpufreq_gov_dbs_exit(void) | |
735 | { | |
1c256245 | 736 | cpufreq_unregister_governor(&cpufreq_gov_conservative); |
8e677ce8 | 737 | destroy_workqueue(kconservative_wq); |
b9170836 DJ |
738 | } |
739 | ||
740 | ||
11a80a9c | 741 | MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>"); |
9acef487 | 742 | MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for " |
b9170836 DJ |
743 | "Low Latency Frequency Transition capable processors " |
744 | "optimised for use in a battery environment"); | |
9acef487 | 745 | MODULE_LICENSE("GPL"); |
b9170836 | 746 | |
6915719b JW |
747 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE |
748 | fs_initcall(cpufreq_gov_dbs_init); | |
749 | #else | |
b9170836 | 750 | module_init(cpufreq_gov_dbs_init); |
6915719b | 751 | #endif |
b9170836 | 752 | module_exit(cpufreq_gov_dbs_exit); |