Commit | Line | Data |
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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> | |
1da177e4 | 15 | #include <linux/init.h> |
1da177e4 | 16 | #include <linux/cpufreq.h> |
138a0128 | 17 | #include <linux/cpu.h> |
1da177e4 LT |
18 | #include <linux/jiffies.h> |
19 | #include <linux/kernel_stat.h> | |
3fc54d37 | 20 | #include <linux/mutex.h> |
80800913 | 21 | #include <linux/hrtimer.h> |
22 | #include <linux/tick.h> | |
23 | #include <linux/ktime.h> | |
9411b4ef | 24 | #include <linux/sched.h> |
1da177e4 LT |
25 | |
26 | /* | |
27 | * dbs is used in this file as a shortform for demandbased switching | |
28 | * It helps to keep variable names smaller, simpler | |
29 | */ | |
30 | ||
e9d95bf7 | 31 | #define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10) |
1da177e4 | 32 | #define DEF_FREQUENCY_UP_THRESHOLD (80) |
80800913 | 33 | #define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3) |
34 | #define MICRO_FREQUENCY_UP_THRESHOLD (95) | |
cef9615a | 35 | #define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000) |
c29f1403 | 36 | #define MIN_FREQUENCY_UP_THRESHOLD (11) |
1da177e4 LT |
37 | #define MAX_FREQUENCY_UP_THRESHOLD (100) |
38 | ||
32ee8c3e DJ |
39 | /* |
40 | * The polling frequency of this governor depends on the capability of | |
1da177e4 | 41 | * the processor. Default polling frequency is 1000 times the transition |
32ee8c3e DJ |
42 | * latency of the processor. The governor will work on any processor with |
43 | * transition latency <= 10mS, using appropriate sampling | |
1da177e4 LT |
44 | * rate. |
45 | * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) | |
46 | * this governor will not work. | |
47 | * All times here are in uS. | |
48 | */ | |
df8b59be | 49 | #define MIN_SAMPLING_RATE_RATIO (2) |
112124ab | 50 | |
cef9615a TR |
51 | static unsigned int min_sampling_rate; |
52 | ||
112124ab | 53 | #define LATENCY_MULTIPLIER (1000) |
cef9615a | 54 | #define MIN_LATENCY_MULTIPLIER (100) |
1c256245 | 55 | #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) |
1da177e4 | 56 | |
c4028958 | 57 | static void do_dbs_timer(struct work_struct *work); |
0e625ac1 TR |
58 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, |
59 | unsigned int event); | |
60 | ||
61 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND | |
62 | static | |
63 | #endif | |
64 | struct cpufreq_governor cpufreq_gov_ondemand = { | |
65 | .name = "ondemand", | |
66 | .governor = cpufreq_governor_dbs, | |
67 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, | |
68 | .owner = THIS_MODULE, | |
69 | }; | |
c4028958 DH |
70 | |
71 | /* Sampling types */ | |
529af7a1 | 72 | enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; |
1da177e4 LT |
73 | |
74 | struct cpu_dbs_info_s { | |
ccb2fe20 VP |
75 | cputime64_t prev_cpu_idle; |
76 | cputime64_t prev_cpu_wall; | |
80800913 | 77 | cputime64_t prev_cpu_nice; |
32ee8c3e | 78 | struct cpufreq_policy *cur_policy; |
2b03f891 | 79 | struct delayed_work work; |
05ca0350 AS |
80 | struct cpufreq_frequency_table *freq_table; |
81 | unsigned int freq_lo; | |
82 | unsigned int freq_lo_jiffies; | |
83 | unsigned int freq_hi_jiffies; | |
529af7a1 | 84 | int cpu; |
5a75c828 | 85 | unsigned int sample_type:1; |
86 | /* | |
87 | * percpu mutex that serializes governor limit change with | |
88 | * do_dbs_timer invocation. We do not want do_dbs_timer to run | |
89 | * when user is changing the governor or limits. | |
90 | */ | |
91 | struct mutex timer_mutex; | |
1da177e4 | 92 | }; |
245b2e70 | 93 | static DEFINE_PER_CPU(struct cpu_dbs_info_s, od_cpu_dbs_info); |
1da177e4 LT |
94 | |
95 | static unsigned int dbs_enable; /* number of CPUs using this policy */ | |
96 | ||
4ec223d0 | 97 | /* |
7d26e2d5 | 98 | * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on |
5a75c828 | 99 | * different CPUs. It protects dbs_enable in governor start/stop. |
4ec223d0 | 100 | */ |
ffac80e9 | 101 | static DEFINE_MUTEX(dbs_mutex); |
1da177e4 | 102 | |
2f8a835c | 103 | static struct workqueue_struct *kondemand_wq; |
6810b548 | 104 | |
05ca0350 | 105 | static struct dbs_tuners { |
32ee8c3e | 106 | unsigned int sampling_rate; |
32ee8c3e | 107 | unsigned int up_threshold; |
e9d95bf7 | 108 | unsigned int down_differential; |
32ee8c3e | 109 | unsigned int ignore_nice; |
05ca0350 AS |
110 | unsigned int powersave_bias; |
111 | } dbs_tuners_ins = { | |
32ee8c3e | 112 | .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
e9d95bf7 | 113 | .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, |
9cbad61b | 114 | .ignore_nice = 0, |
05ca0350 | 115 | .powersave_bias = 0, |
1da177e4 LT |
116 | }; |
117 | ||
80800913 | 118 | static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu, |
119 | cputime64_t *wall) | |
dac1c1a5 | 120 | { |
ea487615 | 121 | cputime64_t idle_time; |
3430502d | 122 | cputime64_t cur_wall_time; |
ea487615 | 123 | cputime64_t busy_time; |
ccb2fe20 | 124 | |
3430502d | 125 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); |
ea487615 VP |
126 | busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user, |
127 | kstat_cpu(cpu).cpustat.system); | |
ccb2fe20 | 128 | |
ea487615 VP |
129 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq); |
130 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq); | |
131 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal); | |
1ca3abdb | 132 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice); |
ea487615 | 133 | |
3430502d | 134 | idle_time = cputime64_sub(cur_wall_time, busy_time); |
135 | if (wall) | |
136 | *wall = cur_wall_time; | |
137 | ||
ea487615 | 138 | return idle_time; |
dac1c1a5 DJ |
139 | } |
140 | ||
80800913 | 141 | static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) |
142 | { | |
143 | u64 idle_time = get_cpu_idle_time_us(cpu, wall); | |
144 | ||
145 | if (idle_time == -1ULL) | |
146 | return get_cpu_idle_time_jiffy(cpu, wall); | |
147 | ||
80800913 | 148 | return idle_time; |
149 | } | |
150 | ||
05ca0350 AS |
151 | /* |
152 | * Find right freq to be set now with powersave_bias on. | |
153 | * Returns the freq_hi to be used right now and will set freq_hi_jiffies, | |
154 | * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs. | |
155 | */ | |
b5ecf60f AB |
156 | static unsigned int powersave_bias_target(struct cpufreq_policy *policy, |
157 | unsigned int freq_next, | |
158 | unsigned int relation) | |
05ca0350 AS |
159 | { |
160 | unsigned int freq_req, freq_reduc, freq_avg; | |
161 | unsigned int freq_hi, freq_lo; | |
162 | unsigned int index = 0; | |
163 | unsigned int jiffies_total, jiffies_hi, jiffies_lo; | |
245b2e70 TH |
164 | struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, |
165 | policy->cpu); | |
05ca0350 AS |
166 | |
167 | if (!dbs_info->freq_table) { | |
168 | dbs_info->freq_lo = 0; | |
169 | dbs_info->freq_lo_jiffies = 0; | |
170 | return freq_next; | |
171 | } | |
172 | ||
173 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next, | |
174 | relation, &index); | |
175 | freq_req = dbs_info->freq_table[index].frequency; | |
176 | freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000; | |
177 | freq_avg = freq_req - freq_reduc; | |
178 | ||
179 | /* Find freq bounds for freq_avg in freq_table */ | |
180 | index = 0; | |
181 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, | |
182 | CPUFREQ_RELATION_H, &index); | |
183 | freq_lo = dbs_info->freq_table[index].frequency; | |
184 | index = 0; | |
185 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, | |
186 | CPUFREQ_RELATION_L, &index); | |
187 | freq_hi = dbs_info->freq_table[index].frequency; | |
188 | ||
189 | /* Find out how long we have to be in hi and lo freqs */ | |
190 | if (freq_hi == freq_lo) { | |
191 | dbs_info->freq_lo = 0; | |
192 | dbs_info->freq_lo_jiffies = 0; | |
193 | return freq_lo; | |
194 | } | |
195 | jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
196 | jiffies_hi = (freq_avg - freq_lo) * jiffies_total; | |
197 | jiffies_hi += ((freq_hi - freq_lo) / 2); | |
198 | jiffies_hi /= (freq_hi - freq_lo); | |
199 | jiffies_lo = jiffies_total - jiffies_hi; | |
200 | dbs_info->freq_lo = freq_lo; | |
201 | dbs_info->freq_lo_jiffies = jiffies_lo; | |
202 | dbs_info->freq_hi_jiffies = jiffies_hi; | |
203 | return freq_hi; | |
204 | } | |
205 | ||
5a75c828 | 206 | static void ondemand_powersave_bias_init_cpu(int cpu) |
207 | { | |
384be2b1 | 208 | struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
5a75c828 | 209 | dbs_info->freq_table = cpufreq_frequency_get_table(cpu); |
210 | dbs_info->freq_lo = 0; | |
211 | } | |
212 | ||
05ca0350 AS |
213 | static void ondemand_powersave_bias_init(void) |
214 | { | |
215 | int i; | |
216 | for_each_online_cpu(i) { | |
5a75c828 | 217 | ondemand_powersave_bias_init_cpu(i); |
05ca0350 AS |
218 | } |
219 | } | |
220 | ||
1da177e4 | 221 | /************************** sysfs interface ************************/ |
0e625ac1 TR |
222 | |
223 | static ssize_t show_sampling_rate_max(struct kobject *kobj, | |
224 | struct attribute *attr, char *buf) | |
1da177e4 | 225 | { |
4f4d1ad6 TR |
226 | printk_once(KERN_INFO "CPUFREQ: ondemand sampling_rate_max " |
227 | "sysfs file is deprecated - used by: %s\n", current->comm); | |
cef9615a | 228 | return sprintf(buf, "%u\n", -1U); |
1da177e4 LT |
229 | } |
230 | ||
0e625ac1 TR |
231 | static ssize_t show_sampling_rate_min(struct kobject *kobj, |
232 | struct attribute *attr, char *buf) | |
1da177e4 | 233 | { |
cef9615a | 234 | return sprintf(buf, "%u\n", min_sampling_rate); |
1da177e4 LT |
235 | } |
236 | ||
32ee8c3e | 237 | #define define_one_ro(_name) \ |
0e625ac1 | 238 | static struct global_attr _name = \ |
1da177e4 LT |
239 | __ATTR(_name, 0444, show_##_name, NULL) |
240 | ||
241 | define_one_ro(sampling_rate_max); | |
242 | define_one_ro(sampling_rate_min); | |
243 | ||
244 | /* cpufreq_ondemand Governor Tunables */ | |
245 | #define show_one(file_name, object) \ | |
246 | static ssize_t show_##file_name \ | |
0e625ac1 | 247 | (struct kobject *kobj, struct attribute *attr, char *buf) \ |
1da177e4 LT |
248 | { \ |
249 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ | |
250 | } | |
251 | show_one(sampling_rate, sampling_rate); | |
1da177e4 | 252 | show_one(up_threshold, up_threshold); |
001893cd | 253 | show_one(ignore_nice_load, ignore_nice); |
05ca0350 | 254 | show_one(powersave_bias, powersave_bias); |
1da177e4 | 255 | |
0e625ac1 TR |
256 | /*** delete after deprecation time ***/ |
257 | ||
258 | #define DEPRECATION_MSG(file_name) \ | |
259 | printk_once(KERN_INFO "CPUFREQ: Per core ondemand sysfs " \ | |
260 | "interface is deprecated - " #file_name "\n"); | |
261 | ||
262 | #define show_one_old(file_name) \ | |
263 | static ssize_t show_##file_name##_old \ | |
264 | (struct cpufreq_policy *unused, char *buf) \ | |
265 | { \ | |
266 | printk_once(KERN_INFO "CPUFREQ: Per core ondemand sysfs " \ | |
267 | "interface is deprecated - " #file_name "\n"); \ | |
268 | return show_##file_name(NULL, NULL, buf); \ | |
269 | } | |
270 | show_one_old(sampling_rate); | |
271 | show_one_old(up_threshold); | |
272 | show_one_old(ignore_nice_load); | |
273 | show_one_old(powersave_bias); | |
274 | show_one_old(sampling_rate_min); | |
275 | show_one_old(sampling_rate_max); | |
276 | ||
277 | #define define_one_ro_old(object, _name) \ | |
278 | static struct freq_attr object = \ | |
279 | __ATTR(_name, 0444, show_##_name##_old, NULL) | |
280 | ||
281 | define_one_ro_old(sampling_rate_min_old, sampling_rate_min); | |
282 | define_one_ro_old(sampling_rate_max_old, sampling_rate_max); | |
283 | ||
284 | /*** delete after deprecation time ***/ | |
285 | ||
286 | static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b, | |
287 | const char *buf, size_t count) | |
1da177e4 LT |
288 | { |
289 | unsigned int input; | |
290 | int ret; | |
ffac80e9 | 291 | ret = sscanf(buf, "%u", &input); |
5a75c828 | 292 | if (ret != 1) |
293 | return -EINVAL; | |
1da177e4 | 294 | |
3fc54d37 | 295 | mutex_lock(&dbs_mutex); |
cef9615a | 296 | dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate); |
3fc54d37 | 297 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
298 | |
299 | return count; | |
300 | } | |
301 | ||
0e625ac1 TR |
302 | static ssize_t store_up_threshold(struct kobject *a, struct attribute *b, |
303 | const char *buf, size_t count) | |
1da177e4 LT |
304 | { |
305 | unsigned int input; | |
306 | int ret; | |
ffac80e9 | 307 | ret = sscanf(buf, "%u", &input); |
1da177e4 | 308 | |
32ee8c3e | 309 | if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || |
c29f1403 | 310 | input < MIN_FREQUENCY_UP_THRESHOLD) { |
1da177e4 LT |
311 | return -EINVAL; |
312 | } | |
313 | ||
5a75c828 | 314 | mutex_lock(&dbs_mutex); |
1da177e4 | 315 | dbs_tuners_ins.up_threshold = input; |
3fc54d37 | 316 | mutex_unlock(&dbs_mutex); |
1da177e4 LT |
317 | |
318 | return count; | |
319 | } | |
320 | ||
0e625ac1 TR |
321 | static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b, |
322 | const char *buf, size_t count) | |
3d5ee9e5 DJ |
323 | { |
324 | unsigned int input; | |
325 | int ret; | |
326 | ||
327 | unsigned int j; | |
32ee8c3e | 328 | |
ffac80e9 | 329 | ret = sscanf(buf, "%u", &input); |
2b03f891 | 330 | if (ret != 1) |
3d5ee9e5 DJ |
331 | return -EINVAL; |
332 | ||
2b03f891 | 333 | if (input > 1) |
3d5ee9e5 | 334 | input = 1; |
32ee8c3e | 335 | |
3fc54d37 | 336 | mutex_lock(&dbs_mutex); |
2b03f891 | 337 | if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ |
3fc54d37 | 338 | mutex_unlock(&dbs_mutex); |
3d5ee9e5 DJ |
339 | return count; |
340 | } | |
341 | dbs_tuners_ins.ignore_nice = input; | |
342 | ||
ccb2fe20 | 343 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 344 | for_each_online_cpu(j) { |
ccb2fe20 | 345 | struct cpu_dbs_info_s *dbs_info; |
245b2e70 | 346 | dbs_info = &per_cpu(od_cpu_dbs_info, j); |
3430502d | 347 | dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
348 | &dbs_info->prev_cpu_wall); | |
1ca3abdb VP |
349 | if (dbs_tuners_ins.ignore_nice) |
350 | dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
351 | ||
3d5ee9e5 | 352 | } |
3fc54d37 | 353 | mutex_unlock(&dbs_mutex); |
3d5ee9e5 DJ |
354 | |
355 | return count; | |
356 | } | |
357 | ||
0e625ac1 TR |
358 | static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b, |
359 | const char *buf, size_t count) | |
05ca0350 AS |
360 | { |
361 | unsigned int input; | |
362 | int ret; | |
363 | ret = sscanf(buf, "%u", &input); | |
364 | ||
365 | if (ret != 1) | |
366 | return -EINVAL; | |
367 | ||
368 | if (input > 1000) | |
369 | input = 1000; | |
370 | ||
371 | mutex_lock(&dbs_mutex); | |
372 | dbs_tuners_ins.powersave_bias = input; | |
373 | ondemand_powersave_bias_init(); | |
374 | mutex_unlock(&dbs_mutex); | |
375 | ||
376 | return count; | |
377 | } | |
378 | ||
1da177e4 | 379 | #define define_one_rw(_name) \ |
0e625ac1 | 380 | static struct global_attr _name = \ |
1da177e4 LT |
381 | __ATTR(_name, 0644, show_##_name, store_##_name) |
382 | ||
383 | define_one_rw(sampling_rate); | |
1da177e4 | 384 | define_one_rw(up_threshold); |
001893cd | 385 | define_one_rw(ignore_nice_load); |
05ca0350 | 386 | define_one_rw(powersave_bias); |
1da177e4 | 387 | |
2b03f891 | 388 | static struct attribute *dbs_attributes[] = { |
1da177e4 LT |
389 | &sampling_rate_max.attr, |
390 | &sampling_rate_min.attr, | |
391 | &sampling_rate.attr, | |
1da177e4 | 392 | &up_threshold.attr, |
001893cd | 393 | &ignore_nice_load.attr, |
05ca0350 | 394 | &powersave_bias.attr, |
1da177e4 LT |
395 | NULL |
396 | }; | |
397 | ||
398 | static struct attribute_group dbs_attr_group = { | |
399 | .attrs = dbs_attributes, | |
400 | .name = "ondemand", | |
401 | }; | |
402 | ||
0e625ac1 TR |
403 | /*** delete after deprecation time ***/ |
404 | ||
405 | #define write_one_old(file_name) \ | |
406 | static ssize_t store_##file_name##_old \ | |
407 | (struct cpufreq_policy *unused, const char *buf, size_t count) \ | |
408 | { \ | |
409 | printk_once(KERN_INFO "CPUFREQ: Per core ondemand sysfs " \ | |
410 | "interface is deprecated - " #file_name "\n"); \ | |
411 | return store_##file_name(NULL, NULL, buf, count); \ | |
412 | } | |
413 | write_one_old(sampling_rate); | |
414 | write_one_old(up_threshold); | |
415 | write_one_old(ignore_nice_load); | |
416 | write_one_old(powersave_bias); | |
417 | ||
418 | #define define_one_rw_old(object, _name) \ | |
419 | static struct freq_attr object = \ | |
420 | __ATTR(_name, 0644, show_##_name##_old, store_##_name##_old) | |
421 | ||
422 | define_one_rw_old(sampling_rate_old, sampling_rate); | |
423 | define_one_rw_old(up_threshold_old, up_threshold); | |
424 | define_one_rw_old(ignore_nice_load_old, ignore_nice_load); | |
425 | define_one_rw_old(powersave_bias_old, powersave_bias); | |
426 | ||
427 | static struct attribute *dbs_attributes_old[] = { | |
428 | &sampling_rate_max_old.attr, | |
429 | &sampling_rate_min_old.attr, | |
430 | &sampling_rate_old.attr, | |
431 | &up_threshold_old.attr, | |
432 | &ignore_nice_load_old.attr, | |
433 | &powersave_bias_old.attr, | |
434 | NULL | |
435 | }; | |
436 | ||
437 | static struct attribute_group dbs_attr_group_old = { | |
438 | .attrs = dbs_attributes_old, | |
439 | .name = "ondemand", | |
440 | }; | |
441 | ||
442 | /*** delete after deprecation time ***/ | |
443 | ||
1da177e4 LT |
444 | /************************** sysfs end ************************/ |
445 | ||
2f8a835c | 446 | static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) |
1da177e4 | 447 | { |
c43aa3bd | 448 | unsigned int max_load_freq; |
1da177e4 LT |
449 | |
450 | struct cpufreq_policy *policy; | |
451 | unsigned int j; | |
452 | ||
05ca0350 | 453 | this_dbs_info->freq_lo = 0; |
1da177e4 | 454 | policy = this_dbs_info->cur_policy; |
ea487615 | 455 | |
32ee8c3e | 456 | /* |
c29f1403 DJ |
457 | * Every sampling_rate, we check, if current idle time is less |
458 | * than 20% (default), then we try to increase frequency | |
ccb2fe20 | 459 | * Every sampling_rate, we look for a the lowest |
c29f1403 DJ |
460 | * frequency which can sustain the load while keeping idle time over |
461 | * 30%. If such a frequency exist, we try to decrease to this frequency. | |
1da177e4 | 462 | * |
32ee8c3e DJ |
463 | * Any frequency increase takes it to the maximum frequency. |
464 | * Frequency reduction happens at minimum steps of | |
465 | * 5% (default) of current frequency | |
1da177e4 LT |
466 | */ |
467 | ||
c43aa3bd | 468 | /* Get Absolute Load - in terms of freq */ |
469 | max_load_freq = 0; | |
470 | ||
835481d9 | 471 | for_each_cpu(j, policy->cpus) { |
1da177e4 | 472 | struct cpu_dbs_info_s *j_dbs_info; |
c43aa3bd | 473 | cputime64_t cur_wall_time, cur_idle_time; |
474 | unsigned int idle_time, wall_time; | |
475 | unsigned int load, load_freq; | |
476 | int freq_avg; | |
1da177e4 | 477 | |
245b2e70 | 478 | j_dbs_info = &per_cpu(od_cpu_dbs_info, j); |
3430502d | 479 | |
480 | cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); | |
481 | ||
c43aa3bd | 482 | wall_time = (unsigned int) cputime64_sub(cur_wall_time, |
483 | j_dbs_info->prev_cpu_wall); | |
484 | j_dbs_info->prev_cpu_wall = cur_wall_time; | |
485 | ||
c43aa3bd | 486 | idle_time = (unsigned int) cputime64_sub(cur_idle_time, |
ccb2fe20 | 487 | j_dbs_info->prev_cpu_idle); |
c43aa3bd | 488 | j_dbs_info->prev_cpu_idle = cur_idle_time; |
1da177e4 | 489 | |
1ca3abdb VP |
490 | if (dbs_tuners_ins.ignore_nice) { |
491 | cputime64_t cur_nice; | |
492 | unsigned long cur_nice_jiffies; | |
493 | ||
494 | cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice, | |
495 | j_dbs_info->prev_cpu_nice); | |
496 | /* | |
497 | * Assumption: nice time between sampling periods will | |
498 | * be less than 2^32 jiffies for 32 bit sys | |
499 | */ | |
500 | cur_nice_jiffies = (unsigned long) | |
501 | cputime64_to_jiffies64(cur_nice); | |
502 | ||
503 | j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
504 | idle_time += jiffies_to_usecs(cur_nice_jiffies); | |
505 | } | |
506 | ||
3430502d | 507 | if (unlikely(!wall_time || wall_time < idle_time)) |
c43aa3bd | 508 | continue; |
c43aa3bd | 509 | |
510 | load = 100 * (wall_time - idle_time) / wall_time; | |
511 | ||
512 | freq_avg = __cpufreq_driver_getavg(policy, j); | |
513 | if (freq_avg <= 0) | |
514 | freq_avg = policy->cur; | |
515 | ||
516 | load_freq = load * freq_avg; | |
517 | if (load_freq > max_load_freq) | |
518 | max_load_freq = load_freq; | |
1da177e4 LT |
519 | } |
520 | ||
ccb2fe20 | 521 | /* Check for frequency increase */ |
c43aa3bd | 522 | if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) { |
c11420a6 | 523 | /* if we are already at full speed then break out early */ |
05ca0350 AS |
524 | if (!dbs_tuners_ins.powersave_bias) { |
525 | if (policy->cur == policy->max) | |
526 | return; | |
527 | ||
528 | __cpufreq_driver_target(policy, policy->max, | |
529 | CPUFREQ_RELATION_H); | |
530 | } else { | |
531 | int freq = powersave_bias_target(policy, policy->max, | |
532 | CPUFREQ_RELATION_H); | |
533 | __cpufreq_driver_target(policy, freq, | |
534 | CPUFREQ_RELATION_L); | |
535 | } | |
1da177e4 LT |
536 | return; |
537 | } | |
538 | ||
539 | /* Check for frequency decrease */ | |
c29f1403 DJ |
540 | /* if we cannot reduce the frequency anymore, break out early */ |
541 | if (policy->cur == policy->min) | |
542 | return; | |
1da177e4 | 543 | |
c29f1403 DJ |
544 | /* |
545 | * The optimal frequency is the frequency that is the lowest that | |
546 | * can support the current CPU usage without triggering the up | |
547 | * policy. To be safe, we focus 10 points under the threshold. | |
548 | */ | |
e9d95bf7 | 549 | if (max_load_freq < |
550 | (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) * | |
551 | policy->cur) { | |
c43aa3bd | 552 | unsigned int freq_next; |
e9d95bf7 | 553 | freq_next = max_load_freq / |
554 | (dbs_tuners_ins.up_threshold - | |
555 | dbs_tuners_ins.down_differential); | |
dfde5d62 | 556 | |
05ca0350 AS |
557 | if (!dbs_tuners_ins.powersave_bias) { |
558 | __cpufreq_driver_target(policy, freq_next, | |
559 | CPUFREQ_RELATION_L); | |
560 | } else { | |
561 | int freq = powersave_bias_target(policy, freq_next, | |
562 | CPUFREQ_RELATION_L); | |
563 | __cpufreq_driver_target(policy, freq, | |
564 | CPUFREQ_RELATION_L); | |
565 | } | |
ccb2fe20 | 566 | } |
1da177e4 LT |
567 | } |
568 | ||
c4028958 | 569 | static void do_dbs_timer(struct work_struct *work) |
32ee8c3e | 570 | { |
529af7a1 VP |
571 | struct cpu_dbs_info_s *dbs_info = |
572 | container_of(work, struct cpu_dbs_info_s, work.work); | |
573 | unsigned int cpu = dbs_info->cpu; | |
574 | int sample_type = dbs_info->sample_type; | |
575 | ||
1ce28d6b AS |
576 | /* We want all CPUs to do sampling nearly on same jiffy */ |
577 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
c4028958 | 578 | |
1ce28d6b | 579 | delay -= jiffies % delay; |
5a75c828 | 580 | mutex_lock(&dbs_info->timer_mutex); |
56463b78 | 581 | |
05ca0350 | 582 | /* Common NORMAL_SAMPLE setup */ |
c4028958 | 583 | dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
05ca0350 | 584 | if (!dbs_tuners_ins.powersave_bias || |
c4028958 | 585 | sample_type == DBS_NORMAL_SAMPLE) { |
05ca0350 | 586 | dbs_check_cpu(dbs_info); |
05ca0350 AS |
587 | if (dbs_info->freq_lo) { |
588 | /* Setup timer for SUB_SAMPLE */ | |
c4028958 | 589 | dbs_info->sample_type = DBS_SUB_SAMPLE; |
05ca0350 AS |
590 | delay = dbs_info->freq_hi_jiffies; |
591 | } | |
592 | } else { | |
593 | __cpufreq_driver_target(dbs_info->cur_policy, | |
2b03f891 | 594 | dbs_info->freq_lo, CPUFREQ_RELATION_H); |
05ca0350 | 595 | } |
1ce28d6b | 596 | queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); |
5a75c828 | 597 | mutex_unlock(&dbs_info->timer_mutex); |
32ee8c3e | 598 | } |
1da177e4 | 599 | |
529af7a1 | 600 | static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) |
1da177e4 | 601 | { |
1ce28d6b AS |
602 | /* We want all CPUs to do sampling nearly on same jiffy */ |
603 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
604 | delay -= jiffies % delay; | |
2f8a835c | 605 | |
c4028958 | 606 | dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
28287033 | 607 | INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); |
529af7a1 | 608 | queue_delayed_work_on(dbs_info->cpu, kondemand_wq, &dbs_info->work, |
2b03f891 | 609 | delay); |
1da177e4 LT |
610 | } |
611 | ||
2cd7cbdf | 612 | static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) |
1da177e4 | 613 | { |
b14893a6 | 614 | cancel_delayed_work_sync(&dbs_info->work); |
1da177e4 LT |
615 | } |
616 | ||
617 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, | |
618 | unsigned int event) | |
619 | { | |
620 | unsigned int cpu = policy->cpu; | |
621 | struct cpu_dbs_info_s *this_dbs_info; | |
622 | unsigned int j; | |
914f7c31 | 623 | int rc; |
1da177e4 | 624 | |
245b2e70 | 625 | this_dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
1da177e4 LT |
626 | |
627 | switch (event) { | |
628 | case CPUFREQ_GOV_START: | |
ffac80e9 | 629 | if ((!cpu_online(cpu)) || (!policy->cur)) |
1da177e4 LT |
630 | return -EINVAL; |
631 | ||
3fc54d37 | 632 | mutex_lock(&dbs_mutex); |
914f7c31 | 633 | |
0e625ac1 | 634 | rc = sysfs_create_group(&policy->kobj, &dbs_attr_group_old); |
914f7c31 | 635 | if (rc) { |
914f7c31 JG |
636 | mutex_unlock(&dbs_mutex); |
637 | return rc; | |
638 | } | |
639 | ||
5a75c828 | 640 | dbs_enable++; |
835481d9 | 641 | for_each_cpu(j, policy->cpus) { |
1da177e4 | 642 | struct cpu_dbs_info_s *j_dbs_info; |
245b2e70 | 643 | j_dbs_info = &per_cpu(od_cpu_dbs_info, j); |
1da177e4 | 644 | j_dbs_info->cur_policy = policy; |
32ee8c3e | 645 | |
3430502d | 646 | j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
647 | &j_dbs_info->prev_cpu_wall); | |
1ca3abdb VP |
648 | if (dbs_tuners_ins.ignore_nice) { |
649 | j_dbs_info->prev_cpu_nice = | |
650 | kstat_cpu(j).cpustat.nice; | |
651 | } | |
1da177e4 | 652 | } |
529af7a1 | 653 | this_dbs_info->cpu = cpu; |
5a75c828 | 654 | ondemand_powersave_bias_init_cpu(cpu); |
1da177e4 LT |
655 | /* |
656 | * Start the timerschedule work, when this governor | |
657 | * is used for first time | |
658 | */ | |
659 | if (dbs_enable == 1) { | |
660 | unsigned int latency; | |
0e625ac1 TR |
661 | |
662 | rc = sysfs_create_group(cpufreq_global_kobject, | |
663 | &dbs_attr_group); | |
664 | if (rc) { | |
665 | mutex_unlock(&dbs_mutex); | |
666 | return rc; | |
667 | } | |
668 | ||
1da177e4 | 669 | /* policy latency is in nS. Convert it to uS first */ |
df8b59be DJ |
670 | latency = policy->cpuinfo.transition_latency / 1000; |
671 | if (latency == 0) | |
672 | latency = 1; | |
cef9615a TR |
673 | /* Bring kernel and HW constraints together */ |
674 | min_sampling_rate = max(min_sampling_rate, | |
675 | MIN_LATENCY_MULTIPLIER * latency); | |
676 | dbs_tuners_ins.sampling_rate = | |
677 | max(min_sampling_rate, | |
678 | latency * LATENCY_MULTIPLIER); | |
1da177e4 | 679 | } |
3fc54d37 | 680 | mutex_unlock(&dbs_mutex); |
7d26e2d5 | 681 | |
0e625ac1 | 682 | mutex_init(&this_dbs_info->timer_mutex); |
7d26e2d5 | 683 | dbs_timer_init(this_dbs_info); |
1da177e4 LT |
684 | break; |
685 | ||
686 | case CPUFREQ_GOV_STOP: | |
2cd7cbdf | 687 | dbs_timer_exit(this_dbs_info); |
7d26e2d5 | 688 | |
689 | mutex_lock(&dbs_mutex); | |
0e625ac1 | 690 | sysfs_remove_group(&policy->kobj, &dbs_attr_group_old); |
5a75c828 | 691 | mutex_destroy(&this_dbs_info->timer_mutex); |
1da177e4 | 692 | dbs_enable--; |
3fc54d37 | 693 | mutex_unlock(&dbs_mutex); |
0e625ac1 TR |
694 | if (!dbs_enable) |
695 | sysfs_remove_group(cpufreq_global_kobject, | |
696 | &dbs_attr_group); | |
1da177e4 LT |
697 | |
698 | break; | |
699 | ||
700 | case CPUFREQ_GOV_LIMITS: | |
5a75c828 | 701 | mutex_lock(&this_dbs_info->timer_mutex); |
1da177e4 | 702 | if (policy->max < this_dbs_info->cur_policy->cur) |
ffac80e9 | 703 | __cpufreq_driver_target(this_dbs_info->cur_policy, |
2b03f891 | 704 | policy->max, CPUFREQ_RELATION_H); |
1da177e4 | 705 | else if (policy->min > this_dbs_info->cur_policy->cur) |
ffac80e9 | 706 | __cpufreq_driver_target(this_dbs_info->cur_policy, |
2b03f891 | 707 | policy->min, CPUFREQ_RELATION_L); |
5a75c828 | 708 | mutex_unlock(&this_dbs_info->timer_mutex); |
1da177e4 LT |
709 | break; |
710 | } | |
711 | return 0; | |
712 | } | |
713 | ||
1da177e4 LT |
714 | static int __init cpufreq_gov_dbs_init(void) |
715 | { | |
888a794c | 716 | int err; |
80800913 | 717 | cputime64_t wall; |
4f6e6b9f AR |
718 | u64 idle_time; |
719 | int cpu = get_cpu(); | |
80800913 | 720 | |
4f6e6b9f AR |
721 | idle_time = get_cpu_idle_time_us(cpu, &wall); |
722 | put_cpu(); | |
80800913 | 723 | if (idle_time != -1ULL) { |
724 | /* Idle micro accounting is supported. Use finer thresholds */ | |
725 | dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; | |
726 | dbs_tuners_ins.down_differential = | |
727 | MICRO_FREQUENCY_DOWN_DIFFERENTIAL; | |
cef9615a TR |
728 | /* |
729 | * In no_hz/micro accounting case we set the minimum frequency | |
730 | * not depending on HZ, but fixed (very low). The deferred | |
731 | * timer might skip some samples if idle/sleeping as needed. | |
732 | */ | |
733 | min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE; | |
734 | } else { | |
735 | /* For correct statistics, we need 10 ticks for each measure */ | |
736 | min_sampling_rate = | |
737 | MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); | |
80800913 | 738 | } |
888a794c | 739 | |
56463b78 VP |
740 | kondemand_wq = create_workqueue("kondemand"); |
741 | if (!kondemand_wq) { | |
742 | printk(KERN_ERR "Creation of kondemand failed\n"); | |
743 | return -EFAULT; | |
744 | } | |
888a794c AM |
745 | err = cpufreq_register_governor(&cpufreq_gov_ondemand); |
746 | if (err) | |
747 | destroy_workqueue(kondemand_wq); | |
748 | ||
749 | return err; | |
1da177e4 LT |
750 | } |
751 | ||
752 | static void __exit cpufreq_gov_dbs_exit(void) | |
753 | { | |
1c256245 | 754 | cpufreq_unregister_governor(&cpufreq_gov_ondemand); |
56463b78 | 755 | destroy_workqueue(kondemand_wq); |
1da177e4 LT |
756 | } |
757 | ||
758 | ||
ffac80e9 VP |
759 | MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); |
760 | MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); | |
761 | MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " | |
2b03f891 | 762 | "Low Latency Frequency Transition capable processors"); |
ffac80e9 | 763 | MODULE_LICENSE("GPL"); |
1da177e4 | 764 | |
6915719b JW |
765 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
766 | fs_initcall(cpufreq_gov_dbs_init); | |
767 | #else | |
1da177e4 | 768 | module_init(cpufreq_gov_dbs_init); |
6915719b | 769 | #endif |
1da177e4 | 770 | module_exit(cpufreq_gov_dbs_exit); |