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> | |
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) |
3f78a9f7 DN |
33 | #define DEF_SAMPLING_DOWN_FACTOR (1) |
34 | #define MAX_SAMPLING_DOWN_FACTOR (100000) | |
80800913 | 35 | #define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3) |
36 | #define MICRO_FREQUENCY_UP_THRESHOLD (95) | |
cef9615a | 37 | #define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000) |
c29f1403 | 38 | #define MIN_FREQUENCY_UP_THRESHOLD (11) |
1da177e4 LT |
39 | #define MAX_FREQUENCY_UP_THRESHOLD (100) |
40 | ||
32ee8c3e DJ |
41 | /* |
42 | * The polling frequency of this governor depends on the capability of | |
1da177e4 | 43 | * the processor. Default polling frequency is 1000 times the transition |
32ee8c3e DJ |
44 | * latency of the processor. The governor will work on any processor with |
45 | * transition latency <= 10mS, using appropriate sampling | |
1da177e4 LT |
46 | * rate. |
47 | * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) | |
48 | * this governor will not work. | |
49 | * All times here are in uS. | |
50 | */ | |
df8b59be | 51 | #define MIN_SAMPLING_RATE_RATIO (2) |
112124ab | 52 | |
cef9615a TR |
53 | static unsigned int min_sampling_rate; |
54 | ||
112124ab | 55 | #define LATENCY_MULTIPLIER (1000) |
cef9615a | 56 | #define MIN_LATENCY_MULTIPLIER (100) |
1c256245 | 57 | #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) |
1da177e4 | 58 | |
c4028958 | 59 | static void do_dbs_timer(struct work_struct *work); |
0e625ac1 TR |
60 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, |
61 | unsigned int event); | |
62 | ||
63 | #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND | |
64 | static | |
65 | #endif | |
66 | struct cpufreq_governor cpufreq_gov_ondemand = { | |
67 | .name = "ondemand", | |
68 | .governor = cpufreq_governor_dbs, | |
69 | .max_transition_latency = TRANSITION_LATENCY_LIMIT, | |
70 | .owner = THIS_MODULE, | |
71 | }; | |
c4028958 DH |
72 | |
73 | /* Sampling types */ | |
529af7a1 | 74 | enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; |
1da177e4 LT |
75 | |
76 | struct cpu_dbs_info_s { | |
ccb2fe20 | 77 | cputime64_t prev_cpu_idle; |
6b8fcd90 | 78 | cputime64_t prev_cpu_iowait; |
ccb2fe20 | 79 | cputime64_t prev_cpu_wall; |
80800913 | 80 | cputime64_t prev_cpu_nice; |
32ee8c3e | 81 | struct cpufreq_policy *cur_policy; |
2b03f891 | 82 | struct delayed_work work; |
05ca0350 AS |
83 | struct cpufreq_frequency_table *freq_table; |
84 | unsigned int freq_lo; | |
85 | unsigned int freq_lo_jiffies; | |
86 | unsigned int freq_hi_jiffies; | |
3f78a9f7 | 87 | unsigned int rate_mult; |
529af7a1 | 88 | int cpu; |
5a75c828 | 89 | unsigned int sample_type:1; |
90 | /* | |
91 | * percpu mutex that serializes governor limit change with | |
92 | * do_dbs_timer invocation. We do not want do_dbs_timer to run | |
93 | * when user is changing the governor or limits. | |
94 | */ | |
95 | struct mutex timer_mutex; | |
1da177e4 | 96 | }; |
245b2e70 | 97 | static DEFINE_PER_CPU(struct cpu_dbs_info_s, od_cpu_dbs_info); |
1da177e4 LT |
98 | |
99 | static unsigned int dbs_enable; /* number of CPUs using this policy */ | |
100 | ||
4ec223d0 | 101 | /* |
326c86de | 102 | * dbs_mutex protects dbs_enable in governor start/stop. |
4ec223d0 | 103 | */ |
ffac80e9 | 104 | static DEFINE_MUTEX(dbs_mutex); |
1da177e4 | 105 | |
05ca0350 | 106 | static struct dbs_tuners { |
32ee8c3e | 107 | unsigned int sampling_rate; |
32ee8c3e | 108 | unsigned int up_threshold; |
e9d95bf7 | 109 | unsigned int down_differential; |
32ee8c3e | 110 | unsigned int ignore_nice; |
3f78a9f7 | 111 | unsigned int sampling_down_factor; |
05ca0350 | 112 | unsigned int powersave_bias; |
19379b11 | 113 | unsigned int io_is_busy; |
05ca0350 | 114 | } dbs_tuners_ins = { |
32ee8c3e | 115 | .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
3f78a9f7 | 116 | .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, |
e9d95bf7 | 117 | .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, |
9cbad61b | 118 | .ignore_nice = 0, |
05ca0350 | 119 | .powersave_bias = 0, |
1da177e4 LT |
120 | }; |
121 | ||
80800913 | 122 | static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu, |
123 | cputime64_t *wall) | |
dac1c1a5 | 124 | { |
ea487615 | 125 | cputime64_t idle_time; |
3430502d | 126 | cputime64_t cur_wall_time; |
ea487615 | 127 | cputime64_t busy_time; |
ccb2fe20 | 128 | |
3430502d | 129 | cur_wall_time = jiffies64_to_cputime64(get_jiffies_64()); |
ea487615 VP |
130 | busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user, |
131 | kstat_cpu(cpu).cpustat.system); | |
ccb2fe20 | 132 | |
ea487615 VP |
133 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq); |
134 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq); | |
135 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal); | |
1ca3abdb | 136 | busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice); |
ea487615 | 137 | |
3430502d | 138 | idle_time = cputime64_sub(cur_wall_time, busy_time); |
139 | if (wall) | |
54c9a35d | 140 | *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time); |
3430502d | 141 | |
54c9a35d | 142 | return (cputime64_t)jiffies_to_usecs(idle_time); |
dac1c1a5 DJ |
143 | } |
144 | ||
80800913 | 145 | static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) |
146 | { | |
6beea0cd | 147 | u64 idle_time = get_cpu_idle_time_us(cpu, NULL); |
80800913 | 148 | |
149 | if (idle_time == -1ULL) | |
150 | return get_cpu_idle_time_jiffy(cpu, wall); | |
6beea0cd MH |
151 | else |
152 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
80800913 | 153 | |
80800913 | 154 | return idle_time; |
155 | } | |
156 | ||
6b8fcd90 AV |
157 | static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall) |
158 | { | |
159 | u64 iowait_time = get_cpu_iowait_time_us(cpu, wall); | |
160 | ||
161 | if (iowait_time == -1ULL) | |
162 | return 0; | |
163 | ||
164 | return iowait_time; | |
165 | } | |
166 | ||
05ca0350 AS |
167 | /* |
168 | * Find right freq to be set now with powersave_bias on. | |
169 | * Returns the freq_hi to be used right now and will set freq_hi_jiffies, | |
170 | * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs. | |
171 | */ | |
b5ecf60f AB |
172 | static unsigned int powersave_bias_target(struct cpufreq_policy *policy, |
173 | unsigned int freq_next, | |
174 | unsigned int relation) | |
05ca0350 AS |
175 | { |
176 | unsigned int freq_req, freq_reduc, freq_avg; | |
177 | unsigned int freq_hi, freq_lo; | |
178 | unsigned int index = 0; | |
179 | unsigned int jiffies_total, jiffies_hi, jiffies_lo; | |
245b2e70 TH |
180 | struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, |
181 | policy->cpu); | |
05ca0350 AS |
182 | |
183 | if (!dbs_info->freq_table) { | |
184 | dbs_info->freq_lo = 0; | |
185 | dbs_info->freq_lo_jiffies = 0; | |
186 | return freq_next; | |
187 | } | |
188 | ||
189 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next, | |
190 | relation, &index); | |
191 | freq_req = dbs_info->freq_table[index].frequency; | |
192 | freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000; | |
193 | freq_avg = freq_req - freq_reduc; | |
194 | ||
195 | /* Find freq bounds for freq_avg in freq_table */ | |
196 | index = 0; | |
197 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, | |
198 | CPUFREQ_RELATION_H, &index); | |
199 | freq_lo = dbs_info->freq_table[index].frequency; | |
200 | index = 0; | |
201 | cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, | |
202 | CPUFREQ_RELATION_L, &index); | |
203 | freq_hi = dbs_info->freq_table[index].frequency; | |
204 | ||
205 | /* Find out how long we have to be in hi and lo freqs */ | |
206 | if (freq_hi == freq_lo) { | |
207 | dbs_info->freq_lo = 0; | |
208 | dbs_info->freq_lo_jiffies = 0; | |
209 | return freq_lo; | |
210 | } | |
211 | jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
212 | jiffies_hi = (freq_avg - freq_lo) * jiffies_total; | |
213 | jiffies_hi += ((freq_hi - freq_lo) / 2); | |
214 | jiffies_hi /= (freq_hi - freq_lo); | |
215 | jiffies_lo = jiffies_total - jiffies_hi; | |
216 | dbs_info->freq_lo = freq_lo; | |
217 | dbs_info->freq_lo_jiffies = jiffies_lo; | |
218 | dbs_info->freq_hi_jiffies = jiffies_hi; | |
219 | return freq_hi; | |
220 | } | |
221 | ||
5a75c828 | 222 | static void ondemand_powersave_bias_init_cpu(int cpu) |
223 | { | |
384be2b1 | 224 | struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
5a75c828 | 225 | dbs_info->freq_table = cpufreq_frequency_get_table(cpu); |
226 | dbs_info->freq_lo = 0; | |
227 | } | |
228 | ||
05ca0350 AS |
229 | static void ondemand_powersave_bias_init(void) |
230 | { | |
231 | int i; | |
232 | for_each_online_cpu(i) { | |
5a75c828 | 233 | ondemand_powersave_bias_init_cpu(i); |
05ca0350 AS |
234 | } |
235 | } | |
236 | ||
1da177e4 | 237 | /************************** sysfs interface ************************/ |
0e625ac1 | 238 | |
0e625ac1 TR |
239 | static ssize_t show_sampling_rate_min(struct kobject *kobj, |
240 | struct attribute *attr, char *buf) | |
1da177e4 | 241 | { |
cef9615a | 242 | return sprintf(buf, "%u\n", min_sampling_rate); |
1da177e4 LT |
243 | } |
244 | ||
6dad2a29 | 245 | define_one_global_ro(sampling_rate_min); |
1da177e4 LT |
246 | |
247 | /* cpufreq_ondemand Governor Tunables */ | |
248 | #define show_one(file_name, object) \ | |
249 | static ssize_t show_##file_name \ | |
0e625ac1 | 250 | (struct kobject *kobj, struct attribute *attr, char *buf) \ |
1da177e4 LT |
251 | { \ |
252 | return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ | |
253 | } | |
254 | show_one(sampling_rate, sampling_rate); | |
19379b11 | 255 | show_one(io_is_busy, io_is_busy); |
1da177e4 | 256 | show_one(up_threshold, up_threshold); |
3f78a9f7 | 257 | show_one(sampling_down_factor, sampling_down_factor); |
001893cd | 258 | show_one(ignore_nice_load, ignore_nice); |
05ca0350 | 259 | show_one(powersave_bias, powersave_bias); |
1da177e4 | 260 | |
0e625ac1 TR |
261 | static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b, |
262 | const char *buf, size_t count) | |
1da177e4 LT |
263 | { |
264 | unsigned int input; | |
265 | int ret; | |
ffac80e9 | 266 | ret = sscanf(buf, "%u", &input); |
5a75c828 | 267 | if (ret != 1) |
268 | return -EINVAL; | |
cef9615a | 269 | dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate); |
1da177e4 LT |
270 | return count; |
271 | } | |
272 | ||
19379b11 AV |
273 | static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b, |
274 | const char *buf, size_t count) | |
275 | { | |
276 | unsigned int input; | |
277 | int ret; | |
278 | ||
279 | ret = sscanf(buf, "%u", &input); | |
280 | if (ret != 1) | |
281 | return -EINVAL; | |
19379b11 | 282 | dbs_tuners_ins.io_is_busy = !!input; |
19379b11 AV |
283 | return count; |
284 | } | |
285 | ||
0e625ac1 TR |
286 | static ssize_t store_up_threshold(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); |
1da177e4 | 292 | |
32ee8c3e | 293 | if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || |
c29f1403 | 294 | input < MIN_FREQUENCY_UP_THRESHOLD) { |
1da177e4 LT |
295 | return -EINVAL; |
296 | } | |
1da177e4 | 297 | dbs_tuners_ins.up_threshold = input; |
1da177e4 LT |
298 | return count; |
299 | } | |
300 | ||
3f78a9f7 DN |
301 | static ssize_t store_sampling_down_factor(struct kobject *a, |
302 | struct attribute *b, const char *buf, size_t count) | |
303 | { | |
304 | unsigned int input, j; | |
305 | int ret; | |
306 | ret = sscanf(buf, "%u", &input); | |
307 | ||
308 | if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) | |
309 | return -EINVAL; | |
3f78a9f7 DN |
310 | dbs_tuners_ins.sampling_down_factor = input; |
311 | ||
312 | /* Reset down sampling multiplier in case it was active */ | |
313 | for_each_online_cpu(j) { | |
314 | struct cpu_dbs_info_s *dbs_info; | |
315 | dbs_info = &per_cpu(od_cpu_dbs_info, j); | |
316 | dbs_info->rate_mult = 1; | |
317 | } | |
3f78a9f7 DN |
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 | |
2b03f891 | 336 | if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ |
3d5ee9e5 DJ |
337 | return count; |
338 | } | |
339 | dbs_tuners_ins.ignore_nice = input; | |
340 | ||
ccb2fe20 | 341 | /* we need to re-evaluate prev_cpu_idle */ |
dac1c1a5 | 342 | for_each_online_cpu(j) { |
ccb2fe20 | 343 | struct cpu_dbs_info_s *dbs_info; |
245b2e70 | 344 | dbs_info = &per_cpu(od_cpu_dbs_info, j); |
3430502d | 345 | dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
346 | &dbs_info->prev_cpu_wall); | |
1ca3abdb VP |
347 | if (dbs_tuners_ins.ignore_nice) |
348 | dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
349 | ||
3d5ee9e5 | 350 | } |
3d5ee9e5 DJ |
351 | return count; |
352 | } | |
353 | ||
0e625ac1 TR |
354 | static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b, |
355 | const char *buf, size_t count) | |
05ca0350 AS |
356 | { |
357 | unsigned int input; | |
358 | int ret; | |
359 | ret = sscanf(buf, "%u", &input); | |
360 | ||
361 | if (ret != 1) | |
362 | return -EINVAL; | |
363 | ||
364 | if (input > 1000) | |
365 | input = 1000; | |
366 | ||
05ca0350 AS |
367 | dbs_tuners_ins.powersave_bias = input; |
368 | ondemand_powersave_bias_init(); | |
05ca0350 AS |
369 | return count; |
370 | } | |
371 | ||
6dad2a29 | 372 | define_one_global_rw(sampling_rate); |
07d77759 | 373 | define_one_global_rw(io_is_busy); |
6dad2a29 | 374 | define_one_global_rw(up_threshold); |
3f78a9f7 | 375 | define_one_global_rw(sampling_down_factor); |
6dad2a29 BP |
376 | define_one_global_rw(ignore_nice_load); |
377 | define_one_global_rw(powersave_bias); | |
1da177e4 | 378 | |
2b03f891 | 379 | static struct attribute *dbs_attributes[] = { |
1da177e4 LT |
380 | &sampling_rate_min.attr, |
381 | &sampling_rate.attr, | |
1da177e4 | 382 | &up_threshold.attr, |
3f78a9f7 | 383 | &sampling_down_factor.attr, |
001893cd | 384 | &ignore_nice_load.attr, |
05ca0350 | 385 | &powersave_bias.attr, |
19379b11 | 386 | &io_is_busy.attr, |
1da177e4 LT |
387 | NULL |
388 | }; | |
389 | ||
390 | static struct attribute_group dbs_attr_group = { | |
391 | .attrs = dbs_attributes, | |
392 | .name = "ondemand", | |
393 | }; | |
394 | ||
395 | /************************** sysfs end ************************/ | |
396 | ||
00e299ff MC |
397 | static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq) |
398 | { | |
399 | if (dbs_tuners_ins.powersave_bias) | |
400 | freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H); | |
401 | else if (p->cur == p->max) | |
402 | return; | |
403 | ||
404 | __cpufreq_driver_target(p, freq, dbs_tuners_ins.powersave_bias ? | |
405 | CPUFREQ_RELATION_L : CPUFREQ_RELATION_H); | |
406 | } | |
407 | ||
2f8a835c | 408 | static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) |
1da177e4 | 409 | { |
c43aa3bd | 410 | unsigned int max_load_freq; |
1da177e4 LT |
411 | |
412 | struct cpufreq_policy *policy; | |
413 | unsigned int j; | |
414 | ||
05ca0350 | 415 | this_dbs_info->freq_lo = 0; |
1da177e4 | 416 | policy = this_dbs_info->cur_policy; |
ea487615 | 417 | |
32ee8c3e | 418 | /* |
c29f1403 DJ |
419 | * Every sampling_rate, we check, if current idle time is less |
420 | * than 20% (default), then we try to increase frequency | |
ccb2fe20 | 421 | * Every sampling_rate, we look for a the lowest |
c29f1403 DJ |
422 | * frequency which can sustain the load while keeping idle time over |
423 | * 30%. If such a frequency exist, we try to decrease to this frequency. | |
1da177e4 | 424 | * |
32ee8c3e DJ |
425 | * Any frequency increase takes it to the maximum frequency. |
426 | * Frequency reduction happens at minimum steps of | |
427 | * 5% (default) of current frequency | |
1da177e4 LT |
428 | */ |
429 | ||
c43aa3bd | 430 | /* Get Absolute Load - in terms of freq */ |
431 | max_load_freq = 0; | |
432 | ||
835481d9 | 433 | for_each_cpu(j, policy->cpus) { |
1da177e4 | 434 | struct cpu_dbs_info_s *j_dbs_info; |
6b8fcd90 AV |
435 | cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time; |
436 | unsigned int idle_time, wall_time, iowait_time; | |
c43aa3bd | 437 | unsigned int load, load_freq; |
438 | int freq_avg; | |
1da177e4 | 439 | |
245b2e70 | 440 | j_dbs_info = &per_cpu(od_cpu_dbs_info, j); |
3430502d | 441 | |
442 | cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); | |
6b8fcd90 | 443 | cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time); |
3430502d | 444 | |
c43aa3bd | 445 | wall_time = (unsigned int) cputime64_sub(cur_wall_time, |
446 | j_dbs_info->prev_cpu_wall); | |
447 | j_dbs_info->prev_cpu_wall = cur_wall_time; | |
448 | ||
c43aa3bd | 449 | idle_time = (unsigned int) cputime64_sub(cur_idle_time, |
ccb2fe20 | 450 | j_dbs_info->prev_cpu_idle); |
c43aa3bd | 451 | j_dbs_info->prev_cpu_idle = cur_idle_time; |
1da177e4 | 452 | |
6b8fcd90 AV |
453 | iowait_time = (unsigned int) cputime64_sub(cur_iowait_time, |
454 | j_dbs_info->prev_cpu_iowait); | |
455 | j_dbs_info->prev_cpu_iowait = cur_iowait_time; | |
456 | ||
1ca3abdb VP |
457 | if (dbs_tuners_ins.ignore_nice) { |
458 | cputime64_t cur_nice; | |
459 | unsigned long cur_nice_jiffies; | |
460 | ||
461 | cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice, | |
462 | j_dbs_info->prev_cpu_nice); | |
463 | /* | |
464 | * Assumption: nice time between sampling periods will | |
465 | * be less than 2^32 jiffies for 32 bit sys | |
466 | */ | |
467 | cur_nice_jiffies = (unsigned long) | |
468 | cputime64_to_jiffies64(cur_nice); | |
469 | ||
470 | j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; | |
471 | idle_time += jiffies_to_usecs(cur_nice_jiffies); | |
472 | } | |
473 | ||
6b8fcd90 AV |
474 | /* |
475 | * For the purpose of ondemand, waiting for disk IO is an | |
476 | * indication that you're performance critical, and not that | |
477 | * the system is actually idle. So subtract the iowait time | |
478 | * from the cpu idle time. | |
479 | */ | |
480 | ||
19379b11 | 481 | if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time) |
6b8fcd90 AV |
482 | idle_time -= iowait_time; |
483 | ||
3430502d | 484 | if (unlikely(!wall_time || wall_time < idle_time)) |
c43aa3bd | 485 | continue; |
c43aa3bd | 486 | |
487 | load = 100 * (wall_time - idle_time) / wall_time; | |
488 | ||
489 | freq_avg = __cpufreq_driver_getavg(policy, j); | |
490 | if (freq_avg <= 0) | |
491 | freq_avg = policy->cur; | |
492 | ||
493 | load_freq = load * freq_avg; | |
494 | if (load_freq > max_load_freq) | |
495 | max_load_freq = load_freq; | |
1da177e4 LT |
496 | } |
497 | ||
ccb2fe20 | 498 | /* Check for frequency increase */ |
c43aa3bd | 499 | if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) { |
3f78a9f7 DN |
500 | /* If switching to max speed, apply sampling_down_factor */ |
501 | if (policy->cur < policy->max) | |
502 | this_dbs_info->rate_mult = | |
503 | dbs_tuners_ins.sampling_down_factor; | |
00e299ff | 504 | dbs_freq_increase(policy, policy->max); |
1da177e4 LT |
505 | return; |
506 | } | |
507 | ||
508 | /* Check for frequency decrease */ | |
c29f1403 DJ |
509 | /* if we cannot reduce the frequency anymore, break out early */ |
510 | if (policy->cur == policy->min) | |
511 | return; | |
1da177e4 | 512 | |
c29f1403 DJ |
513 | /* |
514 | * The optimal frequency is the frequency that is the lowest that | |
515 | * can support the current CPU usage without triggering the up | |
516 | * policy. To be safe, we focus 10 points under the threshold. | |
517 | */ | |
e9d95bf7 | 518 | if (max_load_freq < |
519 | (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) * | |
520 | policy->cur) { | |
c43aa3bd | 521 | unsigned int freq_next; |
e9d95bf7 | 522 | freq_next = max_load_freq / |
523 | (dbs_tuners_ins.up_threshold - | |
524 | dbs_tuners_ins.down_differential); | |
dfde5d62 | 525 | |
3f78a9f7 DN |
526 | /* No longer fully busy, reset rate_mult */ |
527 | this_dbs_info->rate_mult = 1; | |
528 | ||
1dbf5888 NC |
529 | if (freq_next < policy->min) |
530 | freq_next = policy->min; | |
531 | ||
05ca0350 AS |
532 | if (!dbs_tuners_ins.powersave_bias) { |
533 | __cpufreq_driver_target(policy, freq_next, | |
534 | CPUFREQ_RELATION_L); | |
535 | } else { | |
536 | int freq = powersave_bias_target(policy, freq_next, | |
537 | CPUFREQ_RELATION_L); | |
538 | __cpufreq_driver_target(policy, freq, | |
539 | CPUFREQ_RELATION_L); | |
540 | } | |
ccb2fe20 | 541 | } |
1da177e4 LT |
542 | } |
543 | ||
c4028958 | 544 | static void do_dbs_timer(struct work_struct *work) |
32ee8c3e | 545 | { |
529af7a1 VP |
546 | struct cpu_dbs_info_s *dbs_info = |
547 | container_of(work, struct cpu_dbs_info_s, work.work); | |
548 | unsigned int cpu = dbs_info->cpu; | |
549 | int sample_type = dbs_info->sample_type; | |
550 | ||
5cb2c3bd | 551 | int delay; |
a665df9d | 552 | |
5a75c828 | 553 | mutex_lock(&dbs_info->timer_mutex); |
56463b78 | 554 | |
05ca0350 | 555 | /* Common NORMAL_SAMPLE setup */ |
c4028958 | 556 | dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
05ca0350 | 557 | if (!dbs_tuners_ins.powersave_bias || |
c4028958 | 558 | sample_type == DBS_NORMAL_SAMPLE) { |
05ca0350 | 559 | dbs_check_cpu(dbs_info); |
05ca0350 AS |
560 | if (dbs_info->freq_lo) { |
561 | /* Setup timer for SUB_SAMPLE */ | |
c4028958 | 562 | dbs_info->sample_type = DBS_SUB_SAMPLE; |
05ca0350 | 563 | delay = dbs_info->freq_hi_jiffies; |
5cb2c3bd VG |
564 | } else { |
565 | /* We want all CPUs to do sampling nearly on | |
566 | * same jiffy | |
567 | */ | |
568 | delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate | |
569 | * dbs_info->rate_mult); | |
570 | ||
571 | if (num_online_cpus() > 1) | |
572 | delay -= jiffies % delay; | |
05ca0350 AS |
573 | } |
574 | } else { | |
575 | __cpufreq_driver_target(dbs_info->cur_policy, | |
2b03f891 | 576 | dbs_info->freq_lo, CPUFREQ_RELATION_H); |
5cb2c3bd | 577 | delay = dbs_info->freq_lo_jiffies; |
05ca0350 | 578 | } |
57df5573 | 579 | schedule_delayed_work_on(cpu, &dbs_info->work, delay); |
5a75c828 | 580 | mutex_unlock(&dbs_info->timer_mutex); |
32ee8c3e | 581 | } |
1da177e4 | 582 | |
529af7a1 | 583 | static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) |
1da177e4 | 584 | { |
1ce28d6b AS |
585 | /* We want all CPUs to do sampling nearly on same jiffy */ |
586 | int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); | |
a665df9d JF |
587 | |
588 | if (num_online_cpus() > 1) | |
589 | delay -= jiffies % delay; | |
2f8a835c | 590 | |
c4028958 | 591 | dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
28287033 | 592 | INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); |
57df5573 | 593 | schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, delay); |
1da177e4 LT |
594 | } |
595 | ||
2cd7cbdf | 596 | static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) |
1da177e4 | 597 | { |
b14893a6 | 598 | cancel_delayed_work_sync(&dbs_info->work); |
1da177e4 LT |
599 | } |
600 | ||
19379b11 AV |
601 | /* |
602 | * Not all CPUs want IO time to be accounted as busy; this dependson how | |
603 | * efficient idling at a higher frequency/voltage is. | |
604 | * Pavel Machek says this is not so for various generations of AMD and old | |
605 | * Intel systems. | |
606 | * Mike Chan (androidlcom) calis this is also not true for ARM. | |
607 | * Because of this, whitelist specific known (series) of CPUs by default, and | |
608 | * leave all others up to the user. | |
609 | */ | |
610 | static int should_io_be_busy(void) | |
611 | { | |
612 | #if defined(CONFIG_X86) | |
613 | /* | |
614 | * For Intel, Core 2 (model 15) andl later have an efficient idle. | |
615 | */ | |
616 | if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && | |
617 | boot_cpu_data.x86 == 6 && | |
618 | boot_cpu_data.x86_model >= 15) | |
619 | return 1; | |
620 | #endif | |
621 | return 0; | |
622 | } | |
623 | ||
1da177e4 LT |
624 | static int cpufreq_governor_dbs(struct cpufreq_policy *policy, |
625 | unsigned int event) | |
626 | { | |
627 | unsigned int cpu = policy->cpu; | |
628 | struct cpu_dbs_info_s *this_dbs_info; | |
629 | unsigned int j; | |
914f7c31 | 630 | int rc; |
1da177e4 | 631 | |
245b2e70 | 632 | this_dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
1da177e4 LT |
633 | |
634 | switch (event) { | |
635 | case CPUFREQ_GOV_START: | |
ffac80e9 | 636 | if ((!cpu_online(cpu)) || (!policy->cur)) |
1da177e4 LT |
637 | return -EINVAL; |
638 | ||
3fc54d37 | 639 | mutex_lock(&dbs_mutex); |
914f7c31 | 640 | |
5a75c828 | 641 | dbs_enable++; |
835481d9 | 642 | for_each_cpu(j, policy->cpus) { |
1da177e4 | 643 | struct cpu_dbs_info_s *j_dbs_info; |
245b2e70 | 644 | j_dbs_info = &per_cpu(od_cpu_dbs_info, j); |
1da177e4 | 645 | j_dbs_info->cur_policy = policy; |
32ee8c3e | 646 | |
3430502d | 647 | j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j, |
648 | &j_dbs_info->prev_cpu_wall); | |
1ca3abdb VP |
649 | if (dbs_tuners_ins.ignore_nice) { |
650 | j_dbs_info->prev_cpu_nice = | |
651 | kstat_cpu(j).cpustat.nice; | |
652 | } | |
1da177e4 | 653 | } |
529af7a1 | 654 | this_dbs_info->cpu = cpu; |
3f78a9f7 | 655 | this_dbs_info->rate_mult = 1; |
5a75c828 | 656 | ondemand_powersave_bias_init_cpu(cpu); |
1da177e4 LT |
657 | /* |
658 | * Start the timerschedule work, when this governor | |
659 | * is used for first time | |
660 | */ | |
661 | if (dbs_enable == 1) { | |
662 | unsigned int latency; | |
0e625ac1 TR |
663 | |
664 | rc = sysfs_create_group(cpufreq_global_kobject, | |
665 | &dbs_attr_group); | |
666 | if (rc) { | |
667 | mutex_unlock(&dbs_mutex); | |
668 | return rc; | |
669 | } | |
670 | ||
1da177e4 | 671 | /* policy latency is in nS. Convert it to uS first */ |
df8b59be DJ |
672 | latency = policy->cpuinfo.transition_latency / 1000; |
673 | if (latency == 0) | |
674 | latency = 1; | |
cef9615a TR |
675 | /* Bring kernel and HW constraints together */ |
676 | min_sampling_rate = max(min_sampling_rate, | |
677 | MIN_LATENCY_MULTIPLIER * latency); | |
678 | dbs_tuners_ins.sampling_rate = | |
679 | max(min_sampling_rate, | |
680 | latency * LATENCY_MULTIPLIER); | |
19379b11 | 681 | dbs_tuners_ins.io_is_busy = should_io_be_busy(); |
1da177e4 | 682 | } |
3fc54d37 | 683 | mutex_unlock(&dbs_mutex); |
7d26e2d5 | 684 | |
0e625ac1 | 685 | mutex_init(&this_dbs_info->timer_mutex); |
7d26e2d5 | 686 | dbs_timer_init(this_dbs_info); |
1da177e4 LT |
687 | break; |
688 | ||
689 | case CPUFREQ_GOV_STOP: | |
2cd7cbdf | 690 | dbs_timer_exit(this_dbs_info); |
7d26e2d5 | 691 | |
692 | mutex_lock(&dbs_mutex); | |
5a75c828 | 693 | mutex_destroy(&this_dbs_info->timer_mutex); |
1da177e4 | 694 | dbs_enable--; |
3fc54d37 | 695 | mutex_unlock(&dbs_mutex); |
0e625ac1 TR |
696 | if (!dbs_enable) |
697 | sysfs_remove_group(cpufreq_global_kobject, | |
698 | &dbs_attr_group); | |
1da177e4 LT |
699 | |
700 | break; | |
701 | ||
702 | case CPUFREQ_GOV_LIMITS: | |
5a75c828 | 703 | mutex_lock(&this_dbs_info->timer_mutex); |
1da177e4 | 704 | if (policy->max < this_dbs_info->cur_policy->cur) |
ffac80e9 | 705 | __cpufreq_driver_target(this_dbs_info->cur_policy, |
2b03f891 | 706 | policy->max, CPUFREQ_RELATION_H); |
1da177e4 | 707 | else if (policy->min > this_dbs_info->cur_policy->cur) |
ffac80e9 | 708 | __cpufreq_driver_target(this_dbs_info->cur_policy, |
2b03f891 | 709 | policy->min, CPUFREQ_RELATION_L); |
5a75c828 | 710 | mutex_unlock(&this_dbs_info->timer_mutex); |
1da177e4 LT |
711 | break; |
712 | } | |
713 | return 0; | |
714 | } | |
715 | ||
1da177e4 LT |
716 | static int __init cpufreq_gov_dbs_init(void) |
717 | { | |
80800913 | 718 | cputime64_t wall; |
4f6e6b9f AR |
719 | u64 idle_time; |
720 | int cpu = get_cpu(); | |
80800913 | 721 | |
4f6e6b9f AR |
722 | idle_time = get_cpu_idle_time_us(cpu, &wall); |
723 | put_cpu(); | |
80800913 | 724 | if (idle_time != -1ULL) { |
725 | /* Idle micro accounting is supported. Use finer thresholds */ | |
726 | dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; | |
727 | dbs_tuners_ins.down_differential = | |
728 | MICRO_FREQUENCY_DOWN_DIFFERENTIAL; | |
cef9615a | 729 | /* |
bd74b32b | 730 | * In nohz/micro accounting case we set the minimum frequency |
cef9615a TR |
731 | * not depending on HZ, but fixed (very low). The deferred |
732 | * timer might skip some samples if idle/sleeping as needed. | |
733 | */ | |
734 | min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE; | |
735 | } else { | |
736 | /* For correct statistics, we need 10 ticks for each measure */ | |
737 | min_sampling_rate = | |
738 | MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); | |
80800913 | 739 | } |
888a794c | 740 | |
57df5573 | 741 | return cpufreq_register_governor(&cpufreq_gov_ondemand); |
1da177e4 LT |
742 | } |
743 | ||
744 | static void __exit cpufreq_gov_dbs_exit(void) | |
745 | { | |
1c256245 | 746 | cpufreq_unregister_governor(&cpufreq_gov_ondemand); |
1da177e4 LT |
747 | } |
748 | ||
749 | ||
ffac80e9 VP |
750 | MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); |
751 | MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); | |
752 | MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " | |
2b03f891 | 753 | "Low Latency Frequency Transition capable processors"); |
ffac80e9 | 754 | MODULE_LICENSE("GPL"); |
1da177e4 | 755 | |
6915719b JW |
756 | #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
757 | fs_initcall(cpufreq_gov_dbs_init); | |
758 | #else | |
1da177e4 | 759 | module_init(cpufreq_gov_dbs_init); |
6915719b | 760 | #endif |
1da177e4 | 761 | module_exit(cpufreq_gov_dbs_exit); |