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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/cpu.h> 16 #include <linux/percpu-defs.h> 17 #include <linux/slab.h> 18 #include <linux/tick.h> 19 #include "cpufreq_governor.h" 20 21 /* On-demand governor macros */ 22 #define DEF_FREQUENCY_UP_THRESHOLD (80) 23 #define DEF_SAMPLING_DOWN_FACTOR (1) 24 #define MAX_SAMPLING_DOWN_FACTOR (100000) 25 #define MICRO_FREQUENCY_UP_THRESHOLD (95) 26 #define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000) 27 #define MIN_FREQUENCY_UP_THRESHOLD (11) 28 #define MAX_FREQUENCY_UP_THRESHOLD (100) 29 30 static DEFINE_PER_CPU(struct od_cpu_dbs_info_s, od_cpu_dbs_info); 31 32 static struct od_ops od_ops; 33 34 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND 35 static struct cpufreq_governor cpufreq_gov_ondemand; 36 #endif 37 38 static unsigned int default_powersave_bias; 39 40 static void ondemand_powersave_bias_init_cpu(int cpu) 41 { 42 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); 43 44 dbs_info->freq_table = cpufreq_frequency_get_table(cpu); 45 dbs_info->freq_lo = 0; 46 } 47 48 /* 49 * Not all CPUs want IO time to be accounted as busy; this depends on how 50 * efficient idling at a higher frequency/voltage is. 51 * Pavel Machek says this is not so for various generations of AMD and old 52 * Intel systems. 53 * Mike Chan (android.com) claims this is also not true for ARM. 54 * Because of this, whitelist specific known (series) of CPUs by default, and 55 * leave all others up to the user. 56 */ 57 static int should_io_be_busy(void) 58 { 59 #if defined(CONFIG_X86) 60 /* 61 * For Intel, Core 2 (model 15) and later have an efficient idle. 62 */ 63 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && 64 boot_cpu_data.x86 == 6 && 65 boot_cpu_data.x86_model >= 15) 66 return 1; 67 #endif 68 return 0; 69 } 70 71 /* 72 * Find right freq to be set now with powersave_bias on. 73 * Returns the freq_hi to be used right now and will set freq_hi_jiffies, 74 * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs. 75 */ 76 static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy, 77 unsigned int freq_next, unsigned int relation) 78 { 79 unsigned int freq_req, freq_reduc, freq_avg; 80 unsigned int freq_hi, freq_lo; 81 unsigned int index = 0; 82 unsigned int jiffies_total, jiffies_hi, jiffies_lo; 83 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, 84 policy->cpu); 85 struct dbs_data *dbs_data = policy->governor_data; 86 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 87 88 if (!dbs_info->freq_table) { 89 dbs_info->freq_lo = 0; 90 dbs_info->freq_lo_jiffies = 0; 91 return freq_next; 92 } 93 94 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next, 95 relation, &index); 96 freq_req = dbs_info->freq_table[index].frequency; 97 freq_reduc = freq_req * od_tuners->powersave_bias / 1000; 98 freq_avg = freq_req - freq_reduc; 99 100 /* Find freq bounds for freq_avg in freq_table */ 101 index = 0; 102 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, 103 CPUFREQ_RELATION_H, &index); 104 freq_lo = dbs_info->freq_table[index].frequency; 105 index = 0; 106 cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, 107 CPUFREQ_RELATION_L, &index); 108 freq_hi = dbs_info->freq_table[index].frequency; 109 110 /* Find out how long we have to be in hi and lo freqs */ 111 if (freq_hi == freq_lo) { 112 dbs_info->freq_lo = 0; 113 dbs_info->freq_lo_jiffies = 0; 114 return freq_lo; 115 } 116 jiffies_total = usecs_to_jiffies(od_tuners->sampling_rate); 117 jiffies_hi = (freq_avg - freq_lo) * jiffies_total; 118 jiffies_hi += ((freq_hi - freq_lo) / 2); 119 jiffies_hi /= (freq_hi - freq_lo); 120 jiffies_lo = jiffies_total - jiffies_hi; 121 dbs_info->freq_lo = freq_lo; 122 dbs_info->freq_lo_jiffies = jiffies_lo; 123 dbs_info->freq_hi_jiffies = jiffies_hi; 124 return freq_hi; 125 } 126 127 static void ondemand_powersave_bias_init(void) 128 { 129 int i; 130 for_each_online_cpu(i) { 131 ondemand_powersave_bias_init_cpu(i); 132 } 133 } 134 135 static void dbs_freq_increase(struct cpufreq_policy *policy, unsigned int freq) 136 { 137 struct dbs_data *dbs_data = policy->governor_data; 138 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 139 140 if (od_tuners->powersave_bias) 141 freq = od_ops.powersave_bias_target(policy, freq, 142 CPUFREQ_RELATION_H); 143 else if (policy->cur == policy->max) 144 return; 145 146 __cpufreq_driver_target(policy, freq, od_tuners->powersave_bias ? 147 CPUFREQ_RELATION_L : CPUFREQ_RELATION_H); 148 } 149 150 /* 151 * Every sampling_rate, we check, if current idle time is less than 20% 152 * (default), then we try to increase frequency. Else, we adjust the frequency 153 * proportional to load. 154 */ 155 static void od_check_cpu(int cpu, unsigned int load) 156 { 157 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); 158 struct cpufreq_policy *policy = dbs_info->cdbs.cur_policy; 159 struct dbs_data *dbs_data = policy->governor_data; 160 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 161 162 dbs_info->freq_lo = 0; 163 164 /* Check for frequency increase */ 165 if (load > od_tuners->up_threshold) { 166 /* If switching to max speed, apply sampling_down_factor */ 167 if (policy->cur < policy->max) 168 dbs_info->rate_mult = 169 od_tuners->sampling_down_factor; 170 dbs_freq_increase(policy, policy->max); 171 } else { 172 /* Calculate the next frequency proportional to load */ 173 unsigned int freq_next; 174 freq_next = load * policy->cpuinfo.max_freq / 100; 175 176 /* No longer fully busy, reset rate_mult */ 177 dbs_info->rate_mult = 1; 178 179 if (!od_tuners->powersave_bias) { 180 __cpufreq_driver_target(policy, freq_next, 181 CPUFREQ_RELATION_L); 182 return; 183 } 184 185 freq_next = od_ops.powersave_bias_target(policy, freq_next, 186 CPUFREQ_RELATION_L); 187 __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_L); 188 } 189 } 190 191 static void od_dbs_timer(struct work_struct *work) 192 { 193 struct od_cpu_dbs_info_s *dbs_info = 194 container_of(work, struct od_cpu_dbs_info_s, cdbs.work.work); 195 unsigned int cpu = dbs_info->cdbs.cur_policy->cpu; 196 struct od_cpu_dbs_info_s *core_dbs_info = &per_cpu(od_cpu_dbs_info, 197 cpu); 198 struct dbs_data *dbs_data = dbs_info->cdbs.cur_policy->governor_data; 199 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 200 int delay = 0, sample_type = core_dbs_info->sample_type; 201 bool modify_all = true; 202 203 mutex_lock(&core_dbs_info->cdbs.timer_mutex); 204 if (!need_load_eval(&core_dbs_info->cdbs, od_tuners->sampling_rate)) { 205 modify_all = false; 206 goto max_delay; 207 } 208 209 /* Common NORMAL_SAMPLE setup */ 210 core_dbs_info->sample_type = OD_NORMAL_SAMPLE; 211 if (sample_type == OD_SUB_SAMPLE) { 212 delay = core_dbs_info->freq_lo_jiffies; 213 __cpufreq_driver_target(core_dbs_info->cdbs.cur_policy, 214 core_dbs_info->freq_lo, CPUFREQ_RELATION_H); 215 } else { 216 dbs_check_cpu(dbs_data, cpu); 217 if (core_dbs_info->freq_lo) { 218 /* Setup timer for SUB_SAMPLE */ 219 core_dbs_info->sample_type = OD_SUB_SAMPLE; 220 delay = core_dbs_info->freq_hi_jiffies; 221 } 222 } 223 224 max_delay: 225 if (!delay) 226 delay = delay_for_sampling_rate(od_tuners->sampling_rate 227 * core_dbs_info->rate_mult); 228 229 gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, delay, modify_all); 230 mutex_unlock(&core_dbs_info->cdbs.timer_mutex); 231 } 232 233 /************************** sysfs interface ************************/ 234 static struct common_dbs_data od_dbs_cdata; 235 236 /** 237 * update_sampling_rate - update sampling rate effective immediately if needed. 238 * @new_rate: new sampling rate 239 * 240 * If new rate is smaller than the old, simply updating 241 * dbs_tuners_int.sampling_rate might not be appropriate. For example, if the 242 * original sampling_rate was 1 second and the requested new sampling rate is 10 243 * ms because the user needs immediate reaction from ondemand governor, but not 244 * sure if higher frequency will be required or not, then, the governor may 245 * change the sampling rate too late; up to 1 second later. Thus, if we are 246 * reducing the sampling rate, we need to make the new value effective 247 * immediately. 248 */ 249 static void update_sampling_rate(struct dbs_data *dbs_data, 250 unsigned int new_rate) 251 { 252 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 253 int cpu; 254 255 od_tuners->sampling_rate = new_rate = max(new_rate, 256 dbs_data->min_sampling_rate); 257 258 for_each_online_cpu(cpu) { 259 struct cpufreq_policy *policy; 260 struct od_cpu_dbs_info_s *dbs_info; 261 unsigned long next_sampling, appointed_at; 262 263 policy = cpufreq_cpu_get(cpu); 264 if (!policy) 265 continue; 266 if (policy->governor != &cpufreq_gov_ondemand) { 267 cpufreq_cpu_put(policy); 268 continue; 269 } 270 dbs_info = &per_cpu(od_cpu_dbs_info, cpu); 271 cpufreq_cpu_put(policy); 272 273 mutex_lock(&dbs_info->cdbs.timer_mutex); 274 275 if (!delayed_work_pending(&dbs_info->cdbs.work)) { 276 mutex_unlock(&dbs_info->cdbs.timer_mutex); 277 continue; 278 } 279 280 next_sampling = jiffies + usecs_to_jiffies(new_rate); 281 appointed_at = dbs_info->cdbs.work.timer.expires; 282 283 if (time_before(next_sampling, appointed_at)) { 284 285 mutex_unlock(&dbs_info->cdbs.timer_mutex); 286 cancel_delayed_work_sync(&dbs_info->cdbs.work); 287 mutex_lock(&dbs_info->cdbs.timer_mutex); 288 289 gov_queue_work(dbs_data, dbs_info->cdbs.cur_policy, 290 usecs_to_jiffies(new_rate), true); 291 292 } 293 mutex_unlock(&dbs_info->cdbs.timer_mutex); 294 } 295 } 296 297 static ssize_t store_sampling_rate(struct dbs_data *dbs_data, const char *buf, 298 size_t count) 299 { 300 unsigned int input; 301 int ret; 302 ret = sscanf(buf, "%u", &input); 303 if (ret != 1) 304 return -EINVAL; 305 306 update_sampling_rate(dbs_data, input); 307 return count; 308 } 309 310 static ssize_t store_io_is_busy(struct dbs_data *dbs_data, const char *buf, 311 size_t count) 312 { 313 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 314 unsigned int input; 315 int ret; 316 unsigned int j; 317 318 ret = sscanf(buf, "%u", &input); 319 if (ret != 1) 320 return -EINVAL; 321 od_tuners->io_is_busy = !!input; 322 323 /* we need to re-evaluate prev_cpu_idle */ 324 for_each_online_cpu(j) { 325 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, 326 j); 327 dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j, 328 &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy); 329 } 330 return count; 331 } 332 333 static ssize_t store_up_threshold(struct dbs_data *dbs_data, const char *buf, 334 size_t count) 335 { 336 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 337 unsigned int input; 338 int ret; 339 ret = sscanf(buf, "%u", &input); 340 341 if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || 342 input < MIN_FREQUENCY_UP_THRESHOLD) { 343 return -EINVAL; 344 } 345 346 od_tuners->up_threshold = input; 347 return count; 348 } 349 350 static ssize_t store_sampling_down_factor(struct dbs_data *dbs_data, 351 const char *buf, size_t count) 352 { 353 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 354 unsigned int input, j; 355 int ret; 356 ret = sscanf(buf, "%u", &input); 357 358 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) 359 return -EINVAL; 360 od_tuners->sampling_down_factor = input; 361 362 /* Reset down sampling multiplier in case it was active */ 363 for_each_online_cpu(j) { 364 struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, 365 j); 366 dbs_info->rate_mult = 1; 367 } 368 return count; 369 } 370 371 static ssize_t store_ignore_nice_load(struct dbs_data *dbs_data, 372 const char *buf, size_t count) 373 { 374 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 375 unsigned int input; 376 int ret; 377 378 unsigned int j; 379 380 ret = sscanf(buf, "%u", &input); 381 if (ret != 1) 382 return -EINVAL; 383 384 if (input > 1) 385 input = 1; 386 387 if (input == od_tuners->ignore_nice_load) { /* nothing to do */ 388 return count; 389 } 390 od_tuners->ignore_nice_load = input; 391 392 /* we need to re-evaluate prev_cpu_idle */ 393 for_each_online_cpu(j) { 394 struct od_cpu_dbs_info_s *dbs_info; 395 dbs_info = &per_cpu(od_cpu_dbs_info, j); 396 dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j, 397 &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy); 398 if (od_tuners->ignore_nice_load) 399 dbs_info->cdbs.prev_cpu_nice = 400 kcpustat_cpu(j).cpustat[CPUTIME_NICE]; 401 402 } 403 return count; 404 } 405 406 static ssize_t store_powersave_bias(struct dbs_data *dbs_data, const char *buf, 407 size_t count) 408 { 409 struct od_dbs_tuners *od_tuners = dbs_data->tuners; 410 unsigned int input; 411 int ret; 412 ret = sscanf(buf, "%u", &input); 413 414 if (ret != 1) 415 return -EINVAL; 416 417 if (input > 1000) 418 input = 1000; 419 420 od_tuners->powersave_bias = input; 421 ondemand_powersave_bias_init(); 422 return count; 423 } 424 425 show_store_one(od, sampling_rate); 426 show_store_one(od, io_is_busy); 427 show_store_one(od, up_threshold); 428 show_store_one(od, sampling_down_factor); 429 show_store_one(od, ignore_nice_load); 430 show_store_one(od, powersave_bias); 431 declare_show_sampling_rate_min(od); 432 433 gov_sys_pol_attr_rw(sampling_rate); 434 gov_sys_pol_attr_rw(io_is_busy); 435 gov_sys_pol_attr_rw(up_threshold); 436 gov_sys_pol_attr_rw(sampling_down_factor); 437 gov_sys_pol_attr_rw(ignore_nice_load); 438 gov_sys_pol_attr_rw(powersave_bias); 439 gov_sys_pol_attr_ro(sampling_rate_min); 440 441 static struct attribute *dbs_attributes_gov_sys[] = { 442 &sampling_rate_min_gov_sys.attr, 443 &sampling_rate_gov_sys.attr, 444 &up_threshold_gov_sys.attr, 445 &sampling_down_factor_gov_sys.attr, 446 &ignore_nice_load_gov_sys.attr, 447 &powersave_bias_gov_sys.attr, 448 &io_is_busy_gov_sys.attr, 449 NULL 450 }; 451 452 static struct attribute_group od_attr_group_gov_sys = { 453 .attrs = dbs_attributes_gov_sys, 454 .name = "ondemand", 455 }; 456 457 static struct attribute *dbs_attributes_gov_pol[] = { 458 &sampling_rate_min_gov_pol.attr, 459 &sampling_rate_gov_pol.attr, 460 &up_threshold_gov_pol.attr, 461 &sampling_down_factor_gov_pol.attr, 462 &ignore_nice_load_gov_pol.attr, 463 &powersave_bias_gov_pol.attr, 464 &io_is_busy_gov_pol.attr, 465 NULL 466 }; 467 468 static struct attribute_group od_attr_group_gov_pol = { 469 .attrs = dbs_attributes_gov_pol, 470 .name = "ondemand", 471 }; 472 473 /************************** sysfs end ************************/ 474 475 static int od_init(struct dbs_data *dbs_data) 476 { 477 struct od_dbs_tuners *tuners; 478 u64 idle_time; 479 int cpu; 480 481 tuners = kzalloc(sizeof(*tuners), GFP_KERNEL); 482 if (!tuners) { 483 pr_err("%s: kzalloc failed\n", __func__); 484 return -ENOMEM; 485 } 486 487 cpu = get_cpu(); 488 idle_time = get_cpu_idle_time_us(cpu, NULL); 489 put_cpu(); 490 if (idle_time != -1ULL) { 491 /* Idle micro accounting is supported. Use finer thresholds */ 492 tuners->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; 493 /* 494 * In nohz/micro accounting case we set the minimum frequency 495 * not depending on HZ, but fixed (very low). The deferred 496 * timer might skip some samples if idle/sleeping as needed. 497 */ 498 dbs_data->min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE; 499 } else { 500 tuners->up_threshold = DEF_FREQUENCY_UP_THRESHOLD; 501 502 /* For correct statistics, we need 10 ticks for each measure */ 503 dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO * 504 jiffies_to_usecs(10); 505 } 506 507 tuners->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR; 508 tuners->ignore_nice_load = 0; 509 tuners->powersave_bias = default_powersave_bias; 510 tuners->io_is_busy = should_io_be_busy(); 511 512 dbs_data->tuners = tuners; 513 mutex_init(&dbs_data->mutex); 514 return 0; 515 } 516 517 static void od_exit(struct dbs_data *dbs_data) 518 { 519 kfree(dbs_data->tuners); 520 } 521 522 define_get_cpu_dbs_routines(od_cpu_dbs_info); 523 524 static struct od_ops od_ops = { 525 .powersave_bias_init_cpu = ondemand_powersave_bias_init_cpu, 526 .powersave_bias_target = generic_powersave_bias_target, 527 .freq_increase = dbs_freq_increase, 528 }; 529 530 static struct common_dbs_data od_dbs_cdata = { 531 .governor = GOV_ONDEMAND, 532 .attr_group_gov_sys = &od_attr_group_gov_sys, 533 .attr_group_gov_pol = &od_attr_group_gov_pol, 534 .get_cpu_cdbs = get_cpu_cdbs, 535 .get_cpu_dbs_info_s = get_cpu_dbs_info_s, 536 .gov_dbs_timer = od_dbs_timer, 537 .gov_check_cpu = od_check_cpu, 538 .gov_ops = &od_ops, 539 .init = od_init, 540 .exit = od_exit, 541 }; 542 543 static void od_set_powersave_bias(unsigned int powersave_bias) 544 { 545 struct cpufreq_policy *policy; 546 struct dbs_data *dbs_data; 547 struct od_dbs_tuners *od_tuners; 548 unsigned int cpu; 549 cpumask_t done; 550 551 default_powersave_bias = powersave_bias; 552 cpumask_clear(&done); 553 554 get_online_cpus(); 555 for_each_online_cpu(cpu) { 556 if (cpumask_test_cpu(cpu, &done)) 557 continue; 558 559 policy = per_cpu(od_cpu_dbs_info, cpu).cdbs.cur_policy; 560 if (!policy) 561 continue; 562 563 cpumask_or(&done, &done, policy->cpus); 564 565 if (policy->governor != &cpufreq_gov_ondemand) 566 continue; 567 568 dbs_data = policy->governor_data; 569 od_tuners = dbs_data->tuners; 570 od_tuners->powersave_bias = default_powersave_bias; 571 } 572 put_online_cpus(); 573 } 574 575 void od_register_powersave_bias_handler(unsigned int (*f) 576 (struct cpufreq_policy *, unsigned int, unsigned int), 577 unsigned int powersave_bias) 578 { 579 od_ops.powersave_bias_target = f; 580 od_set_powersave_bias(powersave_bias); 581 } 582 EXPORT_SYMBOL_GPL(od_register_powersave_bias_handler); 583 584 void od_unregister_powersave_bias_handler(void) 585 { 586 od_ops.powersave_bias_target = generic_powersave_bias_target; 587 od_set_powersave_bias(0); 588 } 589 EXPORT_SYMBOL_GPL(od_unregister_powersave_bias_handler); 590 591 static int od_cpufreq_governor_dbs(struct cpufreq_policy *policy, 592 unsigned int event) 593 { 594 return cpufreq_governor_dbs(policy, &od_dbs_cdata, event); 595 } 596 597 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND 598 static 599 #endif 600 struct cpufreq_governor cpufreq_gov_ondemand = { 601 .name = "ondemand", 602 .governor = od_cpufreq_governor_dbs, 603 .max_transition_latency = TRANSITION_LATENCY_LIMIT, 604 .owner = THIS_MODULE, 605 }; 606 607 static int __init cpufreq_gov_dbs_init(void) 608 { 609 return cpufreq_register_governor(&cpufreq_gov_ondemand); 610 } 611 612 static void __exit cpufreq_gov_dbs_exit(void) 613 { 614 cpufreq_unregister_governor(&cpufreq_gov_ondemand); 615 } 616 617 MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); 618 MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); 619 MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " 620 "Low Latency Frequency Transition capable processors"); 621 MODULE_LICENSE("GPL"); 622 623 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND 624 fs_initcall(cpufreq_gov_dbs_init); 625 #else 626 module_init(cpufreq_gov_dbs_init); 627 #endif 628 module_exit(cpufreq_gov_dbs_exit); 629