drivers/cpufreq/cpufreq_interactive.c

   1 /*
   2  * drivers/cpufreq/cpufreq_interactive.c
   3  *
   4  * Copyright (C) 2010 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * Author: Mike Chan (mike@android.com)
  16  *
  17  */
  18
  19 #include <linux/cpu.h>
  20 #include <linux/cpumask.h>
  21 #include <linux/cpufreq.h>
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/rwsem.h>
  25 #include <linux/sched.h>
  26 #include <linux/sched/rt.h>
  27 #include <linux/tick.h>
  28 #include <linux/time.h>
  29 #include <linux/timer.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/kthread.h>
  32 #include <linux/slab.h>
  33 #include "cpufreq_governor.h"
  34
  35 #define CREATE_TRACE_POINTS
  36 #include <trace/events/cpufreq_interactive.h>
  37
  38 struct cpufreq_interactive_cpuinfo {
  39         struct timer_list cpu_timer;
  40         struct timer_list cpu_slack_timer;
  41         spinlock_t load_lock; /* protects the next 4 fields */
  42         u64 time_in_idle;
  43         u64 time_in_idle_timestamp;
  44         u64 cputime_speedadj;
  45         u64 cputime_speedadj_timestamp;
  46         struct cpufreq_policy *policy;
  47         struct cpufreq_frequency_table *freq_table;
  48         unsigned int target_freq;
  49         unsigned int floor_freq;
  50         u64 floor_validate_time;
  51         u64 hispeed_validate_time;
  52         struct rw_semaphore enable_sem;
  53         int governor_enabled;
  54 };
  55
  56 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
  57
  58 /* realtime thread handles frequency scaling */
  59 static struct task_struct *speedchange_task;
  60 static cpumask_t speedchange_cpumask;
  61 static spinlock_t speedchange_cpumask_lock;
  62 static struct mutex gov_lock;
  63
  64 #define DEFAULT_TARGET_LOAD 90
  65 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
  66
  67 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
  68 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
  69 static unsigned int default_above_hispeed_delay[] = {
  70         DEFAULT_ABOVE_HISPEED_DELAY };
  71
  72 struct cpufreq_interactive_tunables {
  73         int usage_count;
  74
  75         /* Hi speed to bump to from lo speed when load burst (default max) */
  76         unsigned int hispeed_freq;
  77
  78         /* Go to hi speed when CPU load at or above this value. */
  79 #define DEFAULT_GO_HISPEED_LOAD 99
  80         unsigned long go_hispeed_load;
  81
  82         /* Target load. Lower values result in higher CPU speeds. */
  83         spinlock_t target_loads_lock;
  84         unsigned int *target_loads;
  85         int ntarget_loads;
  86
  87         /*
  88          * The minimum amount of time to spend at a frequency before we can ramp
  89          * down.
  90          */
  91 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
  92         unsigned long min_sample_time;
  93
  94         /*
  95          * The sample rate of the timer used to increase frequency
  96          */
  97         unsigned long timer_rate;
  98
  99         /*
 100          * Wait this long before raising speed above hispeed, by default a
 101          * single timer interval.
 102          */
 103         spinlock_t above_hispeed_delay_lock;
 104         unsigned int *above_hispeed_delay;
 105         int nabove_hispeed_delay;
 106
 107         /* Non-zero means indefinite speed boost active */
 108         int boost_val;
 109         /* Duration of a boost pulse in usecs */
 110         int boostpulse_duration_val;
 111         /* End time of boost pulse in ktime converted to usecs */
 112         u64 boostpulse_endtime;
 113
 114         /*
 115          * Max additional time to wait in idle, beyond timer_rate, at speeds
 116          * above minimum before wakeup to reduce speed, or -1 if unnecessary.
 117          */
 118 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
 119         int timer_slack_val;
 120
 121         bool io_is_busy;
 122 };
 123
 124 /* For cases where we have single governor instance for system */
 125 struct cpufreq_interactive_tunables *common_tunables;
 126
 127 static struct attribute_group *get_sysfs_attr(void);
 128
 129 static void cpufreq_interactive_timer_resched(
 130         struct cpufreq_interactive_cpuinfo *pcpu)
 131 {
 132         struct cpufreq_interactive_tunables *tunables =
 133                 pcpu->policy->governor_data;
 134         unsigned long expires;
 135         unsigned long flags;
 136
 137         spin_lock_irqsave(&pcpu->load_lock, flags);
 138         pcpu->time_in_idle =
 139                 get_cpu_idle_time(smp_processor_id(),
 140                                      &pcpu->time_in_idle_timestamp,
 141                                      tunables->io_is_busy);
 142         pcpu->cputime_speedadj = 0;
 143         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 144         expires = jiffies + usecs_to_jiffies(tunables->timer_rate);
 145         mod_timer_pinned(&pcpu->cpu_timer, expires);
 146
 147         if (tunables->timer_slack_val >= 0 &&
 148                         pcpu->target_freq > pcpu->policy->min) {
 149                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 150                 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
 151         }
 152
 153         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 154 }
 155
 156 /* The caller shall take enable_sem write semaphore to avoid any timer race.
 157  * The cpu_timer and cpu_slack_timer must be deactivated when calling this
 158  * function.
 159  */
 160 static void cpufreq_interactive_timer_start(
 161                 struct cpufreq_interactive_tunables *tunables, int cpu)
 162 {
 163         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 164         unsigned long expires = jiffies + usecs_to_jiffies(tunables->timer_rate);
 165         unsigned long flags;
 166
 167         pcpu->cpu_timer.expires = expires;
 168         add_timer_on(&pcpu->cpu_timer, cpu);
 169         if (tunables->timer_slack_val >= 0 &&
 170                         pcpu->target_freq > pcpu->policy->min) {
 171                 expires += usecs_to_jiffies(tunables->timer_slack_val);
 172                 pcpu->cpu_slack_timer.expires = expires;
 173                 add_timer_on(&pcpu->cpu_slack_timer, cpu);
 174         }
 175
 176         spin_lock_irqsave(&pcpu->load_lock, flags);
 177         pcpu->time_in_idle =
 178                 get_cpu_idle_time(cpu, &pcpu->time_in_idle_timestamp,
 179                                   tunables->io_is_busy);
 180         pcpu->cputime_speedadj = 0;
 181         pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
 182         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 183 }
 184
 185 static unsigned int freq_to_above_hispeed_delay(
 186                 struct cpufreq_interactive_tunables *tunables,
 187                 unsigned int freq)
 188 {
 189         int i;
 190         unsigned int ret;
 191         unsigned long flags;
 192
 193         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 194
 195         for (i = 0; i < tunables->nabove_hispeed_delay - 1 &&
 196                         freq >= tunables->above_hispeed_delay[i+1]; i += 2)
 197                 ;
 198
 199         ret = tunables->above_hispeed_delay[i];
 200         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 201         return ret;
 202 }
 203
 204 static unsigned int freq_to_targetload(struct cpufreq_interactive_tunables
 205                 *tunables, unsigned int freq)
 206 {
 207         int i;
 208         unsigned int ret;
 209         unsigned long flags;
 210
 211         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 212
 213         for (i = 0; i < tunables->ntarget_loads - 1 &&
 214                         freq >= tunables->target_loads[i+1]; i += 2)
 215                 ;
 216
 217         ret = tunables->target_loads[i];
 218         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 219         return ret;
 220 }
 221
 222 /*
 223  * If increasing frequencies never map to a lower target load then
 224  * choose_freq() will find the minimum frequency that does not exceed its
 225  * target load given the current load.
 226  */
 227 static unsigned int choose_freq(struct cpufreq_interactive_cpuinfo *pcpu,
 228                 unsigned int loadadjfreq)
 229 {
 230         unsigned int freq = pcpu->policy->cur;
 231         unsigned int prevfreq, freqmin, freqmax;
 232         unsigned int tl;
 233         int index;
 234
 235         freqmin = 0;
 236         freqmax = UINT_MAX;
 237
 238         do {
 239                 prevfreq = freq;
 240                 tl = freq_to_targetload(pcpu->policy->governor_data, freq);
 241
 242                 /*
 243                  * Find the lowest frequency where the computed load is less
 244                  * than or equal to the target load.
 245                  */
 246
 247                 if (cpufreq_frequency_table_target(
 248                             pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
 249                             CPUFREQ_RELATION_L, &index))
 250                         break;
 251                 freq = pcpu->freq_table[index].frequency;
 252
 253                 if (freq > prevfreq) {
 254                         /* The previous frequency is too low. */
 255                         freqmin = prevfreq;
 256
 257                         if (freq >= freqmax) {
 258                                 /*
 259                                  * Find the highest frequency that is less
 260                                  * than freqmax.
 261                                  */
 262                                 if (cpufreq_frequency_table_target(
 263                                             pcpu->policy, pcpu->freq_table,
 264                                             freqmax - 1, CPUFREQ_RELATION_H,
 265                                             &index))
 266                                         break;
 267                                 freq = pcpu->freq_table[index].frequency;
 268
 269                                 if (freq == freqmin) {
 270                                         /*
 271                                          * The first frequency below freqmax
 272                                          * has already been found to be too
 273                                          * low.  freqmax is the lowest speed
 274                                          * we found that is fast enough.
 275                                          */
 276                                         freq = freqmax;
 277                                         break;
 278                                 }
 279                         }
 280                 } else if (freq < prevfreq) {
 281                         /* The previous frequency is high enough. */
 282                         freqmax = prevfreq;
 283
 284                         if (freq <= freqmin) {
 285                                 /*
 286                                  * Find the lowest frequency that is higher
 287                                  * than freqmin.
 288                                  */
 289                                 if (cpufreq_frequency_table_target(
 290                                             pcpu->policy, pcpu->freq_table,
 291                                             freqmin + 1, CPUFREQ_RELATION_L,
 292                                             &index))
 293                                         break;
 294                                 freq = pcpu->freq_table[index].frequency;
 295
 296                                 /*
 297                                  * If freqmax is the first frequency above
 298                                  * freqmin then we have already found that
 299                                  * this speed is fast enough.
 300                                  */
 301                                 if (freq == freqmax)
 302                                         break;
 303                         }
 304                 }
 305
 306                 /* If same frequency chosen as previous then done. */
 307         } while (freq != prevfreq);
 308
 309         return freq;
 310 }
 311
 312 static u64 update_load(int cpu)
 313 {
 314         struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
 315         struct cpufreq_interactive_tunables *tunables =
 316                 pcpu->policy->governor_data;
 317         u64 now;
 318         u64 now_idle;
 319         u64 delta_idle;
 320         u64 delta_time;
 321         u64 active_time;
 322
 323         now_idle = get_cpu_idle_time(cpu, &now, tunables->io_is_busy);
 324         delta_idle = (now_idle - pcpu->time_in_idle);
 325         delta_time = (now - pcpu->time_in_idle_timestamp);
 326
 327         if (delta_time <= delta_idle)
 328                 active_time = 0;
 329         else
 330                 active_time = delta_time - delta_idle;
 331
 332         pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
 333
 334         pcpu->time_in_idle = now_idle;
 335         pcpu->time_in_idle_timestamp = now;
 336         return now;
 337 }
 338
 339 static void cpufreq_interactive_timer(unsigned long data)
 340 {
 341         u64 now;
 342         unsigned int delta_time;
 343         u64 cputime_speedadj;
 344         int cpu_load;
 345         struct cpufreq_interactive_cpuinfo *pcpu =
 346                 &per_cpu(cpuinfo, data);
 347         struct cpufreq_interactive_tunables *tunables =
 348                 pcpu->policy->governor_data;
 349         unsigned int new_freq;
 350         unsigned int loadadjfreq;
 351         unsigned int index;
 352         unsigned long flags;
 353         bool boosted;
 354
 355         if (!down_read_trylock(&pcpu->enable_sem))
 356                 return;
 357         if (!pcpu->governor_enabled)
 358                 goto exit;
 359
 360         spin_lock_irqsave(&pcpu->load_lock, flags);
 361         now = update_load(data);
 362         delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
 363         cputime_speedadj = pcpu->cputime_speedadj;
 364         spin_unlock_irqrestore(&pcpu->load_lock, flags);
 365
 366         if (WARN_ON_ONCE(!delta_time))
 367                 goto rearm;
 368
 369         do_div(cputime_speedadj, delta_time);
 370         loadadjfreq = (unsigned int)cputime_speedadj * 100;
 371         cpu_load = loadadjfreq / pcpu->target_freq;
 372         boosted = tunables->boost_val || now < tunables->boostpulse_endtime;
 373
 374         if (cpu_load >= tunables->go_hispeed_load || boosted) {
 375                 if (pcpu->target_freq < tunables->hispeed_freq) {
 376                         new_freq = tunables->hispeed_freq;
 377                 } else {
 378                         new_freq = choose_freq(pcpu, loadadjfreq);
 379
 380                         if (new_freq < tunables->hispeed_freq)
 381                                 new_freq = tunables->hispeed_freq;
 382                 }
 383         } else {
 384                 new_freq = choose_freq(pcpu, loadadjfreq);
 385         }
 386
 387         if (pcpu->target_freq >= tunables->hispeed_freq &&
 388             new_freq > pcpu->target_freq &&
 389             now - pcpu->hispeed_validate_time <
 390             freq_to_above_hispeed_delay(tunables, pcpu->target_freq)) {
 391                 trace_cpufreq_interactive_notyet(
 392                         data, cpu_load, pcpu->target_freq,
 393                         pcpu->policy->cur, new_freq);
 394                 goto rearm;
 395         }
 396
 397         pcpu->hispeed_validate_time = now;
 398
 399         if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
 400                                            new_freq, CPUFREQ_RELATION_L,
 401                                            &index))
 402                 goto rearm;
 403
 404         new_freq = pcpu->freq_table[index].frequency;
 405
 406         /*
 407          * Do not scale below floor_freq unless we have been at or above the
 408          * floor frequency for the minimum sample time since last validated.
 409          */
 410         if (new_freq < pcpu->floor_freq) {
 411                 if (now - pcpu->floor_validate_time <
 412                                 tunables->min_sample_time) {
 413                         trace_cpufreq_interactive_notyet(
 414                                 data, cpu_load, pcpu->target_freq,
 415                                 pcpu->policy->cur, new_freq);
 416                         goto rearm;
 417                 }
 418         }
 419
 420         /*
 421          * Update the timestamp for checking whether speed has been held at
 422          * or above the selected frequency for a minimum of min_sample_time,
 423          * if not boosted to hispeed_freq.  If boosted to hispeed_freq then we
 424          * allow the speed to drop as soon as the boostpulse duration expires
 425          * (or the indefinite boost is turned off).
 426          */
 427
 428         if (!boosted || new_freq > tunables->hispeed_freq) {
 429                 pcpu->floor_freq = new_freq;
 430                 pcpu->floor_validate_time = now;
 431         }
 432
 433         if (pcpu->target_freq == new_freq) {
 434                 trace_cpufreq_interactive_already(
 435                         data, cpu_load, pcpu->target_freq,
 436                         pcpu->policy->cur, new_freq);
 437                 goto rearm_if_notmax;
 438         }
 439
 440         trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
 441                                          pcpu->policy->cur, new_freq);
 442
 443         pcpu->target_freq = new_freq;
 444         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 445         cpumask_set_cpu(data, &speedchange_cpumask);
 446         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 447         wake_up_process(speedchange_task);
 448
 449 rearm_if_notmax:
 450         /*
 451          * Already set max speed and don't see a need to change that,
 452          * wait until next idle to re-evaluate, don't need timer.
 453          */
 454         if (pcpu->target_freq == pcpu->policy->max)
 455                 goto exit;
 456
 457 rearm:
 458         if (!timer_pending(&pcpu->cpu_timer))
 459                 cpufreq_interactive_timer_resched(pcpu);
 460
 461 exit:
 462         up_read(&pcpu->enable_sem);
 463         return;
 464 }
 465
 466 static void cpufreq_interactive_idle_start(void)
 467 {
 468         struct cpufreq_interactive_cpuinfo *pcpu =
 469                 &per_cpu(cpuinfo, smp_processor_id());
 470         int pending;
 471
 472         if (!down_read_trylock(&pcpu->enable_sem))
 473                 return;
 474         if (!pcpu->governor_enabled) {
 475                 up_read(&pcpu->enable_sem);
 476                 return;
 477         }
 478
 479         pending = timer_pending(&pcpu->cpu_timer);
 480
 481         if (pcpu->target_freq != pcpu->policy->min) {
 482                 /*
 483                  * Entering idle while not at lowest speed.  On some
 484                  * platforms this can hold the other CPU(s) at that speed
 485                  * even though the CPU is idle. Set a timer to re-evaluate
 486                  * speed so this idle CPU doesn't hold the other CPUs above
 487                  * min indefinitely.  This should probably be a quirk of
 488                  * the CPUFreq driver.
 489                  */
 490                 if (!pending)
 491                         cpufreq_interactive_timer_resched(pcpu);
 492         }
 493
 494         up_read(&pcpu->enable_sem);
 495 }
 496
 497 static void cpufreq_interactive_idle_end(void)
 498 {
 499         struct cpufreq_interactive_cpuinfo *pcpu =
 500                 &per_cpu(cpuinfo, smp_processor_id());
 501
 502         if (!down_read_trylock(&pcpu->enable_sem))
 503                 return;
 504         if (!pcpu->governor_enabled) {
 505                 up_read(&pcpu->enable_sem);
 506                 return;
 507         }
 508
 509         /* Arm the timer for 1-2 ticks later if not already. */
 510         if (!timer_pending(&pcpu->cpu_timer)) {
 511                 cpufreq_interactive_timer_resched(pcpu);
 512         } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
 513                 del_timer(&pcpu->cpu_timer);
 514                 del_timer(&pcpu->cpu_slack_timer);
 515                 cpufreq_interactive_timer(smp_processor_id());
 516         }
 517
 518         up_read(&pcpu->enable_sem);
 519 }
 520
 521 static int cpufreq_interactive_speedchange_task(void *data)
 522 {
 523         unsigned int cpu;
 524         cpumask_t tmp_mask;
 525         unsigned long flags;
 526         struct cpufreq_interactive_cpuinfo *pcpu;
 527
 528         while (1) {
 529                 set_current_state(TASK_INTERRUPTIBLE);
 530                 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 531
 532                 if (cpumask_empty(&speedchange_cpumask)) {
 533                         spin_unlock_irqrestore(&speedchange_cpumask_lock,
 534                                                flags);
 535                         schedule();
 536
 537                         if (kthread_should_stop())
 538                                 break;
 539
 540                         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 541                 }
 542
 543                 set_current_state(TASK_RUNNING);
 544                 tmp_mask = speedchange_cpumask;
 545                 cpumask_clear(&speedchange_cpumask);
 546                 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 547
 548                 for_each_cpu(cpu, &tmp_mask) {
 549                         unsigned int j;
 550                         unsigned int max_freq = 0;
 551
 552                         pcpu = &per_cpu(cpuinfo, cpu);
 553                         if (!down_read_trylock(&pcpu->enable_sem))
 554                                 continue;
 555                         if (!pcpu->governor_enabled) {
 556                                 up_read(&pcpu->enable_sem);
 557                                 continue;
 558                         }
 559
 560                         for_each_cpu(j, pcpu->policy->cpus) {
 561                                 struct cpufreq_interactive_cpuinfo *pjcpu =
 562                                         &per_cpu(cpuinfo, j);
 563
 564                                 if (pjcpu->target_freq > max_freq)
 565                                         max_freq = pjcpu->target_freq;
 566                         }
 567
 568                         if (max_freq != pcpu->policy->cur)
 569                                 __cpufreq_driver_target(pcpu->policy,
 570                                                         max_freq,
 571                                                         CPUFREQ_RELATION_H);
 572                         trace_cpufreq_interactive_setspeed(cpu,
 573                                                      pcpu->target_freq,
 574                                                      pcpu->policy->cur);
 575
 576                         up_read(&pcpu->enable_sem);
 577                 }
 578         }
 579
 580         return 0;
 581 }
 582
 583 static void cpufreq_interactive_boost(void)
 584 {
 585         int i;
 586         int anyboost = 0;
 587         unsigned long flags;
 588         struct cpufreq_interactive_cpuinfo *pcpu;
 589         struct cpufreq_interactive_tunables *tunables;
 590
 591         spin_lock_irqsave(&speedchange_cpumask_lock, flags);
 592
 593         for_each_online_cpu(i) {
 594                 pcpu = &per_cpu(cpuinfo, i);
 595                 tunables = pcpu->policy->governor_data;
 596
 597                 if (pcpu->target_freq < tunables->hispeed_freq) {
 598                         pcpu->target_freq = tunables->hispeed_freq;
 599                         cpumask_set_cpu(i, &speedchange_cpumask);
 600                         pcpu->hispeed_validate_time =
 601                                 ktime_to_us(ktime_get());
 602                         anyboost = 1;
 603                 }
 604
 605                 /*
 606                  * Set floor freq and (re)start timer for when last
 607                  * validated.
 608                  */
 609
 610                 pcpu->floor_freq = tunables->hispeed_freq;
 611                 pcpu->floor_validate_time = ktime_to_us(ktime_get());
 612         }
 613
 614         spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
 615
 616         if (anyboost)
 617                 wake_up_process(speedchange_task);
 618 }
 619
 620 static int cpufreq_interactive_notifier(
 621         struct notifier_block *nb, unsigned long val, void *data)
 622 {
 623         struct cpufreq_freqs *freq = data;
 624         struct cpufreq_interactive_cpuinfo *pcpu;
 625         int cpu;
 626         unsigned long flags;
 627
 628         if (val == CPUFREQ_POSTCHANGE) {
 629                 pcpu = &per_cpu(cpuinfo, freq->cpu);
 630                 if (!down_read_trylock(&pcpu->enable_sem))
 631                         return 0;
 632                 if (!pcpu->governor_enabled) {
 633                         up_read(&pcpu->enable_sem);
 634                         return 0;
 635                 }
 636
 637                 for_each_cpu(cpu, pcpu->policy->cpus) {
 638                         struct cpufreq_interactive_cpuinfo *pjcpu =
 639                                 &per_cpu(cpuinfo, cpu);
 640                         if (cpu != freq->cpu) {
 641                                 if (!down_read_trylock(&pjcpu->enable_sem))
 642                                         continue;
 643                                 if (!pjcpu->governor_enabled) {
 644                                         up_read(&pjcpu->enable_sem);
 645                                         continue;
 646                                 }
 647                         }
 648                         spin_lock_irqsave(&pjcpu->load_lock, flags);
 649                         update_load(cpu);
 650                         spin_unlock_irqrestore(&pjcpu->load_lock, flags);
 651                         if (cpu != freq->cpu)
 652                                 up_read(&pjcpu->enable_sem);
 653                 }
 654
 655                 up_read(&pcpu->enable_sem);
 656         }
 657         return 0;
 658 }
 659
 660 static struct notifier_block cpufreq_notifier_block = {
 661         .notifier_call = cpufreq_interactive_notifier,
 662 };
 663
 664 static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
 665 {
 666         const char *cp;
 667         int i;
 668         int ntokens = 1;
 669         unsigned int *tokenized_data;
 670         int err = -EINVAL;
 671
 672         cp = buf;
 673         while ((cp = strpbrk(cp + 1, " :")))
 674                 ntokens++;
 675
 676         if (!(ntokens & 0x1))
 677                 goto err;
 678
 679         tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
 680         if (!tokenized_data) {
 681                 err = -ENOMEM;
 682                 goto err;
 683         }
 684
 685         cp = buf;
 686         i = 0;
 687         while (i < ntokens) {
 688                 if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
 689                         goto err_kfree;
 690
 691                 cp = strpbrk(cp, " :");
 692                 if (!cp)
 693                         break;
 694                 cp++;
 695         }
 696
 697         if (i != ntokens)
 698                 goto err_kfree;
 699
 700         *num_tokens = ntokens;
 701         return tokenized_data;
 702
 703 err_kfree:
 704         kfree(tokenized_data);
 705 err:
 706         return ERR_PTR(err);
 707 }
 708
 709 static ssize_t show_target_loads(struct cpufreq_interactive_tunables *tunables,
 710                 char *buf)
 711 {
 712         int i;
 713         ssize_t ret = 0;
 714         unsigned long flags;
 715
 716         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 717
 718         for (i = 0; i < tunables->ntarget_loads; i++)
 719                 ret += sprintf(buf + ret, "%u%s", tunables->target_loads[i],
 720                                i & 0x1 ? ":" : " ");
 721
 722         ret += sprintf(buf + ret, "\n");
 723         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 724         return ret;
 725 }
 726
 727 static ssize_t store_target_loads(struct cpufreq_interactive_tunables *tunables,
 728                 const char *buf, size_t count)
 729 {
 730         int ntokens;
 731         unsigned int *new_target_loads = NULL;
 732         unsigned long flags;
 733
 734         new_target_loads = get_tokenized_data(buf, &ntokens);
 735         if (IS_ERR(new_target_loads))
 736                 return PTR_RET(new_target_loads);
 737
 738         spin_lock_irqsave(&tunables->target_loads_lock, flags);
 739         if (tunables->target_loads != default_target_loads)
 740                 kfree(tunables->target_loads);
 741         tunables->target_loads = new_target_loads;
 742         tunables->ntarget_loads = ntokens;
 743         spin_unlock_irqrestore(&tunables->target_loads_lock, flags);
 744         return count;
 745 }
 746
 747 static ssize_t show_above_hispeed_delay(struct cpufreq_interactive_tunables
 748                 *tunables, char *buf)
 749 {
 750         int i;
 751         ssize_t ret = 0;
 752         unsigned long flags;
 753
 754         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 755
 756         for (i = 0; i < tunables->nabove_hispeed_delay; i++)
 757                 ret += sprintf(buf + ret, "%u%s",
 758                                tunables->above_hispeed_delay[i],
 759                                i & 0x1 ? ":" : " ");
 760
 761         ret += sprintf(buf + ret, "\n");
 762         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 763         return ret;
 764 }
 765
 766 static ssize_t store_above_hispeed_delay(struct cpufreq_interactive_tunables
 767                 *tunables, const char *buf, size_t count)
 768 {
 769         int ntokens;
 770         unsigned int *new_above_hispeed_delay = NULL;
 771         unsigned long flags;
 772
 773         new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
 774         if (IS_ERR(new_above_hispeed_delay))
 775                 return PTR_RET(new_above_hispeed_delay);
 776
 777         spin_lock_irqsave(&tunables->above_hispeed_delay_lock, flags);
 778         if (tunables->above_hispeed_delay != default_above_hispeed_delay)
 779                 kfree(tunables->above_hispeed_delay);
 780         tunables->above_hispeed_delay = new_above_hispeed_delay;
 781         tunables->nabove_hispeed_delay = ntokens;
 782         spin_unlock_irqrestore(&tunables->above_hispeed_delay_lock, flags);
 783         return count;
 784
 785 }
 786
 787 static ssize_t show_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 788                 char *buf)
 789 {
 790         return sprintf(buf, "%u\n", tunables->hispeed_freq);
 791 }
 792
 793 static ssize_t store_hispeed_freq(struct cpufreq_interactive_tunables *tunables,
 794                 const char *buf, size_t count)
 795 {
 796         int ret;
 797         long unsigned int val;
 798
 799         ret = strict_strtoul(buf, 0, &val);
 800         if (ret < 0)
 801                 return ret;
 802         tunables->hispeed_freq = val;
 803         return count;
 804 }
 805
 806 static ssize_t show_go_hispeed_load(struct cpufreq_interactive_tunables
 807                 *tunables, char *buf)
 808 {
 809         return sprintf(buf, "%lu\n", tunables->go_hispeed_load);
 810 }
 811
 812 static ssize_t store_go_hispeed_load(struct cpufreq_interactive_tunables
 813                 *tunables, const char *buf, size_t count)
 814 {
 815         int ret;
 816         unsigned long val;
 817
 818         ret = strict_strtoul(buf, 0, &val);
 819         if (ret < 0)
 820                 return ret;
 821         tunables->go_hispeed_load = val;
 822         return count;
 823 }
 824
 825 static ssize_t show_min_sample_time(struct cpufreq_interactive_tunables
 826                 *tunables, char *buf)
 827 {
 828         return sprintf(buf, "%lu\n", tunables->min_sample_time);
 829 }
 830
 831 static ssize_t store_min_sample_time(struct cpufreq_interactive_tunables
 832                 *tunables, const char *buf, size_t count)
 833 {
 834         int ret;
 835         unsigned long val;
 836
 837         ret = strict_strtoul(buf, 0, &val);
 838         if (ret < 0)
 839                 return ret;
 840         tunables->min_sample_time = val;
 841         return count;
 842 }
 843
 844 static ssize_t show_timer_rate(struct cpufreq_interactive_tunables *tunables,
 845                 char *buf)
 846 {
 847         return sprintf(buf, "%lu\n", tunables->timer_rate);
 848 }
 849
 850 static ssize_t store_timer_rate(struct cpufreq_interactive_tunables *tunables,
 851                 const char *buf, size_t count)
 852 {
 853         int ret;
 854         unsigned long val;
 855
 856         ret = strict_strtoul(buf, 0, &val);
 857         if (ret < 0)
 858                 return ret;
 859         tunables->timer_rate = val;
 860         return count;
 861 }
 862
 863 static ssize_t show_timer_slack(struct cpufreq_interactive_tunables *tunables,
 864                 char *buf)
 865 {
 866         return sprintf(buf, "%d\n", tunables->timer_slack_val);
 867 }
 868
 869 static ssize_t store_timer_slack(struct cpufreq_interactive_tunables *tunables,
 870                 const char *buf, size_t count)
 871 {
 872         int ret;
 873         unsigned long val;
 874
 875         ret = kstrtol(buf, 10, &val);
 876         if (ret < 0)
 877                 return ret;
 878
 879         tunables->timer_slack_val = val;
 880         return count;
 881 }
 882
 883 static ssize_t show_boost(struct cpufreq_interactive_tunables *tunables,
 884                           char *buf)
 885 {
 886         return sprintf(buf, "%d\n", tunables->boost_val);
 887 }
 888
 889 static ssize_t store_boost(struct cpufreq_interactive_tunables *tunables,
 890                            const char *buf, size_t count)
 891 {
 892         int ret;
 893         unsigned long val;
 894
 895         ret = kstrtoul(buf, 0, &val);
 896         if (ret < 0)
 897                 return ret;
 898
 899         tunables->boost_val = val;
 900
 901         if (tunables->boost_val) {
 902                 trace_cpufreq_interactive_boost("on");
 903                 cpufreq_interactive_boost();
 904         } else {
 905                 trace_cpufreq_interactive_unboost("off");
 906         }
 907
 908         return count;
 909 }
 910
 911 static ssize_t store_boostpulse(struct cpufreq_interactive_tunables *tunables,
 912                                 const char *buf, size_t count)
 913 {
 914         int ret;
 915         unsigned long val;
 916
 917         ret = kstrtoul(buf, 0, &val);
 918         if (ret < 0)
 919                 return ret;
 920
 921         tunables->boostpulse_endtime = ktime_to_us(ktime_get()) +
 922                 tunables->boostpulse_duration_val;
 923         trace_cpufreq_interactive_boost("pulse");
 924         cpufreq_interactive_boost();
 925         return count;
 926 }
 927
 928 static ssize_t show_boostpulse_duration(struct cpufreq_interactive_tunables
 929                 *tunables, char *buf)
 930 {
 931         return sprintf(buf, "%d\n", tunables->boostpulse_duration_val);
 932 }
 933
 934 static ssize_t store_boostpulse_duration(struct cpufreq_interactive_tunables
 935                 *tunables, const char *buf, size_t count)
 936 {
 937         int ret;
 938         unsigned long val;
 939
 940         ret = kstrtoul(buf, 0, &val);
 941         if (ret < 0)
 942                 return ret;
 943
 944         tunables->boostpulse_duration_val = val;
 945         return count;
 946 }
 947
 948 static ssize_t show_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 949                 char *buf)
 950 {
 951         return sprintf(buf, "%u\n", tunables->io_is_busy);
 952 }
 953
 954 static ssize_t store_io_is_busy(struct cpufreq_interactive_tunables *tunables,
 955                 const char *buf, size_t count)
 956 {
 957         int ret;
 958         unsigned long val;
 959
 960         ret = kstrtoul(buf, 0, &val);
 961         if (ret < 0)
 962                 return ret;
 963         tunables->io_is_busy = val;
 964         return count;
 965 }
 966
 967 /*
 968  * Create show/store routines
 969  * - sys: One governor instance for complete SYSTEM
 970  * - pol: One governor instance per struct cpufreq_policy
 971  */
 972 #define show_gov_pol_sys(file_name)                                     \
 973 static ssize_t show_##file_name##_gov_sys                               \
 974 (struct kobject *kobj, struct attribute *attr, char *buf)               \
 975 {                                                                       \
 976         return show_##file_name(common_tunables, buf);                  \
 977 }                                                                       \
 978                                                                         \
 979 static ssize_t show_##file_name##_gov_pol                               \
 980 (struct cpufreq_policy *policy, char *buf)                              \
 981 {                                                                       \
 982         return show_##file_name(policy->governor_data, buf);            \
 983 }
 984
 985 #define store_gov_pol_sys(file_name)                                    \
 986 static ssize_t store_##file_name##_gov_sys                              \
 987 (struct kobject *kobj, struct attribute *attr, const char *buf,         \
 988         size_t count)                                                   \
 989 {                                                                       \
 990         return store_##file_name(common_tunables, buf, count);          \
 991 }                                                                       \
 992                                                                         \
 993 static ssize_t store_##file_name##_gov_pol                              \
 994 (struct cpufreq_policy *policy, const char *buf, size_t count)          \
 995 {                                                                       \
 996         return store_##file_name(policy->governor_data, buf, count);    \
 997 }
 998
 999 #define show_store_gov_pol_sys(file_name)                               \
1000 show_gov_pol_sys(file_name);                                            \
1001 store_gov_pol_sys(file_name)
1002
1003 show_store_gov_pol_sys(target_loads);
1004 show_store_gov_pol_sys(above_hispeed_delay);
1005 show_store_gov_pol_sys(hispeed_freq);
1006 show_store_gov_pol_sys(go_hispeed_load);
1007 show_store_gov_pol_sys(min_sample_time);
1008 show_store_gov_pol_sys(timer_rate);
1009 show_store_gov_pol_sys(timer_slack);
1010 show_store_gov_pol_sys(boost);
1011 store_gov_pol_sys(boostpulse);
1012 show_store_gov_pol_sys(boostpulse_duration);
1013 show_store_gov_pol_sys(io_is_busy);
1014
1015 gov_sys_pol_attr_rw(target_loads);
1016 gov_sys_pol_attr_rw(above_hispeed_delay);
1017 gov_sys_pol_attr_rw(hispeed_freq);
1018 gov_sys_pol_attr_rw(go_hispeed_load);
1019 gov_sys_pol_attr_rw(min_sample_time);
1020 gov_sys_pol_attr_rw(timer_rate);
1021 gov_sys_pol_attr_rw(timer_slack);
1022 gov_sys_pol_attr_rw(boost);
1023 gov_sys_pol_attr_rw(boostpulse_duration);
1024 gov_sys_pol_attr_rw(io_is_busy);
1025
1026 static struct global_attr boostpulse_gov_sys =
1027         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_sys);
1028
1029 static struct freq_attr boostpulse_gov_pol =
1030         __ATTR(boostpulse, 0200, NULL, store_boostpulse_gov_pol);
1031
1032 /* One Governor instance for entire system */
1033 static struct attribute *interactive_attributes_gov_sys[] = {
1034         &target_loads_gov_sys.attr,
1035         &above_hispeed_delay_gov_sys.attr,
1036         &hispeed_freq_gov_sys.attr,
1037         &go_hispeed_load_gov_sys.attr,
1038         &min_sample_time_gov_sys.attr,
1039         &timer_rate_gov_sys.attr,
1040         &timer_slack_gov_sys.attr,
1041         &boost_gov_sys.attr,
1042         &boostpulse_gov_sys.attr,
1043         &boostpulse_duration_gov_sys.attr,
1044         &io_is_busy_gov_sys.attr,
1045         NULL,
1046 };
1047
1048 static struct attribute_group interactive_attr_group_gov_sys = {
1049         .attrs = interactive_attributes_gov_sys,
1050         .name = "interactive",
1051 };
1052
1053 /* Per policy governor instance */
1054 static struct attribute *interactive_attributes_gov_pol[] = {
1055         &target_loads_gov_pol.attr,
1056         &above_hispeed_delay_gov_pol.attr,
1057         &hispeed_freq_gov_pol.attr,
1058         &go_hispeed_load_gov_pol.attr,
1059         &min_sample_time_gov_pol.attr,
1060         &timer_rate_gov_pol.attr,
1061         &timer_slack_gov_pol.attr,
1062         &boost_gov_pol.attr,
1063         &boostpulse_gov_pol.attr,
1064         &boostpulse_duration_gov_pol.attr,
1065         &io_is_busy_gov_pol.attr,
1066         NULL,
1067 };
1068
1069 static struct attribute_group interactive_attr_group_gov_pol = {
1070         .attrs = interactive_attributes_gov_pol,
1071         .name = "interactive",
1072 };
1073
1074 static struct attribute_group *get_sysfs_attr(void)
1075 {
1076         if (have_governor_per_policy())
1077                 return &interactive_attr_group_gov_pol;
1078         else
1079                 return &interactive_attr_group_gov_sys;
1080 }
1081
1082 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1083                                              unsigned long val,
1084                                              void *data)
1085 {
1086         switch (val) {
1087         case IDLE_START:
1088                 cpufreq_interactive_idle_start();
1089                 break;
1090         case IDLE_END:
1091                 cpufreq_interactive_idle_end();
1092                 break;
1093         }
1094
1095         return 0;
1096 }
1097
1098 static struct notifier_block cpufreq_interactive_idle_nb = {
1099         .notifier_call = cpufreq_interactive_idle_notifier,
1100 };
1101
1102 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1103                 unsigned int event)
1104 {
1105         int rc;
1106         unsigned int j;
1107         struct cpufreq_interactive_cpuinfo *pcpu;
1108         struct cpufreq_frequency_table *freq_table;
1109         struct cpufreq_interactive_tunables *tunables;
1110
1111         if (have_governor_per_policy())
1112                 tunables = policy->governor_data;
1113         else
1114                 tunables = common_tunables;
1115
1116         WARN_ON(!tunables && (event != CPUFREQ_GOV_POLICY_INIT));
1117
1118         switch (event) {
1119         case CPUFREQ_GOV_POLICY_INIT:
1120                 if (have_governor_per_policy()) {
1121                         WARN_ON(tunables);
1122                 } else if (tunables) {
1123                         tunables->usage_count++;
1124                         policy->governor_data = tunables;
1125                         return 0;
1126                 }
1127
1128                 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
1129                 if (!tunables) {
1130                         pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__);
1131                         return -ENOMEM;
1132                 }
1133
1134                 rc = sysfs_create_group(get_governor_parent_kobj(policy),
1135                                 get_sysfs_attr());
1136                 if (rc) {
1137                         kfree(tunables);
1138                         return rc;
1139                 }
1140
1141                 tunables->usage_count = 1;
1142                 tunables->above_hispeed_delay = default_above_hispeed_delay;
1143                 tunables->nabove_hispeed_delay =
1144                         ARRAY_SIZE(default_above_hispeed_delay);
1145                 tunables->go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
1146                 tunables->target_loads = default_target_loads;
1147                 tunables->ntarget_loads = ARRAY_SIZE(default_target_loads);
1148                 tunables->min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
1149                 tunables->timer_rate = DEFAULT_TIMER_RATE;
1150                 tunables->boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
1151                 tunables->timer_slack_val = DEFAULT_TIMER_SLACK;
1152
1153                 spin_lock_init(&tunables->target_loads_lock);
1154                 spin_lock_init(&tunables->above_hispeed_delay_lock);
1155
1156                 if (!policy->governor->initialized) {
1157                         idle_notifier_register(&cpufreq_interactive_idle_nb);
1158                         cpufreq_register_notifier(&cpufreq_notifier_block,
1159                                         CPUFREQ_TRANSITION_NOTIFIER);
1160                 }
1161
1162                 policy->governor_data = tunables;
1163                 if (!have_governor_per_policy())
1164                         common_tunables = tunables;
1165
1166                 break;
1167
1168         case CPUFREQ_GOV_POLICY_EXIT:
1169                 if (!--tunables->usage_count) {
1170                         if (policy->governor->initialized == 1) {
1171                                 cpufreq_unregister_notifier(&cpufreq_notifier_block,
1172                                                 CPUFREQ_TRANSITION_NOTIFIER);
1173                                 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
1174                         }
1175
1176                         sysfs_remove_group(get_governor_parent_kobj(policy),
1177                                         get_sysfs_attr());
1178                         kfree(tunables);
1179                         common_tunables = NULL;
1180                 }
1181
1182                 policy->governor_data = NULL;
1183                 break;
1184
1185         case CPUFREQ_GOV_START:
1186                 mutex_lock(&gov_lock);
1187
1188                 freq_table = cpufreq_frequency_get_table(policy->cpu);
1189                 if (!tunables->hispeed_freq)
1190                         tunables->hispeed_freq = policy->max;
1191
1192                 for_each_cpu(j, policy->cpus) {
1193                         pcpu = &per_cpu(cpuinfo, j);
1194                         pcpu->policy = policy;
1195                         pcpu->target_freq = policy->cur;
1196                         pcpu->freq_table = freq_table;
1197                         pcpu->floor_freq = pcpu->target_freq;
1198                         pcpu->floor_validate_time =
1199                                 ktime_to_us(ktime_get());
1200                         pcpu->hispeed_validate_time =
1201                                 pcpu->floor_validate_time;
1202                         down_write(&pcpu->enable_sem);
1203                         cpufreq_interactive_timer_start(tunables, j);
1204                         pcpu->governor_enabled = 1;
1205                         up_write(&pcpu->enable_sem);
1206                 }
1207
1208                 mutex_unlock(&gov_lock);
1209                 break;
1210
1211         case CPUFREQ_GOV_STOP:
1212                 mutex_lock(&gov_lock);
1213                 for_each_cpu(j, policy->cpus) {
1214                         pcpu = &per_cpu(cpuinfo, j);
1215                         down_write(&pcpu->enable_sem);
1216                         pcpu->governor_enabled = 0;
1217                         del_timer_sync(&pcpu->cpu_timer);
1218                         del_timer_sync(&pcpu->cpu_slack_timer);
1219                         up_write(&pcpu->enable_sem);
1220                 }
1221
1222                 mutex_unlock(&gov_lock);
1223                 break;
1224
1225         case CPUFREQ_GOV_LIMITS:
1226                 if (policy->max < policy->cur)
1227                         __cpufreq_driver_target(policy,
1228                                         policy->max, CPUFREQ_RELATION_H);
1229                 else if (policy->min > policy->cur)
1230                         __cpufreq_driver_target(policy,
1231                                         policy->min, CPUFREQ_RELATION_L);
1232                 for_each_cpu(j, policy->cpus) {
1233                         pcpu = &per_cpu(cpuinfo, j);
1234
1235                         /* hold write semaphore to avoid race */
1236                         down_write(&pcpu->enable_sem);
1237                         if (pcpu->governor_enabled == 0) {
1238                                 up_write(&pcpu->enable_sem);
1239                                 continue;
1240                         }
1241
1242                         /* update target_freq firstly */
1243                         if (policy->max < pcpu->target_freq)
1244                                 pcpu->target_freq = policy->max;
1245                         else if (policy->min > pcpu->target_freq)
1246                                 pcpu->target_freq = policy->min;
1247
1248                         /* Reschedule timer.
1249                          * Delete the timers, else the timer callback may
1250                          * return without re-arm the timer when failed
1251                          * acquire the semaphore. This race may cause timer
1252                          * stopped unexpectedly.
1253                          */
1254                         del_timer_sync(&pcpu->cpu_timer);
1255                         del_timer_sync(&pcpu->cpu_slack_timer);
1256                         cpufreq_interactive_timer_start(tunables, j);
1257                         up_write(&pcpu->enable_sem);
1258                 }
1259                 break;
1260         }
1261         return 0;
1262 }
1263
1264 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1265 static
1266 #endif
1267 struct cpufreq_governor cpufreq_gov_interactive = {
1268         .name = "interactive",
1269         .governor = cpufreq_governor_interactive,
1270         .max_transition_latency = 10000000,
1271         .owner = THIS_MODULE,
1272 };
1273
1274 static void cpufreq_interactive_nop_timer(unsigned long data)
1275 {
1276 }
1277
1278 static int __init cpufreq_interactive_init(void)
1279 {
1280         unsigned int i;
1281         struct cpufreq_interactive_cpuinfo *pcpu;
1282         struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1283
1284         /* Initalize per-cpu timers */
1285         for_each_possible_cpu(i) {
1286                 pcpu = &per_cpu(cpuinfo, i);
1287                 init_timer_deferrable(&pcpu->cpu_timer);
1288                 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1289                 pcpu->cpu_timer.data = i;
1290                 init_timer(&pcpu->cpu_slack_timer);
1291                 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1292                 spin_lock_init(&pcpu->load_lock);
1293                 init_rwsem(&pcpu->enable_sem);
1294         }
1295
1296         spin_lock_init(&speedchange_cpumask_lock);
1297         mutex_init(&gov_lock);
1298         speedchange_task =
1299                 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1300                                "cfinteractive");
1301         if (IS_ERR(speedchange_task))
1302                 return PTR_ERR(speedchange_task);
1303
1304         sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
1305         get_task_struct(speedchange_task);
1306
1307         /* NB: wake up so the thread does not look hung to the freezer */
1308         wake_up_process(speedchange_task);
1309
1310         return cpufreq_register_governor(&cpufreq_gov_interactive);
1311 }
1312
1313 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1314 fs_initcall(cpufreq_interactive_init);
1315 #else
1316 module_init(cpufreq_interactive_init);
1317 #endif
1318
1319 static void __exit cpufreq_interactive_exit(void)
1320 {
1321         cpufreq_unregister_governor(&cpufreq_gov_interactive);
1322         kthread_stop(speedchange_task);
1323         put_task_struct(speedchange_task);
1324 }
1325
1326 module_exit(cpufreq_interactive_exit);
1327
1328 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1329 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1330         "Latency sensitive workloads");
1331 MODULE_LICENSE("GPL");