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path: root/drivers/cpufreq/cpufreq_ondemand.c
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Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
-rw-r--r--drivers/cpufreq/cpufreq_ondemand.c28
1 files changed, 20 insertions, 8 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 956d121cb161..3e6ffcaa5af4 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -74,6 +74,8 @@ static unsigned int dbs_enable; /* number of CPUs using this policy */
74static DEFINE_MUTEX (dbs_mutex); 74static DEFINE_MUTEX (dbs_mutex);
75static DECLARE_WORK (dbs_work, do_dbs_timer, NULL); 75static DECLARE_WORK (dbs_work, do_dbs_timer, NULL);
76 76
77static struct workqueue_struct *dbs_workq;
78
77struct dbs_tuners { 79struct dbs_tuners {
78 unsigned int sampling_rate; 80 unsigned int sampling_rate;
79 unsigned int sampling_down_factor; 81 unsigned int sampling_down_factor;
@@ -364,23 +366,29 @@ static void do_dbs_timer(void *data)
364 mutex_lock(&dbs_mutex); 366 mutex_lock(&dbs_mutex);
365 for_each_online_cpu(i) 367 for_each_online_cpu(i)
366 dbs_check_cpu(i); 368 dbs_check_cpu(i);
367 schedule_delayed_work(&dbs_work, 369 queue_delayed_work(dbs_workq, &dbs_work,
368 usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); 370 usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
369 mutex_unlock(&dbs_mutex); 371 mutex_unlock(&dbs_mutex);
370} 372}
371 373
372static inline void dbs_timer_init(void) 374static inline void dbs_timer_init(void)
373{ 375{
374 INIT_WORK(&dbs_work, do_dbs_timer, NULL); 376 INIT_WORK(&dbs_work, do_dbs_timer, NULL);
375 schedule_delayed_work(&dbs_work, 377 if (!dbs_workq)
376 usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); 378 dbs_workq = create_singlethread_workqueue("ondemand");
379 if (!dbs_workq) {
380 printk(KERN_ERR "ondemand: Cannot initialize kernel thread\n");
381 return;
382 }
383 queue_delayed_work(dbs_workq, &dbs_work,
384 usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
377 return; 385 return;
378} 386}
379 387
380static inline void dbs_timer_exit(void) 388static inline void dbs_timer_exit(void)
381{ 389{
382 cancel_delayed_work(&dbs_work); 390 if (dbs_workq)
383 return; 391 cancel_rearming_delayed_workqueue(dbs_workq, &dbs_work);
384} 392}
385 393
386static int cpufreq_governor_dbs(struct cpufreq_policy *policy, 394static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
@@ -489,8 +497,12 @@ static int __init cpufreq_gov_dbs_init(void)
489 497
490static void __exit cpufreq_gov_dbs_exit(void) 498static void __exit cpufreq_gov_dbs_exit(void)
491{ 499{
492 /* Make sure that the scheduled work is indeed not running */ 500 /* Make sure that the scheduled work is indeed not running.
493 flush_scheduled_work(); 501 Assumes the timer has been cancelled first. */
502 if (dbs_workq) {
503 flush_workqueue(dbs_workq);
504 destroy_workqueue(dbs_workq);
505 }
494 506
495 cpufreq_unregister_governor(&cpufreq_gov_dbs); 507 cpufreq_unregister_governor(&cpufreq_gov_dbs);
496} 508}