unsigned int requested_freq;
int cpu;
unsigned int enable:1;
+ /*
+ * percpu mutex that serializes governor limit change with
+ * do_dbs_timer invocation. We do not want do_dbs_timer to run
+ * when user is changing the governor or limits.
+ */
+ struct mutex timer_mutex;
};
-static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info);
+static DEFINE_PER_CPU(struct cpu_dbs_info_s, cs_cpu_dbs_info);
static unsigned int dbs_enable; /* number of CPUs using this policy */
/*
- * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug
- * lock and dbs_mutex. cpu_hotplug lock should always be held before
- * dbs_mutex. If any function that can potentially take cpu_hotplug lock
- * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then
- * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock
- * is recursive for the same process. -Venki
- * DEADLOCK ALERT! (2) : do_dbs_timer() must not take the dbs_mutex, because it
- * would deadlock with cancel_delayed_work_sync(), which is needed for proper
- * raceless workqueue teardown.
+ * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on
+ * different CPUs. It protects dbs_enable in governor start/stop.
*/
static DEFINE_MUTEX(dbs_mutex);
idle_time = cputime64_sub(cur_wall_time, busy_time);
if (wall)
- *wall = cur_wall_time;
+ *wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);
- return idle_time;
+ return (cputime64_t)jiffies_to_usecs(idle_time);;
}
static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
void *data)
{
struct cpufreq_freqs *freq = data;
- struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info,
+ struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cs_cpu_dbs_info,
freq->cpu);
struct cpufreq_policy *policy;
/************************** sysfs interface ************************/
static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf)
{
- static int print_once;
-
- if (!print_once) {
- printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
- "sysfs file is deprecated - used by: %s\n",
- current->comm);
- print_once = 1;
- }
+ printk_once(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
+ "sysfs file is deprecated - used by: %s\n", current->comm);
return sprintf(buf, "%u\n", -1U);
}
static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf)
{
- static int print_once;
-
- if (!print_once) {
- printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max "
- "sysfs file is deprecated - used by: %s\n", current->comm);
- print_once = 1;
- }
return sprintf(buf, "%u\n", min_sampling_rate);
}
/* we need to re-evaluate prev_cpu_idle */
for_each_online_cpu(j) {
struct cpu_dbs_info_s *dbs_info;
- dbs_info = &per_cpu(cpu_dbs_info, j);
+ dbs_info = &per_cpu(cs_cpu_dbs_info, j);
dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
&dbs_info->prev_cpu_wall);
if (dbs_tuners_ins.ignore_nice)
cputime64_t cur_wall_time, cur_idle_time;
unsigned int idle_time, wall_time;
- j_dbs_info = &per_cpu(cpu_dbs_info, j);
+ j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
delay -= jiffies % delay;
- if (lock_policy_rwsem_write(cpu) < 0)
- return;
-
- if (!dbs_info->enable) {
- unlock_policy_rwsem_write(cpu);
- return;
- }
+ mutex_lock(&dbs_info->timer_mutex);
dbs_check_cpu(dbs_info);
queue_delayed_work_on(cpu, kconservative_wq, &dbs_info->work, delay);
- unlock_policy_rwsem_write(cpu);
+ mutex_unlock(&dbs_info->timer_mutex);
}
static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
unsigned int j;
int rc;
- this_dbs_info = &per_cpu(cpu_dbs_info, cpu);
+ this_dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
switch (event) {
case CPUFREQ_GOV_START:
if ((!cpu_online(cpu)) || (!policy->cur))
return -EINVAL;
- if (this_dbs_info->enable) /* Already enabled */
- break;
-
mutex_lock(&dbs_mutex);
rc = sysfs_create_group(&policy->kobj, &dbs_attr_group);
for_each_cpu(j, policy->cpus) {
struct cpu_dbs_info_s *j_dbs_info;
- j_dbs_info = &per_cpu(cpu_dbs_info, j);
+ j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
j_dbs_info->cur_policy = policy;
j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
this_dbs_info->down_skip = 0;
this_dbs_info->requested_freq = policy->cur;
+ mutex_init(&this_dbs_info->timer_mutex);
dbs_enable++;
/*
* Start the timerschedule work, when this governor
&dbs_cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}
- dbs_timer_init(this_dbs_info);
-
mutex_unlock(&dbs_mutex);
+ dbs_timer_init(this_dbs_info);
+
break;
case CPUFREQ_GOV_STOP:
- mutex_lock(&dbs_mutex);
dbs_timer_exit(this_dbs_info);
+
+ mutex_lock(&dbs_mutex);
sysfs_remove_group(&policy->kobj, &dbs_attr_group);
dbs_enable--;
+ mutex_destroy(&this_dbs_info->timer_mutex);
/*
* Stop the timerschedule work, when this governor
break;
case CPUFREQ_GOV_LIMITS:
- mutex_lock(&dbs_mutex);
+ mutex_lock(&this_dbs_info->timer_mutex);
if (policy->max < this_dbs_info->cur_policy->cur)
__cpufreq_driver_target(
this_dbs_info->cur_policy,
__cpufreq_driver_target(
this_dbs_info->cur_policy,
policy->min, CPUFREQ_RELATION_L);
- mutex_unlock(&dbs_mutex);
+ mutex_unlock(&this_dbs_info->timer_mutex);
break;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff