(cur_wall_time - j_cdbs->prev_cpu_wall);
j_cdbs->prev_cpu_wall = cur_wall_time;
+ if (cur_idle_time < j_cdbs->prev_cpu_idle)
+ cur_idle_time = j_cdbs->prev_cpu_idle;
+
idle_time = (unsigned int)
(cur_idle_time - j_cdbs->prev_cpu_idle);
j_cdbs->prev_cpu_idle = cur_idle_time;
}
EXPORT_SYMBOL_GPL(dbs_check_cpu);
-static inline void __gov_queue_work(int cpu, struct dbs_data *dbs_data,
- unsigned int delay)
-{
- struct cpu_dbs_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
-
- mod_delayed_work_on(cpu, system_wq, &cdbs->dwork, delay);
-}
-
-void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy,
- unsigned int delay, bool all_cpus)
+void gov_add_timers(struct cpufreq_policy *policy, unsigned int delay)
{
- int i;
+ struct dbs_data *dbs_data = policy->governor_data;
+ struct cpu_dbs_info *cdbs;
+ int cpu;
- if (!all_cpus) {
- /*
- * Use raw_smp_processor_id() to avoid preemptible warnings.
- * We know that this is only called with all_cpus == false from
- * works that have been queued with *_work_on() functions and
- * those works are canceled during CPU_DOWN_PREPARE so they
- * can't possibly run on any other CPU.
- */
- __gov_queue_work(raw_smp_processor_id(), dbs_data, delay);
- } else {
- for_each_cpu(i, policy->cpus)
- __gov_queue_work(i, dbs_data, delay);
+ for_each_cpu(cpu, policy->cpus) {
+ cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
+ cdbs->timer.expires = jiffies + delay;
+ add_timer_on(&cdbs->timer, cpu);
}
}
-EXPORT_SYMBOL_GPL(gov_queue_work);
+EXPORT_SYMBOL_GPL(gov_add_timers);
-static inline void gov_cancel_work(struct dbs_data *dbs_data,
- struct cpufreq_policy *policy)
+static inline void gov_cancel_timers(struct cpufreq_policy *policy)
{
+ struct dbs_data *dbs_data = policy->governor_data;
struct cpu_dbs_info *cdbs;
int i;
for_each_cpu(i, policy->cpus) {
cdbs = dbs_data->cdata->get_cpu_cdbs(i);
- cancel_delayed_work_sync(&cdbs->dwork);
+ del_timer_sync(&cdbs->timer);
}
}
+void gov_cancel_work(struct cpu_common_dbs_info *shared)
+{
+ /* Tell dbs_timer_handler() to skip queuing up work items. */
+ atomic_inc(&shared->skip_work);
+ /*
+ * If dbs_timer_handler() is already running, it may not notice the
+ * incremented skip_work, so wait for it to complete to prevent its work
+ * item from being queued up after the cancel_work_sync() below.
+ */
+ gov_cancel_timers(shared->policy);
+ /*
+ * In case dbs_timer_handler() managed to run and spawn a work item
+ * before the timers have been canceled, wait for that work item to
+ * complete and then cancel all of the timers set up by it. If
+ * dbs_timer_handler() runs again at that point, it will see the
+ * positive value of skip_work and won't spawn any more work items.
+ */
+ cancel_work_sync(&shared->work);
+ gov_cancel_timers(shared->policy);
+ atomic_set(&shared->skip_work, 0);
+}
+EXPORT_SYMBOL_GPL(gov_cancel_work);
+
/* Will return if we need to evaluate cpu load again or not */
static bool need_load_eval(struct cpu_common_dbs_info *shared,
unsigned int sampling_rate)
return true;
}
-static void dbs_timer(struct work_struct *work)
+static void dbs_work_handler(struct work_struct *work)
{
- struct cpu_dbs_info *cdbs = container_of(work, struct cpu_dbs_info,
- dwork.work);
- struct cpu_common_dbs_info *shared = cdbs->shared;
+ struct cpu_common_dbs_info *shared = container_of(work, struct
+ cpu_common_dbs_info, work);
struct cpufreq_policy *policy;
struct dbs_data *dbs_data;
unsigned int sampling_rate, delay;
- bool modify_all = true;
-
- mutex_lock(&shared->timer_mutex);
+ bool eval_load;
policy = shared->policy;
-
- /*
- * Governor might already be disabled and there is no point continuing
- * with the work-handler.
- */
- if (!policy)
- goto unlock;
-
dbs_data = policy->governor_data;
+ /* Kill all timers */
+ gov_cancel_timers(policy);
+
if (dbs_data->cdata->governor == GOV_CONSERVATIVE) {
struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
sampling_rate = od_tuners->sampling_rate;
}
- if (!need_load_eval(cdbs->shared, sampling_rate))
- modify_all = false;
-
- delay = dbs_data->cdata->gov_dbs_timer(policy, modify_all);
- gov_queue_work(dbs_data, policy, delay, modify_all);
+ eval_load = need_load_eval(shared, sampling_rate);
-unlock:
+ /*
+ * Make sure cpufreq_governor_limits() isn't evaluating load in
+ * parallel.
+ */
+ mutex_lock(&shared->timer_mutex);
+ delay = dbs_data->cdata->gov_dbs_timer(policy, eval_load);
mutex_unlock(&shared->timer_mutex);
+
+ atomic_dec(&shared->skip_work);
+
+ gov_add_timers(policy, delay);
+}
+
+static void dbs_timer_handler(unsigned long data)
+{
+ struct cpu_dbs_info *cdbs = (struct cpu_dbs_info *)data;
+ struct cpu_common_dbs_info *shared = cdbs->shared;
+
+ /*
+ * Timer handler may not be allowed to queue the work at the moment,
+ * because:
+ * - Another timer handler has done that
+ * - We are stopping the governor
+ * - Or we are updating the sampling rate of the ondemand governor
+ */
+ if (atomic_inc_return(&shared->skip_work) > 1)
+ atomic_dec(&shared->skip_work);
+ else
+ queue_work(system_wq, &shared->work);
}
static void set_sampling_rate(struct dbs_data *dbs_data,
cdata->get_cpu_cdbs(j)->shared = shared;
mutex_init(&shared->timer_mutex);
+ atomic_set(&shared->skip_work, 0);
+ INIT_WORK(&shared->work, dbs_work_handler);
return 0;
}
if (ignore_nice)
j_cdbs->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
- INIT_DEFERRABLE_WORK(&j_cdbs->dwork, dbs_timer);
+ __setup_timer(&j_cdbs->timer, dbs_timer_handler,
+ (unsigned long)j_cdbs,
+ TIMER_DEFERRABLE | TIMER_IRQSAFE);
}
if (cdata->governor == GOV_CONSERVATIVE) {
od_ops->powersave_bias_init_cpu(cpu);
}
- gov_queue_work(dbs_data, policy, delay_for_sampling_rate(sampling_rate),
- true);
+ gov_add_timers(policy, delay_for_sampling_rate(sampling_rate));
return 0;
}
if (!shared || !shared->policy)
return -EBUSY;
- /*
- * Work-handler must see this updated, as it should not proceed any
- * further after governor is disabled. And so timer_mutex is taken while
- * updating this value.
- */
- mutex_lock(&shared->timer_mutex);
+ gov_cancel_work(shared);
shared->policy = NULL;
- mutex_unlock(&shared->timer_mutex);
- gov_cancel_work(dbs_data, policy);
return 0;
}
projects / cascardo / linux.git / blobdiff