summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--kernel/sched/cpufreq_schedutil.c34
1 files changed, 26 insertions, 8 deletions
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index caf435c14a52..178946e36393 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -92,9 +92,6 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
!cpufreq_this_cpu_can_update(sg_policy->policy))
return false;
- if (sg_policy->work_in_progress)
- return false;
-
if (unlikely(sg_policy->need_freq_update))
return true;
@@ -121,7 +118,7 @@ static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time,
policy->cur = next_freq;
trace_cpu_frequency(next_freq, smp_processor_id());
- } else {
+ } else if (!sg_policy->work_in_progress) {
sg_policy->work_in_progress = true;
irq_work_queue(&sg_policy->irq_work);
}
@@ -366,6 +363,13 @@ static void sugov_update_single(struct update_util_data *hook, u64 time,
ignore_dl_rate_limit(sg_cpu, sg_policy);
+ /*
+ * For slow-switch systems, single policy requests can't run at the
+ * moment if update is in progress, unless we acquire update_lock.
+ */
+ if (sg_policy->work_in_progress)
+ return;
+
if (!sugov_should_update_freq(sg_policy, time))
return;
@@ -440,13 +444,27 @@ sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags)
static void sugov_work(struct kthread_work *work)
{
struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work);
+ unsigned int freq;
+ unsigned long flags;
+
+ /*
+ * Hold sg_policy->update_lock shortly to handle the case where:
+ * incase sg_policy->next_freq is read here, and then updated by
+ * sugov_update_shared just before work_in_progress is set to false
+ * here, we may miss queueing the new update.
+ *
+ * Note: If a work was queued after the update_lock is released,
+ * sugov_work will just be called again by kthread_work code; and the
+ * request will be proceed before the sugov thread sleeps.
+ */
+ raw_spin_lock_irqsave(&sg_policy->update_lock, flags);
+ freq = sg_policy->next_freq;
+ sg_policy->work_in_progress = false;
+ raw_spin_unlock_irqrestore(&sg_policy->update_lock, flags);
mutex_lock(&sg_policy->work_lock);
- __cpufreq_driver_target(sg_policy->policy, sg_policy->next_freq,
- CPUFREQ_RELATION_L);
+ __cpufreq_driver_target(sg_policy->policy, freq, CPUFREQ_RELATION_L);
mutex_unlock(&sg_policy->work_lock);
-
- sg_policy->work_in_progress = false;
}
static void sugov_irq_work(struct irq_work *irq_work)