[PATCH 3/3] cpufreq: schedutil: irq-work is used only in slow path

From: Viresh Kumar
Date: Fri Nov 11 2016 - 05:22:55 EST


Execute the irq-work specific initialization/exit code only when fast
path isn't available.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
kernel/sched/cpufreq_schedutil.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 045ce0a4e6d1..219e717bcd15 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -371,9 +371,9 @@ static void sugov_policy_free(struct sugov_policy *sg_policy)
if (!sg_policy->policy->fast_switch_enabled) {
kthread_flush_worker(&sg_policy->worker);
kthread_stop(sg_policy->thread);
+ mutex_destroy(&sg_policy->work_lock);
}

- mutex_destroy(&sg_policy->work_lock);
kfree(sg_policy);
}

@@ -389,8 +389,6 @@ static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
return NULL;

sg_policy->policy = policy;
- init_irq_work(&sg_policy->irq_work, sugov_irq_work);
- mutex_init(&sg_policy->work_lock);
raw_spin_lock_init(&sg_policy->update_lock);

/* kthread only required for slow path */
@@ -402,7 +400,6 @@ static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
thread = kthread_create(kthread_worker_fn, &sg_policy->worker,
"sugov:%d", cpumask_first(policy->related_cpus));
if (IS_ERR(thread)) {
- mutex_destroy(&sg_policy->work_lock);
kfree(sg_policy);
pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread));
return NULL;
@@ -416,6 +413,9 @@ static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
return NULL;
}

+ init_irq_work(&sg_policy->irq_work, sugov_irq_work);
+ mutex_init(&sg_policy->work_lock);
+
kthread_bind_mask(thread, policy->related_cpus);
wake_up_process(thread);

@@ -578,8 +578,10 @@ static void sugov_stop(struct cpufreq_policy *policy)

synchronize_sched();

- irq_work_sync(&sg_policy->irq_work);
- kthread_cancel_work_sync(&sg_policy->work);
+ if (!policy->fast_switch_enabled) {
+ irq_work_sync(&sg_policy->irq_work);
+ kthread_cancel_work_sync(&sg_policy->work);
+ }
}

static void sugov_limits(struct cpufreq_policy *policy)
--
2.7.1.410.g6faf27b