Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 40d14ffc authored by Junjie Wu's avatar Junjie Wu
Browse files

cpufreq: interactive: Use sched_get_cpus_busy() to query busy time 



sched_get_cpus_busy() provides a snapshot of all CPUs' busy time
information for the set of CPUs being queried. This avoids race
condition due to migration when CPU load is queried one by one.

Change-Id: I6afdfa74ff9f3ef616872df4e2c3bb04f6233c3f
Signed-off-by: default avatarJunjie Wu <junjiew@codeaurora.org>
parent eea23b7c

drivers/cpufreq/cpufreq_interactive.c

+18 −3
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ struct cpufreq_interactive_policyinfo { 
	bool reject_notification;

	int governor_enabled;

	struct cpufreq_interactive_tunables *cached_tunables;

	unsigned long *cpu_busy_times;

};



/* Protected by per-policy load_lock */
@@ -421,7 +422,7 @@ static void __cpufreq_interactive_timer(unsigned long data, bool is_notif) 
	unsigned int index;

	unsigned long flags;

	unsigned long max_cpu;

	int i;

	int i, fcpu;

	struct cpufreq_govinfo govinfo;



	if (!down_read_trylock(&ppol->enable_sem))
@@ -429,16 +430,20 @@ static void __cpufreq_interactive_timer(unsigned long data, bool is_notif) 
	if (!ppol->governor_enabled)

		goto exit;



	fcpu = cpumask_first(ppol->policy->related_cpus);

	now = ktime_to_us(ktime_get());

	spin_lock_irqsave(&ppol->load_lock, flags);

	ppol->last_evaluated_jiffy = get_jiffies_64();



	if (tunables->use_sched_load)

		sched_get_cpus_busy(ppol->cpu_busy_times,

				    ppol->policy->related_cpus);

	max_cpu = cpumask_first(ppol->policy->cpus);

	for_each_cpu(i, ppol->policy->cpus) {

		pcpu = &per_cpu(cpuinfo, i);

		if (tunables->use_sched_load) {

			cputime_speedadj = (u64)sched_get_busy(i) *

				ppol->policy->cpuinfo.max_freq;

			cputime_speedadj = (u64)ppol->cpu_busy_times[i - fcpu]

					* ppol->policy->cpuinfo.max_freq;

			do_div(cputime_speedadj, tunables->timer_rate);

		} else {

			now = update_load(i);
@@ -1446,6 +1451,7 @@ static struct cpufreq_interactive_policyinfo *get_policyinfo( 
	struct cpufreq_interactive_policyinfo *ppol =

				per_cpu(polinfo, policy->cpu);

	int i;

	unsigned long *busy;



	/* polinfo already allocated for policy, return */

	if (ppol)
@@ -1455,6 +1461,14 @@ static struct cpufreq_interactive_policyinfo *get_policyinfo( 
	if (!ppol)

		return ERR_PTR(-ENOMEM);



	busy = kcalloc(cpumask_weight(policy->related_cpus), sizeof(*busy),

		       GFP_KERNEL);

	if (!busy) {

		kfree(ppol);

		return ERR_PTR(-ENOMEM);

	}

	ppol->cpu_busy_times = busy;



	init_timer_deferrable(&ppol->policy_timer);

	ppol->policy_timer.function = cpufreq_interactive_timer;

	init_timer(&ppol->policy_slack_timer);
@@ -1481,6 +1495,7 @@ static void free_policyinfo(int cpu) 
		if (per_cpu(polinfo, j) == ppol)

			per_cpu(polinfo, cpu) = NULL;

	kfree(ppol->cached_tunables);

	kfree(ppol->cpu_busy_times);

	kfree(ppol);

}