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Commit 40caf722 authored by Rohit Gupta's avatar Rohit Gupta Committed by Tapas Kumar Kundu
Browse files

soc: qcom: msm_perf: Offline cores based on their power cost 



Some CPUs might have higher operating power costs than others.
While honoring hotplug requests, offline cores with higher power
costs than others within a cluster.
Fallback to the conventional way of offlining CPUs if the power
costs for CPUs are unavaialable.

Change-Id: Ia970bbe751ef5ffbc716ab5d8a7069ee373d8846
Signed-off-by: default avatarRohit Gupta <rohgup@codeaurora.org>
parent 57867645

drivers/soc/qcom/msm_performance.c

+85 −2
Original line number Diff line number Diff line
@@ -46,6 +46,9 @@ static DEFINE_PER_CPU(struct cpu_status, cpu_stats); 


static unsigned int num_online_managed(struct cpumask *mask);

static int init_cluster_control(void);

static int rm_high_pwr_cost_cpus(struct cpu_hp *cl);



static DEFINE_PER_CPU(unsigned int, cpu_power_cost);



static int set_num_clusters(const char *buf, const struct kernel_param *kp)

{
@@ -89,7 +92,7 @@ static int set_max_cpus(const char *buf, const struct kernel_param *kp) 
	while ((cp = strpbrk(cp + 1, ":")))

		ntokens++;



	if (!ntokens)

	if (ntokens != (num_clusters - 1))

		return -EINVAL;



	cp = buf;
@@ -415,6 +418,77 @@ static struct notifier_block perf_cpufreq_nb = { 
	.notifier_call = perf_adjust_notify,

};



/*

 * Attempt to offline CPUs based on their power cost.

 * CPUs with higher power costs are offlined first.

 */

static int __ref rm_high_pwr_cost_cpus(struct cpu_hp *cl)

{

	unsigned int cpu, i;

	struct cpu_pwr_stats *per_cpu_info = get_cpu_pwr_stats();

	struct cpu_pstate_pwr *costs;

	unsigned int *pcpu_pwr;

	unsigned int max_cost_cpu, max_cost;

	int any_cpu = -1;



	if (!per_cpu_info)

		return -ENOSYS;



	for_each_cpu(cpu, cl->cpus) {

		costs = per_cpu_info[cpu].ptable;

		if (!costs || !costs[0].freq)

			continue;



		i = 1;

		while (costs[i].freq)

			i++;



		pcpu_pwr = &per_cpu(cpu_power_cost, cpu);

		*pcpu_pwr = costs[i - 1].power;

		any_cpu = (int)cpu;

		pr_debug("msm_perf: CPU:%d Power:%u\n", cpu, *pcpu_pwr);

	}



	if (any_cpu < 0)

		return -EAGAIN;



	for (i = 0; i < cpumask_weight(cl->cpus); i++) {

		max_cost = 0;

		max_cost_cpu = cpumask_first(cl->cpus);



		for_each_cpu(cpu, cl->cpus) {

			pcpu_pwr = &per_cpu(cpu_power_cost, cpu);

			if (max_cost < *pcpu_pwr) {

				max_cost = *pcpu_pwr;

				max_cost_cpu = cpu;

			}

		}



		if (!cpu_online(max_cost_cpu))

			goto end;



		pr_debug("msm_perf: Offlining CPU%d Power:%d\n", max_cost_cpu,

								max_cost);

		cpumask_set_cpu(max_cost_cpu, cl->offlined_cpus);

		if (cpu_down(max_cost_cpu)) {

			cpumask_clear_cpu(max_cost_cpu, cl->offlined_cpus);

			pr_debug("msm_perf: Offlining CPU%d failed\n",

								max_cost_cpu);

		}



end:

		pcpu_pwr = &per_cpu(cpu_power_cost, max_cost_cpu);

		*pcpu_pwr = 0;

		if (num_online_managed(cl->cpus) <= cl->max_cpu_request)

			break;

	}



	if (num_online_managed(cl->cpus) > cl->max_cpu_request)

		return -EAGAIN;

	else

		return 0;

}



/*

 * try_hotplug tries to online/offline cores based on the current requirement.

 * It loops through the currently managed CPUs and tries to online/offline
@@ -429,6 +503,15 @@ static void __ref try_hotplug(struct cpu_hp *data) 


	mutex_lock(&managed_cpus_lock);

	if (num_online_managed(data->cpus) > data->max_cpu_request) {

		if (!rm_high_pwr_cost_cpus(data)) {

			mutex_unlock(&managed_cpus_lock);

			return;

		}



		/*

		 * If power aware offlining fails due to power cost info

		 * being unavaiable fall back to original implementation

		 */

		for (i = num_present_cpus() - 1; i >= 0; i--) {

			if (!cpumask_test_cpu(i, data->cpus) ||	!cpu_online(i))

				continue;
@@ -469,7 +552,7 @@ static void __ref release_cluster_control(struct cpumask *off_cpus) 
	int cpu;



	for_each_cpu(cpu, off_cpus) {

		pr_err("msm_perf: Release CPU %d\n", cpu);

		pr_debug("msm_perf: Release CPU %d\n", cpu);

		if (!cpu_up(cpu))

			cpumask_clear_cpu(cpu, off_cpus);

	}