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Commit 5465ed86 authored by Satya Durga Srinivasu Prabhala's avatar Satya Durga Srinivasu Prabhala
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sched: Support Energy Aware Scheduling irrespective of governor 



This reverts commit 1e6b1214 ("FROMLIST: sched/topology:
Make Energy Aware Scheduling depend on schedutil").
Right now, EAS gets disabled when governor set to anything other
than schedutil which affects scheduling decisions. To make sure
we always get better scheduling decions, EAS needs to be supported
irrespective of the governor.

Change-Id: I788faaacd477b3ff93ea9787c18a1235c8c3eb0b
Signed-off-by: default avatarSatya Durga Srinivasu Prabhala <satyap@codeaurora.org>
parent 05c45a66

drivers/cpufreq/cpufreq.c

+0 −1
Original line number Diff line number Diff line
@@ -2278,7 +2278,6 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, 
		ret = cpufreq_start_governor(policy);

		if (!ret) {

			pr_debug("cpufreq: governor change\n");

			sched_cpufreq_governor_change(policy, old_gov);

			return 0;

		}

		cpufreq_exit_governor(policy);

kernel/sched/cpufreq_schedutil.c

+2 −35
Original line number Diff line number Diff line
@@ -968,7 +968,7 @@ static struct kobj_type sugov_tunables_ktype = { 


/********************** cpufreq governor interface *********************/



struct cpufreq_governor schedutil_gov;

static struct cpufreq_governor schedutil_gov;



static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)

{
@@ -1285,7 +1285,7 @@ static void sugov_limits(struct cpufreq_policy *policy) 
	sg_policy->need_freq_update = true;

}



struct cpufreq_governor schedutil_gov = {

static struct cpufreq_governor schedutil_gov = {

	.name			= "schedutil",

	.owner			= THIS_MODULE,

	.dynamic_switching	= true,
@@ -1308,36 +1308,3 @@ static int __init sugov_register(void) 
	return cpufreq_register_governor(&schedutil_gov);

}

fs_initcall(sugov_register);
 


#ifdef CONFIG_ENERGY_MODEL

extern bool sched_energy_update;

extern struct mutex sched_energy_mutex;



static void rebuild_sd_workfn(struct work_struct *work)

{

	mutex_lock(&sched_energy_mutex);

	sched_energy_update = true;

	rebuild_sched_domains();

	sched_energy_update = false;

	mutex_unlock(&sched_energy_mutex);

}

static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn);



/*

 * EAS shouldn't be attempted without sugov, so rebuild the sched_domains

 * on governor changes to make sure the scheduler knows about it.

 */

void sched_cpufreq_governor_change(struct cpufreq_policy *policy,

				  struct cpufreq_governor *old_gov)

{

	if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) {

		/*

		 * When called from the cpufreq_register_driver() path, the

		 * cpu_hotplug_lock is already held, so use a work item to

		 * avoid nested locking in rebuild_sched_domains().

		 */

		schedule_work(&rebuild_sd_work);

	}



}

#endif

kernel/sched/sched.h

+1 −1
Original line number Diff line number Diff line
@@ -2659,7 +2659,7 @@ unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned 
}

#endif



#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)

#ifdef CONFIG_ENERGY_MODEL

#define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus)))

#else

#define perf_domain_span(pd) NULL

kernel/sched/topology.c

+4 −23
Original line number Diff line number Diff line
@@ -202,9 +202,7 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) 
}



DEFINE_STATIC_KEY_FALSE(sched_energy_present);

#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)

DEFINE_MUTEX(sched_energy_mutex);

bool sched_energy_update;

#ifdef CONFIG_ENERGY_MODEL



static void free_pd(struct perf_domain *pd)

{
@@ -292,7 +290,6 @@ static void sched_energy_set(bool has_eas) 
 *    1. an Energy Model (EM) is available;

 *    2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy.

 *    3. the EM complexity is low enough to keep scheduling overheads low;

 *    4. schedutil is driving the frequency of all CPUs of the rd;

 *

 * The complexity of the Energy Model is defined as:

 *
@@ -312,15 +309,12 @@ static void sched_energy_set(bool has_eas) 
 */

#define EM_MAX_COMPLEXITY 2048



extern struct cpufreq_governor schedutil_gov;

static bool build_perf_domains(const struct cpumask *cpu_map)

{

	int i, nr_pd = 0, nr_cs = 0, nr_cpus = cpumask_weight(cpu_map);

	struct perf_domain *pd = NULL, *tmp;

	int cpu = cpumask_first(cpu_map);

	struct root_domain *rd = cpu_rq(cpu)->rd;

	struct cpufreq_policy *policy;

	struct cpufreq_governor *gov;



	/* EAS is enabled for asymmetric CPU capacity topologies. */

	if (!per_cpu(sd_asym_cpucapacity, cpu)) {
@@ -336,19 +330,6 @@ static bool build_perf_domains(const struct cpumask *cpu_map) 
		if (find_pd(pd, i))

			continue;



		/* Do not attempt EAS if schedutil is not being used. */

		policy = cpufreq_cpu_get(i);

		if (!policy)

			goto free;

		gov = policy->governor;

		cpufreq_cpu_put(policy);

		if (gov != &schedutil_gov) {

			if (rd->pd)

				pr_warn("rd %*pbl: Disabling EAS, schedutil is mandatory\n",

						cpumask_pr_args(cpu_map));

			goto free;

		}



		/* Create the new pd and add it to the local list. */

		tmp = pd_init(i);

		if (!tmp)
@@ -392,7 +373,7 @@ static bool build_perf_domains(const struct cpumask *cpu_map) 
}

#else

static void free_pd(struct perf_domain *pd) { }

#endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL*/

#endif /* CONFIG_ENERGY_MODEL */



static void free_rootdomain(struct rcu_head *rcu)

{
@@ -2214,10 +2195,10 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], 
		;

	}



#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)

#ifdef CONFIG_ENERGY_MODEL

	/* Build perf. domains: */

	for (i = 0; i < ndoms_new; i++) {

		for (j = 0; j < n && !sched_energy_update; j++) {

		for (j = 0; j < n; j++) {

			if (cpumask_equal(doms_new[i], doms_cur[j]) &&

			    cpu_rq(cpumask_first(doms_cur[j]))->rd->pd) {

				has_eas = true;