Commit 218a06a7 authored by Jie Zhan's avatar Jie Zhan Committed by Rafael J. Wysocki
Browse files

cpufreq: Support per-policy performance boost 



The boost control currently applies to the whole system.  However, users
may prefer to boost a subset of cores in order to provide prioritized
performance to workloads running on the boosted cores.

Enable per-policy boost by adding a 'boost' sysfs interface under each
policy path.  This can be found at:

	/sys/devices/system/cpu/cpufreq/policy<*>/boost

Same to the global boost switch, writing 1/0 to the per-policy 'boost'
enables/disables boost on a cpufreq policy respectively.

The user view of global and per-policy boost controls should be:

1. Enabling global boost initially enables boost on all policies, and
per-policy boost can then be enabled or disabled individually, given that
the platform does support so.

2. Disabling global boost makes the per-policy boost interface illegal.

Signed-off-by: default avatarJie Zhan <zhanjie9@hisilicon.com>
Reviewed-by: default avatarWei Xu <xuwei5@hisilicon.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 4c2fdf73

drivers/cpufreq/cpufreq.c

+43 −0
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ static void cpufreq_governor_limits(struct cpufreq_policy *policy); 
static int cpufreq_set_policy(struct cpufreq_policy *policy,

			      struct cpufreq_governor *new_gov,

			      unsigned int new_pol);

static bool cpufreq_boost_supported(void);



/*

 * Two notifier lists: the "policy" list is involved in the
@@ -623,6 +624,40 @@ static ssize_t store_boost(struct kobject *kobj, struct kobj_attribute *attr, 
}

define_one_global_rw(boost);



static ssize_t show_local_boost(struct cpufreq_policy *policy, char *buf)

{

	return sysfs_emit(buf, "%d\n", policy->boost_enabled);

}



static ssize_t store_local_boost(struct cpufreq_policy *policy,

				 const char *buf, size_t count)

{

	int ret, enable;



	ret = kstrtoint(buf, 10, &enable);

	if (ret || enable < 0 || enable > 1)

		return -EINVAL;



	if (!cpufreq_driver->boost_enabled)

		return -EINVAL;



	if (policy->boost_enabled == enable)

		return count;



	cpus_read_lock();

	ret = cpufreq_driver->set_boost(policy, enable);

	cpus_read_unlock();



	if (ret)

		return ret;



	policy->boost_enabled = enable;



	return count;

}



static struct freq_attr local_boost = __ATTR(boost, 0644, show_local_boost, store_local_boost);



static struct cpufreq_governor *find_governor(const char *str_governor)

{

	struct cpufreq_governor *t;
@@ -1057,6 +1092,12 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) 
			return ret;

	}



	if (cpufreq_boost_supported()) {

		ret = sysfs_create_file(&policy->kobj, &local_boost.attr);

		if (ret)

			return ret;

	}



	return 0;

}
@@ -2718,6 +2759,8 @@ int cpufreq_boost_trigger_state(int state) 
		ret = cpufreq_driver->set_boost(policy, state);

		if (ret)

			goto err_reset_state;



		policy->boost_enabled = state;

	}

	cpus_read_unlock();

include/linux/cpufreq.h

+3 −0
Original line number Diff line number Diff line
@@ -141,6 +141,9 @@ struct cpufreq_policy { 
	 */

	bool			dvfs_possible_from_any_cpu;



	/* Per policy boost enabled flag. */

	bool			boost_enabled;



	 /* Cached frequency lookup from cpufreq_driver_resolve_freq. */

	unsigned int cached_target_freq;

	unsigned int cached_resolved_idx;