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

Commit d4edd662 authored by Juri Lelli's avatar Juri Lelli Committed by Ingo Molnar
Browse files

sched/cpufreq: Use the DEADLINE utilization signal 



SCHED_DEADLINE tracks active utilization signal with a per dl_rq
variable named running_bw.

Make use of that to drive CPU frequency selection: add up FAIR and
DEADLINE contribution to get the required CPU capacity to handle both
requirements (while RT still selects max frequency).

Co-authored-by: default avatarClaudio Scordino <claudio@evidence.eu.com>
Signed-off-by: default avatarJuri Lelli <juri.lelli@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: alessio.balsini@arm.com
Cc: bristot@redhat.com
Cc: dietmar.eggemann@arm.com
Cc: joelaf@google.com
Cc: juri.lelli@redhat.com
Cc: mathieu.poirier@linaro.org
Cc: morten.rasmussen@arm.com
Cc: patrick.bellasi@arm.com
Cc: rjw@rjwysocki.net
Cc: rostedt@goodmis.org
Cc: tkjos@android.com
Cc: tommaso.cucinotta@santannapisa.it
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/20171204102325.5110-2-juri.lelli@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 34be3930

include/linux/sched/cpufreq.h

+0 −2
Original line number Diff line number Diff line
@@ -12,8 +12,6 @@ 
#define SCHED_CPUFREQ_DL	(1U << 1)

#define SCHED_CPUFREQ_IOWAIT	(1U << 2)



#define SCHED_CPUFREQ_RT_DL	(SCHED_CPUFREQ_RT | SCHED_CPUFREQ_DL)



#ifdef CONFIG_CPU_FREQ

struct update_util_data {

       void (*func)(struct update_util_data *data, u64 time, unsigned int flags);

kernel/sched/cpufreq_schedutil.c

+15 −10
Original line number Diff line number Diff line
@@ -179,12 +179,17 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, 
static void sugov_get_util(unsigned long *util, unsigned long *max, int cpu)

{

	struct rq *rq = cpu_rq(cpu);

	unsigned long cfs_max;

	unsigned long util_cfs = cpu_util_cfs(rq);

	unsigned long util_dl  = cpu_util_dl(rq);



	cfs_max = arch_scale_cpu_capacity(NULL, cpu);

	*max = arch_scale_cpu_capacity(NULL, cpu);



	*util = min(rq->cfs.avg.util_avg, cfs_max);

	*max = cfs_max;

	/*

	 * Ideally we would like to set util_dl as min/guaranteed freq and

	 * util_cfs + util_dl as requested freq. However, cpufreq is not yet

	 * ready for such an interface. So, we only do the latter for now.

	 */

	*util = min(util_cfs + util_dl, *max);

}



static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time)
@@ -271,7 +276,7 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, 


	busy = sugov_cpu_is_busy(sg_cpu);



	if (flags & SCHED_CPUFREQ_RT_DL) {

	if (flags & SCHED_CPUFREQ_RT) {

		next_f = policy->cpuinfo.max_freq;

	} else {

		sugov_get_util(&util, &max, sg_cpu->cpu);
@@ -316,7 +321,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) 
			j_sg_cpu->iowait_boost_pending = false;

			continue;

		}

		if (j_sg_cpu->flags & SCHED_CPUFREQ_RT_DL)

		if (j_sg_cpu->flags & SCHED_CPUFREQ_RT)

			return policy->cpuinfo.max_freq;



		j_util = j_sg_cpu->util;
@@ -352,7 +357,7 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time, 
	sg_cpu->last_update = time;



	if (sugov_should_update_freq(sg_policy, time)) {

		if (flags & SCHED_CPUFREQ_RT_DL)

		if (flags & SCHED_CPUFREQ_RT)

			next_f = sg_policy->policy->cpuinfo.max_freq;

		else

			next_f = sugov_next_freq_shared(sg_cpu, time);
@@ -382,9 +387,9 @@ static void sugov_irq_work(struct irq_work *irq_work) 
	sg_policy = container_of(irq_work, struct sugov_policy, irq_work);



	/*

	 * For RT and deadline tasks, the schedutil governor shoots the

	 * frequency to maximum. Special care must be taken to ensure that this

	 * kthread doesn't result in the same behavior.

	 * For RT tasks, the schedutil governor shoots the frequency to maximum.

	 * Special care must be taken to ensure that this kthread doesn't result

	 * in the same behavior.

	 *

	 * This is (mostly) guaranteed by the work_in_progress flag. The flag is

	 * updated only at the end of the sugov_work() function and before that

kernel/sched/sched.h

+10 −0
Original line number Diff line number Diff line
@@ -2084,3 +2084,13 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} 
#else /* arch_scale_freq_capacity */

#define arch_scale_freq_invariant()	(false)

#endif



static inline unsigned long cpu_util_dl(struct rq *rq)

{

	return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;

}



static inline unsigned long cpu_util_cfs(struct rq *rq)

{

	return rq->cfs.avg.util_avg;

}