linux-kernel - [PATCH V2 2/3] sched/fair: update cpu_capcity to reflect thermal pressure

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Date:   Tue, 16 Apr 2019 15:38:40 -0400
From:   Thara Gopinath <thara.gopinath@...aro.org>
To:     mingo@...hat.com, peterz@...radead.org, rui.zhang@...el.com
Cc:     linux-kernel@...r.kernel.org, amit.kachhap@...il.com,
        viresh.kumar@...aro.org, javi.merino@...nel.org,
        edubezval@...il.com, daniel.lezcano@...aro.org,
        vincent.guittot@...aro.org, nicolas.dechesne@...aro.org,
        bjorn.andersson@...aro.org, dietmar.eggemann@....com
Subject: [PATCH V2 2/3] sched/fair: update cpu_capcity to reflect thermal pressure

cpu_capacity relflects the maximum available capacity of a cpu. Thermal
pressure on a cpu means this maximum available capacity is reduced. This
patch reduces the average thermal pressure for a cpu from its maximum
available capacity so that cpu_capacity reflects the actual
available capacity.

Signed-off-by: Thara Gopinath <thara.gopinath@...aro.org>
---
 kernel/sched/fair.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8213ff6..c5454d3 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -23,6 +23,7 @@
 #include "sched.h"
 
 #include <trace/events/sched.h>
+#include <linux/sched/thermal.h>
 
 /*
  * Targeted preemption latency for CPU-bound tasks:
@@ -7967,6 +7968,9 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu)
 	if (!capacity)
 		capacity = 1;
 
+	capacity *= sched_get_thermal_pressure(cpu);
+	capacity >>= SCHED_CAPACITY_SHIFT;
+
 	cpu_rq(cpu)->cpu_capacity = capacity;
 	sdg->sgc->capacity = capacity;
 	sdg->sgc->min_capacity = capacity;
-- 
2.1.4