From: Dietmar Eggemann <dietmar.eggemann@arm.com>
Date: Tue, 27 Jan 2015 14:04:17 +0000 (+0000)
Subject: sched: Determine the current sched_group idle-state
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ec055b978e851118a2b9d42f61ecad619cd1ce77;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

sched: Determine the current sched_group idle-state

To estimate the energy consumption of a sched_group in
sched_group_energy() it is necessary to know which idle-state the group
is in when it is idle. For now, it is assumed that this is the current
idle-state (though it might be wrong). Based on the individual cpu
idle-states group_idle_state() finds the group idle-state.

cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
---

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3cfb4be3d88f..c11bc7392916 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4815,6 +4815,20 @@ static int find_new_capacity(struct energy_env *eenv,
 	return idx;
 }
 
+static int group_idle_state(struct sched_group *sg)
+{
+	int i, state = INT_MAX;
+
+	/* Find the shallowest idle state in the sched group. */
+	for_each_cpu(i, sched_group_cpus(sg))
+		state = min(state, idle_get_state_idx(cpu_rq(i)));
+
+	/* Take non-cpuidle idling into account (active idle/arch_cpu_idle()) */
+	state++;
+
+	return state;
+}
+
 /*
  * sched_group_energy(): Computes the absolute energy consumption of cpus
  * belonging to the sched_group including shared resources shared only by
@@ -4867,7 +4881,8 @@ static int sched_group_energy(struct energy_env *eenv)
 
 			do {
 				unsigned long group_util;
-				int sg_busy_energy, sg_idle_energy, cap_idx;
+				int sg_busy_energy, sg_idle_energy;
+				int cap_idx, idle_idx;
 
 				if (sg_shared_cap && sg_shared_cap->group_weight >= sg->group_weight)
 					eenv->sg_cap = sg_shared_cap;
@@ -4875,11 +4890,13 @@ static int sched_group_energy(struct energy_env *eenv)
 					eenv->sg_cap = sg;
 
 				cap_idx = find_new_capacity(eenv, sg->sge);
+				idle_idx = group_idle_state(sg);
 				group_util = group_norm_util(eenv, sg);
 				sg_busy_energy = (group_util * sg->sge->cap_states[cap_idx].power)
-										>> SCHED_CAPACITY_SHIFT;
-				sg_idle_energy = ((SCHED_LOAD_SCALE-group_util) * sg->sge->idle_states[0].power)
-										>> SCHED_CAPACITY_SHIFT;
+								>> SCHED_CAPACITY_SHIFT;
+				sg_idle_energy = ((SCHED_LOAD_SCALE-group_util)
+								* sg->sge->idle_states[idle_idx].power)
+								>> SCHED_CAPACITY_SHIFT;
 
 				total_energy += sg_busy_energy + sg_idle_energy;