summaryrefslogtreecommitdiffstats
path: root/meta-eas/recipes-kernel/linux/linux-renesas/0046-sched-Make-energy-awareness-a-sched-feature.patch
blob: 9b9929b4e68acd0e4f69b74c7337eec5d74d4d23 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
From ac91525a35e79b82a09fb1ed75ee547802f3bed1 Mon Sep 17 00:00:00 2001
From: Morten Rasmussen <morten.rasmussen@arm.com>
Date: Tue, 13 Jan 2015 13:45:51 +0000
Subject: [PATCH 46/92] sched: Make energy awareness a sched feature

This patch introduces the ENERGY_AWARE sched feature, which is
implemented using jump labels when SCHED_DEBUG is defined. It is
statically set false when SCHED_DEBUG is not defined. Hence this doesn't
allow energy awareness to be enabled without SCHED_DEBUG. This
sched_feature knob will be replaced later with a more appropriate
control knob when things have matured a bit.

ENERGY_AWARE is based on per-entity load-tracking hence FAIR_GROUP_SCHED
must be enable. This dependency isn't checked at compile time yet.

cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
(cherry picked from commit e3b80d193dad157c720ec29496104126dbfc67ce)
Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
---
 kernel/sched/fair.c     | 5 +++++
 kernel/sched/features.h | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index cb283ca..fa393d9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5291,6 +5291,11 @@ static void record_wakee(struct task_struct *p)
 	}
 }
 
+static inline bool energy_aware(void)
+{
+	return sched_feat(ENERGY_AWARE);
+}
+
 /*
  * Detect M:N waker/wakee relationships via a switching-frequency heuristic.
  *
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 69631fa..b634151 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -69,3 +69,8 @@
 SCHED_FEAT(LB_MIN, false)
 SCHED_FEAT(ATTACH_AGE_LOAD, true)
 
+/*
+ * Energy aware scheduling. Use platform energy model to guide scheduling
+ * decisions optimizing for energy efficiency.
+ */
+SCHED_FEAT(ENERGY_AWARE, false)
-- 
1.9.1