linux-kernel - [RFCv3 PATCH 17/48] sched: Get rid of scaling usage by cpu_capacity

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Message-Id: <1423074685-6336-18-git-send-email-morten.rasmussen@arm.com>
Date:	Wed,  4 Feb 2015 18:30:54 +0000
From:	Morten Rasmussen <morten.rasmussen@....com>
To:	peterz@...radead.org, mingo@...hat.com
Cc:	vincent.guittot@...aro.org, dietmar.eggemann@....com,
	yuyang.du@...el.com, preeti@...ux.vnet.ibm.com,
	mturquette@...aro.org, nico@...aro.org, rjw@...ysocki.net,
	juri.lelli@....com, linux-kernel@...r.kernel.org
Subject: [RFCv3 PATCH 17/48] sched: Get rid of scaling usage by cpu_capacity_orig

From: Dietmar Eggemann <dietmar.eggemann@....com>

Since now we have besides frequency invariant also cpu (uarch plus max
system frequency) invariant cfs_rq::utilization_load_avg both, frequency
and cpu scaling happens as part of the load tracking.
So cfs_rq::utilization_load_avg does not have to be scaled by the original
capacity of the cpu again.

Cc: Ingo Molnar <mingo@...hat.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@....com>
---
 kernel/sched/fair.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 5375ab1..a85c34b 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4807,12 +4807,11 @@ static int select_idle_sibling(struct task_struct *p, int target)
 static int get_cpu_usage(int cpu)
 {
 	unsigned long usage = cpu_rq(cpu)->cfs.utilization_load_avg;
-	unsigned long capacity = capacity_orig_of(cpu);
 
 	if (usage >= SCHED_LOAD_SCALE)
-		return capacity;
+		return capacity_orig_of(cpu);
 
-	return (usage * capacity) >> SCHED_LOAD_SHIFT;
+	return usage;
 }
 
 /*
-- 
1.9.1

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