linux-kernel - [PATCH] cpufreq: schedutil: fix equation in comment

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Message-Id: <20190802104628.8410-1-qais.yousef@arm.com>
Date:   Fri,  2 Aug 2019 11:46:28 +0100
From:   Qais Yousef <qais.yousef@....com>
To:     Peter Zijlstra <peterz@...radead.org>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>
Cc:     Viresh Kumar <viresh.kumar@...aro.org>,
        Ingo Molnar <mingo@...hat.com>, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Qais Yousef <qais.yousef@....com>
Subject: [PATCH] cpufreq: schedutil: fix equation in comment

scale_irq_capacity() call in schedutil_cpu_util() does

	util *= (max - irq)
	util /= max

But the comment says

	util *= (1 - irq)
	util /= max

Fix the comment to match what the scaling function does.

Signed-off-by: Qais Yousef <qais.yousef@....com>
---
 kernel/sched/cpufreq_schedutil.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 636ca6f88c8e..e127d89d5974 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -259,9 +259,9 @@ unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
 	 * irq metric. Because IRQ/steal time is hidden from the task clock we
 	 * need to scale the task numbers:
 	 *
-	 *              1 - irq
-	 *   U' = irq + ------- * U
-	 *                max
+	 *              max - irq
+	 *   U' = irq + --------- * U
+	 *                 max
 	 */
 	util = scale_irq_capacity(util, irq, max);
 	util += irq;
-- 
2.17.1