[tip:sched/core] cpufreq: schedutil: fix equation in comment
From: tip-bot for Qais Yousef
Date: Thu Aug 08 2019 - 07:00:34 EST
Commit-ID: 5c3ceef9ad7b340b0acee6c26d0c9e6429decb2c
Gitweb: https://git.kernel.org/tip/5c3ceef9ad7b340b0acee6c26d0c9e6429decb2c
Author: Qais Yousef <qais.yousef@xxxxxxx>
AuthorDate: Fri, 2 Aug 2019 11:46:28 +0100
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitDate: Thu, 8 Aug 2019 09:09:31 +0200
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@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Acked-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "Rafael J . Wysocki" <rjw@xxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190802104628.8410-1-qais.yousef@xxxxxxx
---
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;