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Subject[tip:sched/core] cpufreq: schedutil: fix equation in comment
Commit-ID:  5c3ceef9ad7b340b0acee6c26d0c9e6429decb2c
Gitweb: https://git.kernel.org/tip/5c3ceef9ad7b340b0acee6c26d0c9e6429decb2c
Author: Qais Yousef <qais.yousef@arm.com>
AuthorDate: Fri, 2 Aug 2019 11:46:28 +0100
Committer: Peter Zijlstra <peterz@infradead.org>
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@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net>
Link: https://lkml.kernel.org/r/20190802104628.8410-1-qais.yousef@arm.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;
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