* [PATCH] cpufreq: schedutil: fix equation in comment
@ 2019-08-02 10:46 Qais Yousef
2019-08-02 13:19 ` Vincent Guittot
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Qais Yousef @ 2019-08-02 10:46 UTC (permalink / raw)
To: Peter Zijlstra, Rafael J . Wysocki
Cc: Viresh Kumar, Ingo Molnar, linux-pm, linux-kernel, Qais Yousef
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>
---
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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] cpufreq: schedutil: fix equation in comment
2019-08-02 10:46 [PATCH] cpufreq: schedutil: fix equation in comment Qais Yousef
@ 2019-08-02 13:19 ` Vincent Guittot
2019-08-05 4:54 ` Viresh Kumar
2019-08-05 13:06 ` Peter Zijlstra
2 siblings, 0 replies; 6+ messages in thread
From: Vincent Guittot @ 2019-08-02 13:19 UTC (permalink / raw)
To: Qais Yousef
Cc: Peter Zijlstra, Rafael J . Wysocki, Viresh Kumar, Ingo Molnar,
open list:THERMAL, linux-kernel
On Fri, 2 Aug 2019 at 12:46, Qais Yousef <qais.yousef@arm.com> wrote:
>
> 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>
FWIW
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
> 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
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cpufreq: schedutil: fix equation in comment
2019-08-02 10:46 [PATCH] cpufreq: schedutil: fix equation in comment Qais Yousef
2019-08-02 13:19 ` Vincent Guittot
@ 2019-08-05 4:54 ` Viresh Kumar
2019-08-05 13:06 ` Peter Zijlstra
2 siblings, 0 replies; 6+ messages in thread
From: Viresh Kumar @ 2019-08-05 4:54 UTC (permalink / raw)
To: Qais Yousef
Cc: Peter Zijlstra, Rafael J . Wysocki, Ingo Molnar, linux-pm, linux-kernel
On 02-08-19, 11:46, Qais Yousef wrote:
> 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>
> ---
> 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;
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
--
viresh
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cpufreq: schedutil: fix equation in comment
2019-08-02 10:46 [PATCH] cpufreq: schedutil: fix equation in comment Qais Yousef
2019-08-02 13:19 ` Vincent Guittot
2019-08-05 4:54 ` Viresh Kumar
@ 2019-08-05 13:06 ` Peter Zijlstra
2019-08-07 9:42 ` Rafael J. Wysocki
2 siblings, 1 reply; 6+ messages in thread
From: Peter Zijlstra @ 2019-08-05 13:06 UTC (permalink / raw)
To: Qais Yousef
Cc: Rafael J . Wysocki, Viresh Kumar, Ingo Molnar, linux-pm, linux-kernel
On Fri, Aug 02, 2019 at 11:46:28AM +0100, Qais Yousef wrote:
> 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>
Thanks!
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cpufreq: schedutil: fix equation in comment
2019-08-05 13:06 ` Peter Zijlstra
@ 2019-08-07 9:42 ` Rafael J. Wysocki
2019-08-08 11:44 ` Qais Yousef
0 siblings, 1 reply; 6+ messages in thread
From: Rafael J. Wysocki @ 2019-08-07 9:42 UTC (permalink / raw)
To: Peter Zijlstra
Cc: Qais Yousef, Viresh Kumar, Ingo Molnar, linux-pm, linux-kernel
On Monday, August 5, 2019 3:06:20 PM CEST Peter Zijlstra wrote:
> On Fri, Aug 02, 2019 at 11:46:28AM +0100, Qais Yousef wrote:
> > 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>
>
> Thanks!
>
I've applied this, so please let me know if it has gone into -tip too and I'll drop it then.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] cpufreq: schedutil: fix equation in comment
2019-08-07 9:42 ` Rafael J. Wysocki
@ 2019-08-08 11:44 ` Qais Yousef
0 siblings, 0 replies; 6+ messages in thread
From: Qais Yousef @ 2019-08-08 11:44 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Peter Zijlstra, Viresh Kumar, Ingo Molnar, linux-pm, linux-kernel
On 08/07/19 11:42, Rafael J. Wysocki wrote:
> On Monday, August 5, 2019 3:06:20 PM CEST Peter Zijlstra wrote:
> > On Fri, Aug 02, 2019 at 11:46:28AM +0100, Qais Yousef wrote:
> > > 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>
> >
> > Thanks!
> >
>
> I've applied this, so please let me know if it has gone into -tip too and I'll drop it then.
FYI I've just got an email from tip-bot that it was committed there.
Thanks!
--
Qais Yousef
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-08-08 11:44 UTC | newest]
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2019-08-02 10:46 [PATCH] cpufreq: schedutil: fix equation in comment Qais Yousef
2019-08-02 13:19 ` Vincent Guittot
2019-08-05 4:54 ` Viresh Kumar
2019-08-05 13:06 ` Peter Zijlstra
2019-08-07 9:42 ` Rafael J. Wysocki
2019-08-08 11:44 ` Qais Yousef
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