[PATCH] PM:EM: fix wrong utilization estimation in em_cpu_energy()

Vincent Guittot posted 1 patch 1 year, 10 months ago
include/linux/energy_model.h | 1 -
1 file changed, 1 deletion(-)
[PATCH] PM:EM: fix wrong utilization estimation in em_cpu_energy()
Posted by Vincent Guittot 1 year, 10 months ago
Commit 1b600da51073 ("PM: EM: Optimize em_cpu_energy() and remove division")
has added back map_util_perf() in em_cpu_energy() computation which has
been removed with the rework of scheduler/cpufreq interface.
This is wrong because sugov_effective_cpu_perf() already takes care of
mapping the utilization to a performance level.

Fixes: 1b600da51073 ("PM: EM: Optimize em_cpu_energy() and remove division")
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
---
 include/linux/energy_model.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
index 770755df852f..70cd7258cd29 100644
--- a/include/linux/energy_model.h
+++ b/include/linux/energy_model.h
@@ -245,7 +245,6 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
 	 * max utilization to the allowed CPU capacity before calculating
 	 * effective performance.
 	 */
-	max_util = map_util_perf(max_util);
 	max_util = min(max_util, allowed_cpu_cap);
 
 	/*
-- 
2.34.1
Re: [PATCH] PM:EM: fix wrong utilization estimation in em_cpu_energy()
Posted by Lukasz Luba 1 year, 10 months ago
Hi Vincent,

On 4/4/24 11:42, Vincent Guittot wrote:
> Commit 1b600da51073 ("PM: EM: Optimize em_cpu_energy() and remove division")
> has added back map_util_perf() in em_cpu_energy() computation which has
> been removed with the rework of scheduler/cpufreq interface.
> This is wrong because sugov_effective_cpu_perf() already takes care of
> mapping the utilization to a performance level.
> 
> Fixes: 1b600da51073 ("PM: EM: Optimize em_cpu_energy() and remove division")
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
>   include/linux/energy_model.h | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
> index 770755df852f..70cd7258cd29 100644
> --- a/include/linux/energy_model.h
> +++ b/include/linux/energy_model.h
> @@ -245,7 +245,6 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
>   	 * max utilization to the allowed CPU capacity before calculating
>   	 * effective performance.
>   	 */
> -	max_util = map_util_perf(max_util);
>   	max_util = min(max_util, allowed_cpu_cap);
>   
>   	/*

LGTM. It was developed in parallel IIRC and that change which removes
the extra margin to the util was lost from my radar. I can see it
landed first.

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

Regards,
Lukasz