linux-kernel - Re: [PATCH 2/6 v8] sched/fair: Update overutilized detection

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Message-ID: <20260206174223.qpx2tyfwoq5jkxde@airbuntu>
Date: Fri, 6 Feb 2026 17:42:23 +0000
From: Qais Yousef <qyousef@...alina.io>
To: Vincent Guittot <vincent.guittot@...aro.org>
Cc: mingo@...hat.com, peterz@...radead.org, juri.lelli@...hat.com,
	dietmar.eggemann@....com, rostedt@...dmis.org, bsegall@...gle.com,
	mgorman@...e.de, vschneid@...hat.com, linux-kernel@...r.kernel.org,
	pierre.gondois@....com, kprateek.nayak@....com,
	hongyan.xia2@....com, christian.loehle@....com,
	luis.machado@....com
Subject: Re: [PATCH 2/6 v8] sched/fair: Update overutilized detection

On 12/02/25 19:12, Vincent Guittot wrote:
> Checking uclamp_min is useless and counterproductive for overutilized state
> as misfit can now happen without being in overutilized state
> 
> Signed-off-by: Vincent Guittot <vincent.guittot@...aro.org>

Reviewed-by: Qais Yousef <qyousef@...alina.io>

> ---
>  kernel/sched/fair.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index b10f04715251..f430ec890b72 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6785,16 +6785,15 @@ static inline void hrtick_update(struct rq *rq)
>  
>  static inline bool cpu_overutilized(int cpu)
>  {
> -	unsigned long  rq_util_min, rq_util_max;
> +	unsigned long rq_util_max;
>  
>  	if (!sched_energy_enabled())
>  		return false;
>  
> -	rq_util_min = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MIN);
>  	rq_util_max = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MAX);
>  
>  	/* Return true only if the utilization doesn't fit CPU's capacity */
> -	return !util_fits_cpu(cpu_util_cfs(cpu), rq_util_min, rq_util_max, cpu);
> +	return !util_fits_cpu(cpu_util_cfs(cpu), 0, rq_util_max, cpu);
>  }
>  
>  /*
> -- 
> 2.43.0
>