linux-kernel - Re: [PATCH v1 3/5] cpuidle: governors: teo: Refine tick

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Message-ID: <f366937a-1748-4319-b545-48f3f2a728d7@arm.com>
Date: Wed, 21 Jan 2026 13:36:52 +0000
From: Christian Loehle <christian.loehle@....com>
To: "Rafael J. Wysocki" <rafael@...nel.org>,
 Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>, Doug Smythies <dsmythies@...us.net>
Subject: Re: [PATCH v1 3/5] cpuidle: governors: teo: Refine tick_intercepts vs
 total events check

On 1/14/26 19:45, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> Use 2/3 as the proportion coefficient in the check comparing
> cpu_data->tick_intercepts with cpu_data->total because it is close
> enough to the current one (5/8) and it allows of more straightforward
> interpretation (on average, intercepts within the tick period length
> are twice as frequent as other events).
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
>  drivers/cpuidle/governors/teo.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/drivers/cpuidle/governors/teo.c
> +++ b/drivers/cpuidle/governors/teo.c
> @@ -485,7 +485,7 @@ constraint:
>  	 * total wakeup events, do not stop the tick.
>  	 */
>  	if (drv->states[idx].target_residency_ns < TICK_NSEC &&
> -	    cpu_data->tick_intercepts > cpu_data->total / 2 + cpu_data->total / 8)
> +	    3 * cpu_data->tick_intercepts >= 2 * cpu_data->total)
>  		duration_ns = TICK_NSEC / 2;
>  

Sure, I guess the 2 and 8 was just as arbitrary to avoid a division.

Reviewed-by: Christian Loehle <christian.loehle@....com>