Re: [PATCH v1 3/9] cpuidle: teo: Combine candidate state index checks against 0

From: Christian Loehle
Date: Wed Jan 15 2025 - 14:44:53 EST


On 1/13/25 18:39, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> There are two candidate state index checks against 0 in teo_select()
> that need not be separate, so combine them and update comments around
> them.
>
> No intentional functional impact.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> ---
>
> This is a rebased variant of
>
> https://lore.kernel.org/linux-pm/2296767.iZASKD2KPV@xxxxxxxxxxxxx/
>
> ---
> drivers/cpuidle/governors/teo.c | 23 +++++++++--------------
> 1 file changed, 9 insertions(+), 14 deletions(-)
>
> --- a/drivers/cpuidle/governors/teo.c
> +++ b/drivers/cpuidle/governors/teo.c
> @@ -436,24 +436,19 @@
> if (idx > constraint_idx)
> idx = constraint_idx;
>
> - if (!idx && prev_intercept_idx) {
> - /*
> - * We have to query the sleep length here otherwise we don't
> - * know after wakeup if our guess was correct.
> - */
> - duration_ns = tick_nohz_get_sleep_length(&delta_tick);
> - cpu_data->sleep_length_ns = duration_ns;
> + if (!idx) {
> + if (prev_intercept_idx) {
> + /*
> + * Query the sleep length to be able to count the wakeup
> + * as a hit if it is caused by a timer.
> + */
> + duration_ns = tick_nohz_get_sleep_length(&delta_tick);
> + cpu_data->sleep_length_ns = duration_ns;
> + }
> goto out_tick;
> }
>
> /*
> - * Skip the timers check if state 0 is the current candidate one,
> - * because an immediate non-timer wakeup is expected in that case.
> - */
> - if (!idx)
> - goto out_tick;
> -
> - /*
> * If state 0 is a polling one, check if the target residency of
> * the current candidate state is low enough and skip the timers
> * check in that case too.
>
>
>

This patch relies on the previous one, but given that you'll probably
convince me on that:
Reviewed-by: Christian Loehle <christian.loehle@xxxxxxx>