Re: [PATCH v8 09/25] timer: Split out get next timer functionality

[Thomas Gleixner]

On Wed, Oct 04 2023 at 14:34, Anna-Maria Behnsen wrote:
> Split out get next timer functionality to make it reusable in other
> places. Thereby the order of getting the next expiry, forwarding the base
> clock and mark timer bases as idle, is changed. This change of order
> shouldn't have any impact, as nothing inside the function relies on the
> idle value or the updated timer base clock.

This interestingly corrects the issue of patch 8/25 because

> +	nextevt = __get_next_timer_interrupt(basej, base);
>  
>  	/*
>  	 * We have a fresh next event. Check whether we can forward the
> @@ -1952,14 +1968,10 @@ u64 get_next_timer_interrupt(unsigned long basej, u64 basem)
>  	 */
>  	base->is_idle = time_after(nextevt, basej + 1);

base->is_idle is now handled in the correct order vs. the nextevt evaluation.
  
> -	if (base->timers_pending) {
> -		/* If we missed a tick already, force 0 delta */
> -		if (time_before(nextevt, basej))
> -			nextevt = basej;
> -		expires = basem + (u64)(nextevt - basej) * TICK_NSEC;
> -	}
>  	raw_spin_unlock(&base->lock);

Thanks,

        tglx