Re: [PATCH 8/8] hrtimer: Remove hrtimer_clock_base::get_time

[Peter Zijlstra <peterz@infradead.org>]

On Tue, Aug 12, 2025 at 08:08:16AM +0200, Thomas Weißschuh wrote:

> @@ -76,42 +77,34 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
>  		{
>  			.index = HRTIMER_BASE_MONOTONIC,
>  			.clockid = CLOCK_MONOTONIC,
> -			.get_time = &ktime_get,
>  		},
>  		{
>  			.index = HRTIMER_BASE_REALTIME,
>  			.clockid = CLOCK_REALTIME,
> -			.get_time = &ktime_get_real,
>  		},
>  		{
>  			.index = HRTIMER_BASE_BOOTTIME,
>  			.clockid = CLOCK_BOOTTIME,
> -			.get_time = &ktime_get_boottime,
>  		},
>  		{
>  			.index = HRTIMER_BASE_TAI,
>  			.clockid = CLOCK_TAI,
> -			.get_time = &ktime_get_clocktai,
>  		},
>  		{
>  			.index = HRTIMER_BASE_MONOTONIC_SOFT,
>  			.clockid = CLOCK_MONOTONIC,
> -			.get_time = &ktime_get,
>  		},
>  		{
>  			.index = HRTIMER_BASE_REALTIME_SOFT,
>  			.clockid = CLOCK_REALTIME,
> -			.get_time = &ktime_get_real,
>  		},
>  		{
>  			.index = HRTIMER_BASE_BOOTTIME_SOFT,
>  			.clockid = CLOCK_BOOTTIME,
> -			.get_time = &ktime_get_boottime,
>  		},
>  		{
>  			.index = HRTIMER_BASE_TAI_SOFT,
>  			.clockid = CLOCK_TAI,
> -			.get_time = &ktime_get_clocktai,
>  		},
>  	},
>  	.csd = CSD_INIT(retrigger_next_event, NULL)
> @@ -1253,7 +1246,7 @@ static int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
>  	remove_hrtimer(timer, base, true, force_local);
>  
>  	if (mode & HRTIMER_MODE_REL)
> -		tim = ktime_add_safe(tim, base->get_time());
> +		tim = ktime_add_safe(tim, __hrtimer_cb_get_time(base->clockid));
>  
>  	tim = hrtimer_update_lowres(timer, tim, mode);
>  
> @@ -1588,6 +1581,29 @@ static inline int hrtimer_clockid_to_base(clockid_t clock_id)
>  	}
>  }
>  
> +static ktime_t __hrtimer_cb_get_time(clockid_t clock_id)
> +{
> +	switch (clock_id) {
> +	case CLOCK_REALTIME:
> +		return ktime_get_real();
> +	case CLOCK_MONOTONIC:
> +		return ktime_get();
> +	case CLOCK_BOOTTIME:
> +		return ktime_get_boottime();
> +	case CLOCK_TAI:
> +		return ktime_get_clocktai();

It would've been nice if these had the same order as the other array.

> +	default:
> +		WARN(1, "Invalid clockid %d. Using MONOTONIC\n", clock_id);
> +		return ktime_get();
> +	}
> +}