Re: [PATCH v4 01/19] ioprio: cleanup interface definition

[Bart Van Assche <bvanassche@xxxxxxx>]

On 3/9/23 13:54, Niklas Cassel wrote:
>   /*
> - * The RT and BE priority classes both support up to 8 priority levels.
> + * The RT and BE priority classes both support up to 8 priority levels that
> + * can be specified using the lower 3-bits of the priority data.
>    */
> -#define IOPRIO_NR_LEVELS	8
> -#define IOPRIO_BE_NR		IOPRIO_NR_LEVELS
> +#define IOPRIO_LEVEL_NR_BITS		3
> +#define IOPRIO_NR_LEVELS		(1 << IOPRIO_LEVEL_NR_BITS)
> +#define IOPRIO_LEVEL_MASK		(IOPRIO_NR_LEVELS - 1)
> +#define IOPRIO_PRIO_LEVEL(ioprio)	((ioprio) & IOPRIO_LEVEL_MASK)
>   
> +#define IOPRIO_BE_NR			IOPRIO_NR_LEVELS

Is my understanding correct that today four I/O priority levels are 
supported and that these occupy two bits?

Thanks,

Bart.