Re: [PATCH] Documentation: block: ioprio: Update schedulers

From: Johannes Thumshirn
Date: Wed Jan 17 2024 - 07:50:07 EST


On 17.01.24 13:20, Christian Loehle wrote:
> This doc hasn't been touched in a while, in the meantime some
> new io schedulers were added (e.g. all of mq), some with ioprio
> support.
>
> Signed-off-by: Christian Loehle <christian.loehle@xxxxxxx>
> ---
> Documentation/block/ioprio.rst | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/block/ioprio.rst b/Documentation/block/ioprio.rst
> index a25c6d5df87b..5410308888d2 100644
> --- a/Documentation/block/ioprio.rst
> +++ b/Documentation/block/ioprio.rst
> @@ -9,14 +9,14 @@ Intro
> With the introduction of cfq v3 (aka cfq-ts or time sliced cfq), basic io
> priorities are supported for reads on files. This enables users to io nice
> processes or process groups, similar to what has been possible with cpu
> -scheduling for ages. This document mainly details the current possibilities
> -with cfq; other io schedulers do not support io priorities thus far.
> +scheduling for ages. Support for io priorities is io scheduler dependent and
> +currently supported by bfq, mq-deadline and cfq.

CFQ went away with blk-mq and got replaced by BFQ IIRC.


>
> Scheduling classes
> ------------------
>
> -CFQ implements three generic scheduling classes that determine how io is
> -served for a process.
> +Three generic scheduling classes are implemented for io priorities that
> +determine how io is served for a process.
>
> IOPRIO_CLASS_RT: This is the realtime io class. This scheduling class is given
> higher priority than any other in the system, processes from this class are