Re: [RFC V5 02/16] blk/rq-qos: prepare to make blk-rq-qos pluggable

[Tejun Heo <tj@kernel.org>]

On Thu, Feb 24, 2022 at 05:06:40PM +0800, Wang Jianchao (Kuaishou) wrote:
> This patch makes blk-rq-qos policies pluggable as following,
> (1) Add code to maintain the rq_qos_ops. A rq-qos policy need to
>     register itself with rq_qos_register(). The original enum
>     rq_qos_id will be removed in following patch. They will use
>     a dynamic id maintained by rq_qos_ida.
> (2) Add .init callback into rq_qos_ops. We use it to initialize the
>     resource.
> (3) Add /sys/block/x/queue/qos
>     We can use '+name' or "-name" to open or close the blk-rq-qos
>     policy.
> 
> This patch mainly prepare help interfaces and no functional changes.
> Following patches will adpat the code of wbt, iolatency, iocost and
> ioprio to make them pluggable one by one. And after that, the sysfs
> interface /sys/block/xxx/queue/qos will be exported.
> 
> Signed-off-by: Wang Jianchao (Kuaishou) <jianchao.wan9@gmail.com>

As discussed before, the addition of new interface and custom module loading
mechanism is unnecessary and undesirable.

Nacked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun