Re: [RFC V4 1/6] blk: prepare to make blk-rq-qos pluggable and modular

[Wang Jianchao <jianchao.wan9@gmail.com>]

On 2022/2/23 11:08 上午, Wang Jianchao wrote:
> 
> 
> On 2022/2/23 1:19 上午, Tejun Heo wrote:
>> Hello,
>>
>> On Thu, Feb 17, 2022 at 11:13:44AM +0800, Wang Jianchao (Kuaishou) wrote:
>>> (3) Add /sys/block/x/queue/qos
>>>     We can use '+name' or "-name" to open or close the blk-rq-qos
>>>     policy.
>>
>> I don't understand why we're modularizing rq-qos in this non-standard way
>> instead of modprobing to enable a policy and rmmoding to disable. Why are we
>> building in qos names into the kernel and adding an extra module handling
>> interface?
> 
> Hi Tejun
> 
> We just want to provide the flexibility for the user to open/close a policy
> per device. If we need to the policy on a device, we needn't to waste cpu
sorry, it should be "If we don't need the policy on a device" ;)

Thanks
Jianchao
> cycles and memory for it.
> 
> Thanks
> Jianchao