[PATCH 04/16] md: add queue limit helpers

[Yu Kuai]

Hi,

在 2024/02/27 22:36, Christoph Hellwig 写道:
> On Mon, Feb 26, 2024 at 07:38:17PM +0800, Yu Kuai wrote:
>> Any reason to use blk_mq_freeze/unfreeze_queue ? I don't think this is
>> meaningful for raid, this only wait for IO submission, not IO done.
>>
>> raid should already handle concurrent IO with reshape, so I think this
>> can just be removed.
> 
> We can't just change limits under the driver if I/Os are being sumitted.
> That is one of the points of the whole queue limits exercises.
> 

Agree with this, it's just these apis can't gurantee this in raid, there
could still be IO inflight, perhaps you can use:

mddev_suspend(mddev)
...
mddev_resume(mddev)

Thanks,
Kuai

> .
>