Re: [PATCH v7 1/9] blk-throttle: fix that io throttle can only work for single bio

From: Tejun Heo
Date: Mon Aug 22 2022 - 03:26:12 EST


Hello,

On Mon, Aug 22, 2022 at 11:06:44AM +0800, Yu Kuai wrote:
> While implementing the new method, I found that there seems to be a
> misunderstanding here, the code seems to try to add flag to split bio
> so that it won't be throttled again for bps limit, however:
>
> 1) for blk throttle, split bio is issued directly and will never be
> throttled again, while orignal bio will go through throttle path again.
> 2) if cloned bio is directed to a new disk, the flag is cleared anyway.

Doesn't that make the current code correct then? But you were seeing
incorrect behaviors, right?

Thanks.

--
tejun