Re: [PATCH v8 1/4] blk-throttle: fix that io throttle can only work for single bio

From: Yu Kuai
Date: Thu Aug 25 2022 - 21:07:36 EST


Hi, Tejun

在 2022/08/26 2:15, Tejun Heo 写道:
On Wed, Aug 24, 2022 at 09:15:32AM +0800, Yu Kuai wrote:
This patch actually set two flags when bio is throttled and
dispatched, and only iops flag is cleared after the original bio is
split. If only one flag can be used, the way that I come up with is
that let iops limit become default, which means bio is always counted
for iops limit each time blk_throtl_bio() is called. I'm not quite
sure yet if iops limit can be counted excessively this way in some
special scenario...

I don't think we have a path where we clone and re-submit other than
splitting. What do you think about renaming the flag to BIO_BPS_THROTTLED
and just assuming that IOPS is always applied?

Yes, I didn't found such path myself, this way sounds good. I'll send a
new version soon.

Thanks,
Kuai

Thanks.