Re: [PATCH 2/2] ufs: don't use the fair tag sharings

From: Bart Van Assche
Date: Wed May 17 2023 - 14:23:35 EST


On 5/17/23 00:49, Yu Kuai wrote:
在 2023/05/16 23:12, Bart Van Assche 写道:
I propose that we switch to one of these two approaches:

How about a smoothing method that the device with more io will share
more tag, and each device will get at least one tag?

Hi Yu,

hctx_may_queue() is called from the hot path (blk_mq_get_tag()). I'm pretty sure that adding any nontrivial code in that path will cause a performance (IOPS) regression. So I don't think that adding a smoothing method in hctx_may_queue() is a realistic option.

Thanks,

Bart.