Messages in this thread | | | Date | Fri, 25 Feb 2022 10:11:29 +0800 | Subject | Re: [RFC V5 01/16] blk: make the whole blk_mq_submit_bio under q_usage_counter | From | Wang Jianchao <> |
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On 2022/2/24 9:38 下午, Christoph Hellwig wrote: > On Thu, Feb 24, 2022 at 05:06:39PM +0800, Wang Jianchao (Kuaishou) wrote: >> This is to protect the rqos list against the rqos open/close. We >> need to drain all of the caller of blk_mq_submit_bio() before >> we can operate the rqos list. > > This means ever I/O now has to d an extra refcount roundtrip.
If we want to save cpu cycles for the very fast device, why not introduce another blk_mq_submit_bio_fast() which can reduce the code drastically.
Thanks Jianchao
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