On 3/26/24 3:39, Jens Axboe wrote: >On 3/25/24 9:23 PM, Xue wrote: >> Hi, >> >> I hope this message finds you well. >> >> I'm waiting to follow up on the patch I submitted on 3.18, >> titled "io_uring: releasing CPU resources when polling". >> >> I haven't received feedback yet and wondering if you had >> a chance to look at it. Any guidance or suggestions you could >> provide would be greatly appreciated. > >I did take a look at it, and I have to be honest - I don't like it at >all. It's a lot of expensive code in the fast path, for a problem that >should not really exist. The system is misconfigured if you're doing >polled IO for devices that don't have a poll queue. At some point the >block layer returned -EOPNOTSUPP for that, and honestly I think that's a >MUCH better solution than adding expensive code in the fast path for >something that is really a badly configured setup. Sorry for my late reply, if you think that the scenario where if you're doing polled IO for devices that don't have a poll queue is just a misconfigured and does not need to be changed too much, then I'm inclined to extend this scenario to all devices, I think it's an effective way to release CPU resources, and I verified this and found that it does have a very good benefit. At the same time I have reduce the code in the fast path. I will release the v2 version of the code with my test results, and please reconsider the feasibility of this solution. -- Xue
