On 4/19/22 5:07 AM, Avi Kivity wrote: > A simple webserver shows about 5% loss compared to linux-aio. > > > I expect the loss is due to an optimization that io_uring lacks - > inline completion vs workqueue completion: I don't think that's it, io_uring never punts to a workqueue for completions. The aio inline completions is more of a hack because it needs to do that, as always using a workqueue would lead to bad performance and higher overhead. So if there's a difference in performance, it's something else and we need to look at that. But your report is pretty lacking! What kernel are you running? Do you have a test case of sorts? For a performance oriented network setup, I'd normally not consider data readiness poll replacements to be that interesting, my recommendation would be to use async send/recv for that instead. That's how io_uring is supposed to be used, in a completion based model. -- Jens Axboe
