On Sat, 2022-02-19 at 17:22 -0700, Jens Axboe wrote: > > Outside of this, I was hoping to see some performance numbers in the > main patch. Sounds like you have them, can you share? > Yes. It is not much. Only numbers from my application and it is far from being the best benchmark because the result can be influenced by multiple external factors. Beside addressing the race condition remaining inside io_cqring_wait() around napi_list for v2 patch, creating a benchmark program that isolate the performance of the new feature is on my todo list. I would think that creating a simple UDP ping-pong setup and measure RTT with and without busy_polling should be a good enough test. In the meantime, here are the results that I have: Without io_uring busy poll: reaction time to an update: 17159usec reaction time to an update: 19068usec reaction time to an update: 23055usec reaction time to an update: 16511usec reaction time to an update: 17604usec With io_uring busy poll: reaction time to an update: 15782usec reaction time to an update: 15337usec reaction time to an update: 15379usec reaction time to an update: 15275usec reaction time to an update: 15107usec Concerning my latency issue with busy polling, I have found this that might help me: https://lwn.net/ml/netdev/20201002222514.1159492-1-weiwan@xxxxxxxxxx/
