On 10/9/24 10:35 AM, David Ahern wrote: > On 10/9/24 9:43 AM, Jens Axboe wrote: >> Yep basically line rate, I get 97-98Gbps. I originally used a slower box >> as the sender, but then you're capped on the non-zc sender being too >> slow. The intel box does better, but it's still basically maxing out the >> sender at this point. So yeah, with a faster (or more efficient sender), > > I am surprised by this comment. You should not see a Tx limited test > (including CPU bound sender). Tx with ZC has been the easy option for a > while now. I just set this up to test yesterday and just used default! I'm sure there is a zc option, just not the default and hence it wasn't used. I'll give it a spin, will be useful for 200G testing. >> I have no doubts this will go much higher per thread, if the link bw was >> there. When I looked at CPU usage for the receiver, the thread itself is >> using ~30% CPU. And then there's some softirq/irq time outside of that, >> but that should ammortize with higher bps rates too I'd expect. >> >> My nic does have 2 100G ports, so might warrant a bit more testing... >> > > It would be good to see what the next bottleneck is for io_uring with ZC > Rx path. My expectation is that a 200G link is a means to show you (ie., > you will not hit 200G so cpu monitoring, perf-top, etc will show the > limiter). I'm pretty familiar with profiling ;-) I'll see if I can get the 200G test setup and then I'll report back what I get. -- Jens Axboe