On 02/16/18 18:25, Oleksandr Natalenko wrote: > So, going on with two real HW hosts. They are both running latest stock Arch > Linux kernel (4.15.3-1-ARCH, CONFIG_PREEMPT=y, CONFIG_HZ=1000) and are > interconnected with 1 Gbps link (via switch if that matters). Using iperf3, > running each test for 20 seconds. > > Having BBR+fq_codel (or pfifo_fast, same result) on both hosts: > > Client to server: 112 Mbits/sec > Server to client: 96.1 Mbits/sec > > Having BBR+fq on both hosts: > > Client to server: 347 Mbits/sec > Server to client: 397 Mbits/sec > > Having YeAH+fq on both hosts: > > Client to server: 928 Mbits/sec > Server to client: 711 Mbits/sec > > (when the server generates traffic, the throughput is a little bit lower, as > you can see, but I assume that's because I have there low-power Silvermont > CPU, when the client has Ivy Bridge beast)
There is simply no reason why you shouldn't get approx. line rate (~920+-ish) Mbit over wired 1GBit Ethernet; even my broken 10-year old Core2Duo laptop can do that. Can you boot with spectre_v2=off and try "the simplest case" with the defaults cubic/pfifo_fast? spectre_v2 has terrible performance impact esp. on small/older processors. When I last benchmarked full PREEMPT with 4.9.x it was similarly bad and also had a noticeable network throughput impact even on my i7. Also congratulations for being the only other person I know who ever tried YeAH. :-) cheers Holger