> On Jun 5, 2018, at 1:46 PM, Pete Heist <[email protected]> wrote: > >> On Jun 4, 2018, at 1:26 AM, Toke Høiland-Jørgensen <[email protected]> wrote: >> >> Georgios Amanakis <[email protected]> writes: >> >>> I am trying to reproduce this with veth to no avail. >>> I compiled a net-next kernel with Toke's configuration, and simplified >>> veth to only a client and a server. >> >> Hmm. Guess it may only be triggered by the way the mlx5 driver calls >> transmit, or something? Guess I'll have to go back and check once I get >> some spare cycles on that machine... > > As another test, I tried redirecting egress and ingress of the loopback > adapter through a common IFB. I couldn’t reproduce it either, but I can only > hit ~3Gbit total with cake and flent running on one APU2. > > If anyone wants to try it (faster hardware?), just run the attached > ‘flentlo.sh' with no arguments as root on a box with cake and flent installed > and netserver running. One run is done with noqueue and the other with cake > datacentre. > > Interestingly, for me the ‘datacentre' keyword actually both increases total > throughput and reduces rtt in this case (3286Mbit/5ms vs 2838Mbit/15ms), so I > left that in the test. I wonder if the rtt parameter affects the lockup in > any way, but I doubt it. > > Also, this is a case where using netperf UDP_RR reduces total throughput vs > irtt (for me, 2910Mbit vs 3286Mbit), probably due to competition.
Update attached just using lo on egress without IFB (also replacing ifconfig with ip). Tested on VMWare w/ Debian 9 unstable (kernel 4.16.0-2) up to 22Gbit and still didn’t see a lockup. This is as far as I can go with what I have available. George’s veth test is probably closer to the original config anyway.
flentlo.tgz
Description: Binary data
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