I brought up on the -transport call last week that I was having trouble receiving 8KB packets at 40Gbps. I blamed "TCP stack" peformance, although what I really meant was "kernel performance" -- I just assumed that the problem was in the stack. From looking at a flamegraph, I'm not so sure this was the case. The flamegraph was taken on a "FreeBSD 10.1-ish" system. Unfortunately running stock FreeBSD head in this environment is quite difficult, so I probably wouldn't be able to check if anything on head has alleviated things. You can see the flamegraph for youself here:
https://people.freebsd.org/~rstone/incast_8kb_flame.svg You'll note that my underland application is way off in the bottom left, taking 3% of all cycles. Meanwhile top reports that the system is completely bogged down in interrupt and system time. _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-transport To unsubscribe, send any mail to "[email protected]"
