On Sun, 2016-10-09 at 19:48 +0000, Chopra, Manish wrote: > Hi Eric, I used "-n" as well with "-N" but still the problem doesn't > go away. > > This is what I have done - > > Started "netserver" on local/test setup > > #netserver > Starting netserver with host 'IN(6)ADDR_ANY' port '12865' and family > AF_UNSPEC > > It starts listening on port "12865" > > From remote setup, started multiple netperf using different ports for > data sockets specified using "-P" with "-N" and "-n" options specified > as well. > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 8,8 -- -N -n -m 1400 > -P 6660,5550 & > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 9,9 -- -N -n -m 1400 > -P 9990,9880 & > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 10,10 -- -N -n -m > 1400 -P 4455,4400 & > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 11,11 -- -N -n -m > 1400 -P 3300,7800 & > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 12,12 -- -N -n -m > 1400 -P 50512,44444 & > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 13,13 -- -N -n -m > 1400 -P 10512,45672 & > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 14,14 -- -N -n -m > 1400 -P 8888,56721 & > netperf -H 192.168.200.40 -l 150 -t UDP_STREAM -T 15,15 -- -N -n -m > 1400 -P 9300,8899 & > > When on local/test receiving setup, I dump skb's IP header protocol > field in .ndo_rx_flow_steer() handler - it is still always > IPPROTO_TCP. > Which has destined port 12865. But that handler never receives a SKB > whose IP header protocol field is set to IPPROTO_UDP. > > As suspected, I believe in receive flow, packets always go in the path > where it never match any entry in global flow table in get_rps_cpu() > function > ,possibly due to packets don't get received from the flow of > inet_recvmsg() which updates the global flow table ? > > 3571 /* First check into global flow table if there is > a match */ > 3572 ident = sock_flow_table->ents[hash & > sock_flow_table->mask]; > 3573 if ((ident ^ hash) & ~rps_cpu_mask) > 3574 goto try_rps; > > Hence, it never call set_rps_cpu() which internally is supposed to > call .ndo_rx_flow_steer() for the SKB's whose flows to be steered. > > On another side, when I use "Iperf" for sending UDP stream, which I > believe receives the packets from the intet_recvmsg() flow > and I do see flows getting steered for UDP packets. [Actually seeing > SKB's whose IP header protocol set to IPPROTO_UDP arriving > in .ndo-rx_flow_steer()]. > > iperf -s -u > iperf -u -c 192.168.200.40 -t 3000 -i 10 -P 8
OK, I am adding/CC Rick Jones, netperf author, since it seems a netperf bug, not a kernel one. I believe I already mentioned fact that "UDP_STREAM -- -N" was not doing a connect() on the receiver side. > > >
