On Fri, 2014-03-21 at 09:15 +0100, renaud sallantin wrote: > > FQ/pacing enables to do a lot of things, > and as I already said, it could be used to easily implement the > Initial Spreading. > (we did it and it' s just a few lines to add, and a couple of > parameters to change) > > > But for the moment, FQ/Pacing sends the IW in one burst (up to 10 > segments). >
This is not true. This depends on RTT and your qdisc parameters. Whole point of TSO autosizing is to make all this stuff automatic. Here is the tcpdump output for a 10ms RTT, which is quite standard. You can see 5 packets are sent, with a delay of more than 1 ms. 07:58:52.616379 IP 10.246.11.51.39905 > 10.246.11.52.41276: S 2187811646:2187811646(0) win 29200 <mss 1460,nop,nop,sackOK,nop,wscale 6> 07:58:52.626575 IP 10.246.11.52.41276 > 10.246.11.51.39905: S 81785763:81785763(0) ack 2187811647 win 29200 <mss 1460,nop,nop,sackOK,nop,wscale 7> 07:58:52.626642 IP 10.246.11.51.39905 > 10.246.11.52.41276: . ack 1 win 457 07:58:52.626671 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 1:2921(2920) ack 1 win 457 07:58:52.627740 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 2921:5841(2920) ack 1 win 457 07:58:52.628815 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 5841:8761(2920) ack 1 win 457 07:58:52.629946 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 8761:11681(2920) ack 1 win 457 07:58:52.631054 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 11681:14601(2920) ack 1 win 457 07:58:52.637147 IP 10.246.11.52.41276 > 10.246.11.51.39905: . ack 2921 win 274 07:58:52.637207 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 14601:17521(2920) ack 1 win 457 07:58:52.638117 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 17521:20441(2920) ack 1 win 457 07:58:52.638114 IP 10.246.11.52.41276 > 10.246.11.51.39905: . ack 5841 win 320 07:58:52.639011 IP 10.246.11.51.39905 > 10.246.11.52.41276: . 20441:23361(2920) ack 1 win 457 You also can tune /proc/sys/net/ipv4/tcp_min_tso_segs from 2 to 1 if you really want... No kernel patches needed... _______________________________________________ Bloat mailing list [email protected] https://lists.bufferbloat.net/listinfo/bloat
