Hello, I'm testing 2.6.18 over an emulated long haul network (using netem with 100ms delay). For some reason if I just rely on the autotuning ffeature of the stack (i.e., no -w to iperf) over a 1GbE link, I can only get ~820Mbps throughput. All the other sysctl tunables (e.g., tcp_rmem, tcp_wmem) have been set to sufficiently large (4096 8388608 20971520). In order to saturate the link I had to specify SO_SND/RCVBUF sizes to, e.g, 13MB using the -w option to iperf, effectively disabling autotuning. I also discovered that the autotuning deficiency seems to reside only on the xmit side, i.e., if i specify -w 13m on the xmit side only I can attain 945Mbps throughput. Also if i increase the delay to 150ms I can only get up to ~615Mbps from autotuning. Am I bumping into some known bugs? Thanks, Jerry - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
