I haven't been able to get to the ground of the problem why the performance is currently so bad, but on a clean, unpatched 2.6.22 kernel (from netdev), I already get packet loss reports on a lossless link (see below). Applying the test-tree patches on top leads to reported loss rates of up to 10 percent. If that happens in the bandwidth-restricted link, then no wonder the performance drops down. Will investigate further, but DCCP may not be the only corner to look for. In any case, I find the many negative (late) delays below also suspicious. Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_parse_options: client(f484d030), LOSS_EVENT_RATE=4294967295 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_update_x: X_prev=7498324, X_now=14996648, X_calc=0, X_recv=11887895 Jul 20 18:09:41 gerrit kernel: ccid3_update_send_interval: t_ipi=94, delta=47, s=1415, X=14996648 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_packet_recv: client(f484d030), RTT=1827us (sample=1803us), s=1415, p=0, X_calc= 0, X_recv=11887895, X=14996648 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-19169 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-19108 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-19047 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18984 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18921 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18857 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18798 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18735 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18673 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18610 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18548 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18487 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18423 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18389 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18327 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18264 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-18200 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_senlay=-2887 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2659 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2455 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2255 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2050 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-1844 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_parse_options: client(f484d030), RECEIVE_RATE=1420590 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_parse_options: client(f484d030), LOSS_EVENT_RATE=31 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_update_x: X_prev=5908095, X_now=2841180, X_calc=5550695, X_recv=1420590 Jul 20 18:09:41 gerrit kernel: ccid3_update_send_interval: t_ipi=498, delta=249, s=1415, X=2841180 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_packet_recv: client(f484d030), RTT=1339us (sample=2070us), s=1415, p=32258, X_c alc=5550695, X_recv=1420590, X=2841180 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-3872 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-3460 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2995 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2612 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2148 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-1682 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-1215 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-749 Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_send_packet: delay=-2610 - To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
