Performance with entirely unpatched 2.6.22 kernel

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_RATEB94967295
Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_update_x: X_prevt98324, X_now996648, X_calc=0, X_recv887895
Jul 20 18:09:41 gerrit kernel: ccid3_update_send_interval: t_ipi”, deltaG, s15, X996648
Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_packet_recv: client(f484d030), RTT27us (sample03us), s15, p=0, X_calc0, X_recv887895, X996648
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_RATE20590
Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_parse_options: client(f484d030), LOSS_EVENT_RATE1
Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_update_x: X_prevY08095, X_now(41180, X_calcU50695, X_recv20590
Jul 20 18:09:41 gerrit kernel: ccid3_update_send_interval: t_ipiI8, delta$9, s15, X(41180
Jul 20 18:09:41 gerrit kernel: ccid3_hc_tx_packet_recv: client(f484d030), RTT39us (sample 70us), s15, p2258, X_c
alcU50695, X_recv20590, X(41180
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