On Fri, 3 Jun 2011 09:44:36 -0400 John Baldwin wrote: JB> Please try this change. What is happening is that you have a remaining JB> window that is smaller than the window scale. You are receiving zero JB> window updates that are received ok (becuase the socket buffer isn't JB> completely empty), and that advance rcv_nxt. However, tcp_output() is JB> not advancing rcv_adv because 'recwin' is calculated as zero. My JB> invariants had assumed that the ACK that gets forced out for a reply JB> to a zero window probe would move rcv_adv, but that isn't happening. JB> This patch will allow rcv_adv to advance when a zero window probe is JB> ACK'd. I'm not sure if this is the best way to fix this, but I think JB> it will fix it:
JB> Index: tcp_output.c JB> =================================================================== JB> --- tcp_output.c (revision 222565) JB> +++ tcp_output.c (working copy) JB> @@ -1331,7 +1331,7 @@ out: JB> * then remember the size of the advertised window. JB> * Any pending ACK has now been sent. JB> */ JB> - if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv)) JB> + if (recwin >= 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv)) JB> tp->rcv_adv = tp->rcv_nxt + recwin; JB> tp->last_ack_sent = tp->rcv_nxt; JB> tp->t_flags &= ~(TF_ACKNOW | TF_DELACK); Sorry for the delay -- I was offline :-). Thanks, with the patch I can't reproduce the issue. I am going to run additional tests in the coming days and will inform you if I find something suspicious. -- Mikolaj Golub _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
