Re: Fix for SLOW PPP Bug

Mike Black (mblack@csihq.com)
Thu, 11 Apr 1996 08:06:34 -0400

At 02:41 PM 4/10/96 +0300, Linus Torvalds wrote:
>
>I'd suggest changing the "if" case to something like this:
>
> if (!sk->delay_acks || th->fin ||
> sk->bytes_rcv > sk->max_unacked ||
> sk->ato > HZ/2 ||
> tcp_raise_window(sk)) {
> tcp_send_ack(...
> }
> else
> {
>

I tried this patch on a clean 1.3.85 and still had the same problem. 1.3.86
(clean) still has the problem too (ftp from Solaris 5.5 (ddi) to Linux
1.3.86 (picard)): (this DOES work sometimes but here's a case where it doesn't)

06:56:14.452746 ddi.digital.net.20 > picard.csihq.com.1570: P 1:537(536) ack
1 win 25192 (DF)
06:56:14.452746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 537 win 12864
06:56:14.472746 picard.csihq.com.ingreslock > ddi.digital.net.ftp: . ack 277
win 13118
06:56:14.822746 ddi.digital.net.20 > picard.csihq.com.1570: . 537:1073(536)
ack1 win 25192 (DF)
06:56:14.822746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 1073 win 12864
06:56:14.992746 ddi.digital.net.20 > picard.csihq.com.1570: P 1073:1609(536)
ack 1 win 25192 (DF)
06:56:14.992746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 1609 win 12864
06:56:15.192746 ddi.digital.net.20 > picard.csihq.com.1570: . 1609:2145(536)
ack 1 win 25192 (DF)
06:56:15.192746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 2145 win 12864
06:56:15.362746 ddi.digital.net.20 > picard.csihq.com.1570: P 2145:2681(536)
ack 1 win 25192 (DF)
06:56:15.362746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 2681 win 12864
*** why do we get 1073 again?
06:56:15.482746 ddi.digital.net.20 > picard.csihq.com.1570: . 1073:1609(536)
ack 1 win 25192 (DF)
*** why don't we ack 1073 instead of 2681?
06:56:15.482746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 2681 win 12864
06:56:15.682746 ddi.digital.net.20 > picard.csihq.com.1570: P 2681:3217(536)
ack 1 win 25192 (DF)
06:56:15.682746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 3217 win 12864
06:56:15.852746 ddi.digital.net.20 > picard.csihq.com.1570: . 3217:3753(536)
ack 1 win 25192 (DF)
06:56:15.852746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 3753 win 12864
06:56:16.022746 ddi.digital.net.20 > picard.csihq.com.1570: P 3753:4289(536)
ack 1 win 25192 (DF)
06:56:16.022746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 4289 win 12864
06:56:16.182746 ddi.digital.net.20 > picard.csihq.com.1570: . 2681:3217(536)
ack 1 win 25192 (DF)
06:56:16.182746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 4289 win 12864
06:56:16.302746 ddi.digital.net.20 > picard.csihq.com.1570: . 3753:4289(536)
ack 1 win 25192 (DF)
06:56:16.302746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 4289 win 12864
06:56:16.312746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 4289 win
12864 1 win 25192 (DF)
06:56:15.482746 picard.csihq.com.1570 > ddi.digital.net.20: . ack 2681 win 12864
-
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| Mike Black mblack@csihq.com 407-676-5118, x203 |
| Computer Science Innovations, Inc. 407-676-2355 FAX |
| Melbourne FL 32904-2314 http://www.csihq.com |
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