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SubjectTCP Stall
Hello!
Good news, this patch, posted here earlier today, solves most of the
TCP Stall problem:


--- linux-2.1.32/net/ipv4/tcp_input.c.orig Mon Apr 7 23:27:28 1997 +++
linux/net/ipv4/tcp_input.c Mon Apr 7 23:27:50 1997
@@ -739,7 +739,7 @@

when = tp->rto - (jiffies - skb->when);

- if (when <= 0)
+ if (sk->retransmits)
{
tp->retrans_head = NULL;
/*
-----------------
The attached program can be used to test for the TCP Stall problem.
It's output (after the patch) is:
Stall at pk:38 tot:54094 time:860459936.331466 3020 bps
Stall at pk:137 tot:198634 time:860459982.441429 3103 bps
Stall at pk:198 tot:287694 time:860460015.351438 2968 bps
Stall at pk:263 tot:382594 time:860460048.251453 2947 bps
Stall at pk:328 tot:477494 time:860460081.261476 2932 bps
Stall at pk:394 tot:573854 time:860460114.81429 2933 bps
Stall at pk:461 tot:671674 time:860460147.441400 2933 bps
Stall at pk:525 tot:765114 time:860460180.371431 2921 bps
Stall at pk:588 tot:857094 time:860460213.311417 2906 bps
Stall at pk:653 tot:951994 time:860460246.371443 2903 bps
Stall at pk:720 tot:1049814 time:860460279.551432 2907 bps
Stall at pk:786 tot:1146174 time:860460312.521404 2908 bps
Stall at pk:852 tot:1242534 time:860460345.481591 2910 bps
Stall at pk:919 tot:1340354 time:860460378.451448 2914 bps
Stall at pk:986 tot:1438174 time:860460411.511421 2917 bps
Stall at pk:1053 tot:1535994 time:860460444.791429 2918 bps

The stalls are very short now and I get a reasonable speed from the
28.8 kb link in spite of them. The program considers any timeout in
excess of a few seconds to be a stall so it's fairly critical about
what it reports.

The program's output before the patch showed about 150 to 300 bps.


Cheers,
Dick Johnson
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Richard B. Johnson
Project Engineer
Analogic Corporation
Voice : (508) 977-3000 ext. 3754
Fax : (508) 532-6097
Modem : (508) 977-6870
Ftp : ftp@boneserver.analogic.com
Email : rjohnson@analogic.com, johnson@analogic.com
Penguin : Linux version 2.1.32 on an i586 machine (66.15 BogoMips).
Warning : I read unsolicited mail for $350.00 per hour. Supply billing address.
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