Receiving 16k messages via tcp on p2020 via Linux sometimes delays

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Receiving 16k messages via tcp on p2020 via Linux sometimes delays

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Contributor I

I am running kernel

Linux freescale 2.6.32-svn1457 #178 SMP Thu Jul 7 10:40:12 EDT 2011 ppc unknown

If I send 10,000 16k packets over TCP, the P2020 will receive most of them in about 1.5 microseconds. However,

about 500 times in this test, not all characters are received and it takes about 300 milliseconds for the

packet to come in.

Probably what's happening is that the linux tcp stack is timing out at 200 ms before continuing to receive the

packet stream.

I can ameliorate the problem by sending back a \0 byte ever time I receive a partial packet. Then all runs well,

as the stack is piggy-backing the ACK/NAK on this packet.

But, is there either:

1. A patch to the linux kernel to resolve this issue?

2. Or, is that a network parameter I can change to do same?

Thank You,

Cal Page

Teradyne

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Contributor I

I resolved this problem by back-porting net/ipv4 from linux-2.6.32.60 into the current tree.

Two modules didn't compile: devinet.c and fib_frontend.c. These involved features my current client did not use, so these two files were left alone.

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Contributor I

Actually, I am still seeing the problem, so am still searching for a solution.

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