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Re: [rtl] Networking With RT-Linux



yodaiken@fsmlabs.com writes:

[...]
> In this case realtime network connectivity generally has little value.
> You should be able to get relatively high, stable throughput from the Linux
> non-realtime drivers. 
> 

You are right; the work is basically experimental and part of a larger
project... I hope the Linux non-realtime drivers won't introduce too
much delay due to buffer overfills.

> Something is very wrong with your network. Use tcpdump to analyze.
> 
> What network cards are you using? What is the network setup?
> Is there a router or firewall?

Well, I am sending messages from one departmental network to another,
even though they are in the same building (the networks are
administered by different people, I don't know much about the
setups). For the RTL, I am using a 3com Boomerang; for the non-RT
clients, I don't know, but they should be some 100Mbps Ethernet
cards. However, the problem seems to have disappeared once I
significantly reduced the amount of debug data and the flushing of
stdout.

A new problem is the freezing of the RTL server when the more frequent
RT tasks run every 50ms. At 80ms, it does not freeze. I am yet to
measure how long the RT task invocations take. Could a task that takes
longer than its period freeze the RTL server (Linux or whatever, I
just can't figure out what happens when it freezes)?

Thanks,
Aleks
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