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Re: [Xen-devel] More on networking hang

> I saw something go by on the list a week or so ago about network hangs, 
> and I may be observing something similar.
> The basic setup is: two guest domains running apache, and a different 
> box running httpperf against them, 100 requests per second for the same 
> 100kbyte file.
> This runs ok for a time, then suddenly chokes and all traffic comes to a 
> stop. Then a few seconds later traffic seems to pick up again.
> This behavior is not observed with a workload of 40 requests/second. At 
> 80/second, the problem starts appearing, but not very frequently.
> We can provide sufficient detail if anyone wants to try to reproduce this.

Just to check I understand your setup: You have a domain 0
implementing bridging, then a domain 1 and a domain 2 each
running apache.

When the domain chokes, do you you see any drops or errors in the
stats as reported by ifconfig?

It would be good to enable the debugging printf's in both the
netfront and netback drivers.

Can you repeat this with a single non-0 domain? Can you repeat it more
easily by generating a background network load in dom0?

BTW: Have you got CONNECTION_TRACKING compiled into the dom0
kernel?  This seems to cripple Linux performance, hence it was
recently made a module in our config.


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