RE: Buffer problems

["Mark Rivers" <rivers@cars.uchicago.edu>]

Kevin,

I suspect you are seeing the same problem we have seen at Brookhaven.
You can try to reproduce this problem by sending lots of large ping
packets quickly to the IOC.

Here's how I've done it on Mac OSX.

> ping -s1500 -l3000 <ioc>

On Linux I think the command is the same.  Note that you must be root to
do this.

With this command I have managed to irreversibly hang MVME2700 CPUs, so
that they needed to be rebooted.  This happens something like 10-30% of
the time that the ping command is issued.  Other times it causes long
"delays", where the IOC is not capable of network activity, but then it
recovers in 30 seconds or so.

On MVME172 processors I have only managed to induce that latter
behavior, i.e. delays, but not complete hangups requiring reboot.  But I
have not done extensive tests of this.

Mark