side note: sysctl with mlxen devices can cause kernel panics

[John Jasen]

Forgive the short report. I imagine this is easily reproduced if its a
software error -- less so if the nut on the end of the keyboard needs
adjustment.

I was trying to loop through the mlxen cards I have on the system,
basically tweaking hw.mlxenNUM.conf.rx_size, tx_size, pkt_rate_low and
pkt_rate_high.

It seems doing this too often or perhaps doing it in the middle of
several data streams can be hazardous -- namely that it will panic the box.

There have been times I've been able to tickle those sysctl settings
multiple times without issue, and there have been times like today,
where the system panicked on my first loop.

I can provide info from /var/crash on it, for anyone who wants it.

Thanks!