em interrupt storm

[Jack Vogel]

On 11/13/06, Bill Moran <wmoran at collaborativefusion.com> wrote:
>
> Just experienced an "interrupt storm" on an em device that disabled a
> server until I could reboot it.
>
> My initial research turned up this thread:
> http://lists.freebsd.org/pipermail/freebsd-current/2005-November/058336.html
>
> Which seems related, even if it is a little old.  I'm aware that there
> have been problems with recent versions of the em driver but I haven't
> been following them closely enough, and there's a LOT of mail traffic
> on this topic.
>
> Note that this is a FreeBSD 5.3-RELEASE-p37 system.  An upgrade is
> possible, but this is a production system and the problem occurs
> infrequently, so I'm reluctant to schedule downtime unless I have good
> reason to believe that it will fix the problem.
>
> Anyone remember if the above problem was fixed in more recent versions,
> or knows enough about the issue to comment on whether I'm barking up
> the correct tree or not?  I'm pretty early in the diagnosis on this,
> but I'm looking for pointers to keep me from doing random upgrades or
> other time-wasting activities.

There were fixes to things that MIGHT be a cause of an interrupt storm
in the em driver, but without knowing more about your specific hardware
and the event when it happened its hard to pontificate :)

As an aside, I would think getting off 5.3 would be desireable in and of
itself :)

Can you give a vmstat -i, a pciconf -l, and maybe messages when the
storm occurred?

Thanks Bill,

Jack