panic in 6.3-RELEASE when multi-cast client exits

[gnn at hudson-trading.com]

At Tue, 19 Feb 2008 14:00:56 +0000,
Bruce M. Simpson wrote:
> 
> Rob Watt wrote:
> > Hi.
> >
> > We recently upgraded some of our machines to 6.3-RELEASE and we have been
> > plagued by repeatable panics when our multi-cast client applications exit.
> > Our machines have Intel X5365 processors, LSI MegaSAS 1064R cards, and Intel
> > Pro 1000 MF nic cards (although we have seen this problem with the onboard
> > Intel copper nics as well). We have seen this panic with machines that have
> > Tyan boards as well as Super Micro. I have seen a few postings that seem to
> > refer to related panics, and bug
> > http://www.freebsd.org/cgi/query-pr.cgi?pr=116077 contains a patch that
> > seems like it should address the problem, but our patched system still
> > panics. I have attached the output from 3 of the dumps/backtraces. Dump #1
> > is probably the most useful. I am happy to provide more info if necessary.
> >   
> 
> Some folk reported that they didn't see this problem occur with the code 
> in 7.x, which jibes as I rewrote some of the logic in that branch. It's 
> been nearly a year since I last had time to look at anything related to 
> this.
> 
> My understanding is that 7.0 is getting closer to release status so you 
> may wish to try reproducing the problem there.
> 
> The human resource situation hasn't changed much on my end, though I am 
> getting closer to having time to finishing IGMPv3 (it's needed for other 
> stuff in the future). I haven't been able to reproduce the bug in the 
> PR, which makes suggesting other courses of action difficult.
> 

I can reproduce this panic with a small piece of code I've been
hacking for work.  The code depends on classes that are proprietary
but the program itself is simple and I'll ask work if I can sanitize
it in the next few days.  The program is intended as a multicast
jitter/latency tester, but works well as a general exerciser of the
multicast code.

The panic is basically an issue with terminating a process and
handling the multicast address lists on the interface.  I have not
tracked down the exact cause as yet but am working on it now.

Best,
George