Re: panic: in_pcblookup_local (?)

On 1 May 2013, at 19:03, Glen Barber wrote:

>> I'll need to catch up on this thread later, but a few questions:
>> 
>> Do we know if the application in question is multithreaded, and
>> if so, might it be attempting concurrent operations on this socket?
> 
> I do not know if zabbix-agent is multithreaded, but cf-agent is.

If in DDB, it would be useful to do a "ps" so we can identify threads in the process, and in particular, whether they might be in the kernel around the moment of the panic.

> I will follow up with this information as soon as possible.

Thanks. Do keep around as much information as you can from DDB, crashdumps, etc. A useful set of things to keep from DDB includes the initial panic information and trap frame, "show pcpu", "show allpcpu", "trace", "alltrace", "ps", and if WITNESS is compiled in, "show locks" and "show alllocks". On busy systems, all the backtraces add up to a lot of space, so you might hold onto that rather than e-mail it, but contain useful information. Often, debugging this sort of race condition involves looking at what other network-centred threads are doing -- e.g., device-driver ithreads, netisr, other involved user threads. You may be able to extract much of that information using ps on the crashdump (not sure if procstat is there yet for crashdumps) -- if so, be sure to use -H (or whatever the argument is to print thread, not just process, information).

Off to a formal dinner, but back later!

Robert