On Wed, May 01, 2013 at 02:30:36PM -0400, John Baldwin wrote: > On Wednesday, May 01, 2013 2:08:57 pm Robert N. M. Watson wrote: > > 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). >
So, I am admittedly not too familiar with DDB. In fact, I just now realize the kernel is built without DDB... Additionally, the kernel is built without WITNESS. > You can also grab my kgdb scripts from www.freebsd.org/~jhb/gdb/ > Thanks for these. > Put those in a dir and do 'source gdb6'. You can then run 'ps' to get a good > ps listing that includes threads. You can also use 'thread apply all bt' to > get stacktraces of all threads in kgdb. I believe there is an 'allpcpu' > command that is similar to 'show allpcpu' in DDB. > I have the outputs of 'ps', 'allpcpu', and 'thread apply all bt' saved to separate script(1) files. Is there anything in particular I can look for before uploading the files somewhere public? At quick-ish look though, I did not see anything cf-agent (the current process at time of panic) related. > Robert, in this case he has a full crashdump, so we can get quite a bit of > information from it. > Right, and I can keep anything available for as long as necessary. Glen
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