On Tue, Aug 05, 2008 at 12:25:02PM -0600, Chris Friesen wrote:
> I've run into an interesting issue with an Octeon-based board, where it
> just seems to hang. I suspect we're hitting some kind of locking bug,
> and I'm trying to track it down. If it matters, the kernel is quite old
> (heavily patched 2.6.14) and I've got no chance of upgrading it. (The
> usual embedded scenario.)
> I've added some scheduler instrumentation, as well as adding a stack
> dump to the output of the softlockup code.
> In the trace below, is "epc" the program counter at the time of the
> timer interrupt? How does "ra" fit into this, given that the function
> whose address it contains isn't seen in the stack trace until quite a
> ways down?
$LBB378 is an internal symbol. The value of RA may not be very informative
if it was overwritten by a random subroutine call.
> Any insights are greatly appreciated...
You may also try lockdep; it gives much more detailed information though
it's more heavyweight.