Tracing different threads in DDB

[David P. Reese, Jr.]

How do I get the trace of another thread's stack in DDB?  When breaking
to the debugger from the console, the trace defaults to the interrupt
handler that serviced the break.  The DDB man page says that trace takes
the stack frame as an argument.  Should I just use the thread address
given in ps?

Also, am I reading the output of ps correctly?  The first block is a
listing of anything with a process context.  The second block is a listing
of threads servicing system calls for the above processes and the last
block lists all of the system threads?

-- 
   David P. Reese, Jr.                                     daver at xxxxxxxxxxxx
                                               http://www.gomerbud.com/daver/