[Asterisk-Dev] How can I see what a thread is doing?

[Matthew Boehm]

Hey guys,
  We are having some problems with asterisk and echo and dropped calls. 
I think it is because we have an old 4 proc P3 machine and can't put 
thru more than 6-7 calls before we start getting echo and major jitter.
  I'm using "top" and are also displaying threads. There are 7 calls up 
right now and I see about 15 threads spread amongst the CPUs. Most of 
them are using 0% cpu. The top two threads are using about 50% each.
  How can I find out what these two threads are doing to use so much 
CPU? Can I do this without causing harm to the system? I've got 71 
peers/users and all but 20 are being "qualified". Can this be using up 
lots of CPU?

Thanks,
Matthew