title: Switch to a different cpu thread in gdb
body: <p>First timer here. 
  While doing gdb and getting prdasummary, I know to find the panicked cpu by looking at inPanic, I also find other cpu running one process which I want to find its locals.</p>
  
  <p>Can I switch to a different cpu and see its registers?</p>
  
  <p>Thanks,
  zXi</p>