Using the magic sysrq key


use SYSRQ-P to dump cpu information a few times

SysRq: Show Regs

EIP: 0010:[<c011251f>] CPU: 0 EFLAGS: 00200296
EAX: 00005305 EBX: 00000000 ECX: 00000000 EDX: c147bfa0
ESI: 00000002 EDI: 00005305 EBP: 00000001 DS: 0018 ES: 0018
CR0: 8005003b CR2: 4001a000 CR3: 0cc66000 CR4: 00000690
Call Trace: [<c0112604>] [<c0112eb7>] [<c011389e>] [<c0113600>] 
[<c010757b>]

look to see how much the EIP changes
if it's in a loop you can spot the small changes in the address
resolve the EIP like in an oops to find out where
deadlocks, lock ordering inversion