[Crash-utility] Why are there two ways of getting register values for active tasks?

Hi, all. I have a question on the implementation of get_netdump_regs_x86_64(). Currently, in order to get register values for active tasks, only panic task makes use of note information. On the other hand, other active tasks search stack frame for registers saved at nmi switch. However, crash dump contains the note information for every CPUs, so I think it uncessary to search stack frame. Could anyone tell me why here is implemented this way? Thanks. HATAYAMA, Daisuke