NMI fails to generate vmcore when the system is hung

Issue

• When the system is hung, sending an NMI through the hardware management console such as Dell iDRAC (web console or racadm), HPE iLO, or Cisco CIMC does not trigger a kernel panic. However, the same action works as expected when the system is responsive. As a result, a vmcore cannot be generated via NMI when the system is in a hung state.

• The system is enabled with below NMI panic parameter,  but it is not responding to NMI when it is in hang state:

  kernel.unknown_nmi_panic=1 
  kernel.panic_on_io_nmi=1
  kernel.panic_on_unrecovered_nmi=1