On 16/04/24 at 11:17, Michael Kjörling wrote:
Do I need to set some more settings to ensure that the system will
automatically reboot on a panic? If so, what?

Hi,

In the Linux kernel source are available two options to reboot on panic:

config BOOTPARAM_SOFTLOCKUP_PANIC
        bool "Panic (Reboot) On Soft Lockups"
        depends on SOFTLOCKUP_DETECTOR
        help
          Say Y here to enable the kernel to panic on "soft lockups",
          which are bugs that cause the kernel to loop in kernel
mode for more than 20 seconds (configurable using the watchdog_thresh
          sysctl), without giving other tasks a chance to run.

          The panic can be used in combination with panic_timeout,
          to cause the system to reboot automatically after a
          lockup has been detected. This feature is useful for
          high-availability systems that have uptime guarantees and
          where a lockup must be resolved ASAP.

          Say N if unsure.

and:

config BOOTPARAM_HARDLOCKUP_PANIC
        bool "Panic (Reboot) On Hard Lockups"
        depends on HARDLOCKUP_DETECTOR
        help
          Say Y here to enable the kernel to panic on "hard lockups",
          which are bugs that cause the kernel to loop in kernel
mode with interrupts disabled for more than 10 seconds (configurable
          using the watchdog_thresh sysctl).

          Say N if unsure.

from Documentation/admin-guide/kernel-parameters.txt you can set it as kernel parameter or via sysctls:

        softlockup_panic=
[KNL] Should the soft-lockup detector generate panics.
                        Format: 0 | 1

                        A value of 1 instructs the soft-lockup detector
to panic the machine when a soft-lockup occurs. It is also controlled by the kernel.softlockup_panic sysctl
                        and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
                        respective build-time switch to that functionality.

and the same for "kernel.hardlockup_panic" that it seems it hasn't an help entry in the documentation file, I found it here:


        nmi_watchdog=   [KNL,BUGS=X86] Debugging features for SMP kernels
                        Format: [panic,][nopanic,][num]
                        Valid num: 0 or 1
                        0 - turn hardlockup detector in nmi_watchdog off
                        1 - turn hardlockup detector in nmi_watchdog on
                        When panic is specified, panic when an NMI watchdog
                        timeout occurs (or 'nopanic' to not panic on an NMI
watchdog, if CONFIG_BOOTPARAM_HARDLOCKUP_PANIC is set)
                        To disable both hard and soft lockup detectors,
                        please see 'nowatchdog'.
                        This is useful when you use a panic=... timeout and
                        need the box quickly up again.

                        These settings can be accessed at runtime via
                        the nmi_watchdog and hardlockup_panic sysctls.

To learn more I suggest to install the "linux-source-6.1" package and investigate the "Watchdog" option, it is under "Device Drivers". The BOOTPARAM_SOFTLOCKUP_PANIC and BOOTPARAM_HARDLOCKUP_PANIC options are under "Kernel hacking" → "Debug Oops, Lockups and Hangs".

Cheers
--
Franco Martelli

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