[Gllug] Erratic Mouse Behaviour

[Nix]

On Sun, 9 Dec 2001, William Palfreman stipulated:
> On 8 Dec 2001, Nix wrote:
>> (thank goodness I'd remembered about the auto-reboot-on-panic option.)
> 
> I didn't know that you could set this.  It would be very handy on a
> headless machine, especially a co-lo.

Quite so. It's in, er, /proc/sys/kernel/panic:

,----
| panic 
|    The value in this file represents the number of seconds the kernel
|    waits before rebooting on a panic. When you use the software
|    watchdog, the recommended setting is 60. If set to 0, the auto
|    reboot after a kernel panic is disabled, this is the default
|    setting.
`----

btw, does anyone know how to get a Sun Netra to turn itself on
automatically after a power cut? In common with many soft-power systems
the thing comes up turned off. Half my other machines do too but they're
PCs so I'd expect them to be stupid; but there *must* be something in
the OpenPROM tree that I haven't noticed to change this for decent
hardware.

(If the Sun doesn't come up, the network is cleft in twain... see
 _Darkness_, Byron... ;) )

>                                        Where would I find this option?  
> Come to think of it, "Aieee, killing interrupt handler" has probably
> been followed by a spontaneous reboot (most/all?) the times I've seen
> it.  Would this be a default set by the distro?

Nope, that's caused by sheer kernel fuckage. That message means you've
reached do_exit() from an interrupt handler; while in an interrupt,
you're not in a process context, so you're killing an essentially random
process. The process this kills will be the one that was active when the
interrupt came in; the likelihood is that this is the idle process (proc
0) (there's a message about this, too). With the idle task dead, the
system's death is certain, so it panics.

The top of kernel/exit.c:do_exit() reads:

,----
| 	if (in_interrupt())
| 		printk("Aiee, killing interrupt handler\n");
| 	if (!tsk->pid)
| 		panic("Attempted to kill the idle task!");
`----

-- 
`The situation is completely under control. All of them were killed.'
     --- Alim Razim, for the Northern Alliance, demonstrating fine
         command of traditional Afghan prisoner control techniques.

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