Re: reboot notifier priority definitions

[Neil Brown]

On Tuesday September 11, [e-mail] wrote:
> > 
> > I think this misses the point of reboot notifiers (as I understand
> > it).
> > 
> > There are *only* meant for "physical" sorts of things.
> > The comment in the code says:
> >  *    Notifier list for kernel code which wants to be called
> >  *    at shutdown. This is used to stop any idling DMA operations
> >  *    and the like. 
> > 
> > md, lvm, knfsd and tux have no business registering a reboot notifier.
> > If they have something to shut down, it should be shut down in a
> > higher-level way, such as when a process gets a signal. 
> > 
> Even then: My servers do have watchdog cards. Unfortunately without the
> priority definitions the watchdog card was shut down prior to the oops. Thus,
> due to missing priority, the system did require hitting the reboot button.
> So some well defined priorization is still required.

Fair enough.

Maybe we need one priority for devices,
A lower priority for busses,
An even lower one for watchdogs,

or something like that.
I'll leave to to people who understand hardware configurations and
controllers better than me.

NeilBrown