interrupts & pmf/legacy shutdown hooks (was Re: CVS commit: src/sys/arch)

[David Young <dyoung%pobox.com@localhost>]

On Tue, Aug 05, 2008 at 07:47:30PM +0200, Matthias Drochner wrote:
> 
> dyoung%pobox.com@localhost said:
> > > Disable interrupts before shutdownhooks are run
> > There is not a consensus that this is the right thing to do
> 
> It has always been that way on all ports, until June.
> It didn't make sense to change this without preparing
> drivers for it, and to do it on two ports only.
> So I think I'm right here.
> 
> jmcneill%invisible.ca@localhost said:
> > The right thing to do is to fix drivers that use shutdownhooks to 
> > register a pmf handler instead, so we can simply stop calling 
> > doshutdownhooks.
> 
> The pmf registered shutdown hooks are also run with interrupts
> disabled. At least for now, but I somehow believe that this
> saves a lot of trouble with interrupt handlers, in particular
> in the shared interrupt case.

Matthias,

It appears to me that you have made the change following ad's finding that
disabling interrupts causes panics, and prior to showing any evidence
that leaving interrupts enabled is actually harmful.  If that was not
reason enough not to change, there are developers who disagree with you
whether interrupts should be disabled or not during shutdown.  Please,
back out the change and discuss it with us on the appropriate forum.

Dave

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933 ext 24