On Mon, Nov 30, 2009 at 02:37:03PM +0000, Russell King - ARM Linux wrote:

Now, at the risk of covering old ground, how about we have two separate
irqaction lists, one for handlers to be called with irqs disabled and
one for handlers with irqs enabled.  We run the irqs-disabled list
first, naturally with irqs disabled.  If, at the end of that run (or
maybe after each handler), IRQs have ended being enabled, print some
diagnostics.  (We're going to need something like this to ensure that
drivers interrupt handlers don't enable IRQs themselves.)  Then enable
IRQs and run the irqs-enabled chain.

Oh, and the other interesting thing to do may be to have a way of
measuring how much time irq handlers run for, so that handlers taking
an excessive time (more than 0.5ms or so - thinking about the 1000Hz
timer rate found on some arches) can be targetted.