Re: [RFC PATCH kernel] powerpc/xive: Drop deregistered irqs

On Sun, 2019-07-14 at 21:44 +0200, Cédric Le Goater wrote:

quoted

Well, best is probably to do just that though, but call it something
like ppc_md.orphan_irq() or something like that instead. Another option
as you mention is to try to scrub queues, but that's trickier to do due
to the lockless nature of the queue handling.

When the IRQ is shutdown, couldn't we cleanup the CPU EQ by filtering 
all the dangling entries, and replacing them with zeroes ? That would
be alternative 1, but I don't think we need to scan all cpus. The last
target should be enough.

It's a bit tricky due to the lockless nature of the queues...

Cheers,
Ben.