Subject: Re: [RFC][PATCH 0/2] reworking cause_ipi and adding global doorbell support

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 14 Mar 2017 14:57:20 +1100

On Tue, 2017-03-14 at 12:53 +1000, Nicholas Piggin wrote:
> >   - Load all
> >   - For each byte if set
> >      - clear byte
> >      - then call handler
> 
> Yes. I think that will be okay because we shouldn't get any load-hit-
> store
> issues. I'll do some benchmarking anyway.

We might need a sync still between clearing the byte and calling the
handler no ? Or at least a smp_wmb() to ensure that the clear is
visible before any action of the handler.

Cheers,
Ben.