Re: [RFC] Processing of raised_list can stall if an IPI/interrupt is missed

[Thomas Gleixner]

On Tue, Mar 03 2026 at 20:29, Peter Zijlstra wrote:

> On Tue, Mar 03, 2026 at 04:07:15PM -0300, Herton R. Krzesinski wrote:
>
>> Or may be it's not worth changing this since this is rare and missed self IPI should
>> not be expected?
>
> IPIs going missing is certainly unexpected; although kernel/smp.c has
> much debugging crud for similar scenarios (AFAIK all of them related to
> virt).
>
> If IPIs go missing your system *will* go funny in one way or another.
> I'm not totally against building in some fallback, but we should
> definitely consider it dodgy/buggy if we do detect one has gone
> walk-about.

Indeed and there is enough code by now which relies on the pristine IPI
context when the architecture supports it, so basically reverting this
change is going to create a boatload of other hard to debug problems.

Thanks

        tglx