Re: [PATCH 5/6] x86/irq: WARN_ONCE() if irq_move_cleanup is called on a pending interrupt

From: Thomas Gleixner
Date: Tue May 11 2021 - 10:24:00 EST

On Mon, May 10 2021 at 17:55, H. Peter Anvin wrote:
> From: "H. Peter Anvin (Intel)" <hpa@xxxxxxxxx>
> The current IRQ vector allocation code should be "clean" and never
> issue a IRQ_MOVE_CLEANUP_VECTOR IPI for an interrupt that could still
> be pending. This should make it possible to move it to the "normal"
> system IRQ vector range. This should probably be a three-step process:
> 1. Introduce this WARN_ONCE() on this event ever occurring.
> 2. Move the IRQ_MOVE_CLEANUP_VECTOR to the sysvec range.
> 3. Remove the self-IPI hack.

Actually 2+3 must be combined because _if_ this ever happens then the
self-IPI loops forever.