On Tue, Mar 17, 2026 at 09:17:05AM +0000, David Laight wrote:

On Mon, 16 Mar 2026 23:53:22 -0700
Ankur Arora [off-list ref] wrote:

quoted

David Laight [off-list ref] writes:

quoted

On arm64 I think you could use explicit sev and wfe - but that will wake all
'sleeping' cpu; and you may not want the 'thundering herd'.  

Wouldn't we still have the same narrow window where the CPU disregards the IPI?

You need a 'sevl' in the interrupt exit path.

No need to, see the rule below in
https://developer.arm.com/documentation/ddi0487/maa/2983-beijhbbd:

R_XRZRK
  The Event Register for a PE is set by any of the following:
  [...]
  - An exception return.

-- 
Catalin