[RFC][PATCH 6/8] sched,idle: Avoid spurious wakeup IPIs

[Peter Zijlstra]

On Fri, May 09, 2014 at 03:40:34PM +0100, Catalin Marinas wrote:

> I wonder why we still need TIF_POLLING_NRFLAG for arm64. It was on arm
> until commit 16a8016372c42c7628eb (sanitize tsk_is_polling()). On arm64
> we use wfi for idle or a firmware call but in both cases the assumption
> is that we need an interrupt for waking up.
> 
> So I think we should remove this macro for arm64.

Does ARM64 support idle=poll? If so, you could keep it for that,
otherwise it does indeed appear to be pointless.

As to 32bit ARM, are there SMP chips which do not have WFI?