[PATCH] sched/fair: don't use waker's cpu if the waker of sync wake-up is interrupt

[Mike Galbraith]

On Tue, 2021-04-27 at 04:44 +0000, Song Bao Hua (Barry Song) wrote:
>
>
> I agree sync hint might have been overused by other kernel subsystem.
> But this patch will at least fix a case: sync waker is interrupt,
> in this case, the existing task has nothing to do with waker and wakee,
> so this case should be excluded from wake_affine_idle().

I long ago tried filtering interrupt wakeups, and met some surprises.
Wakeup twiddling always managing to end up being a rob Peter to pay
Paul operation despite our best efforts, here's hoping that your pile
of stolen cycles is small enough to escape performance bot notice :)

	-Mike