Re: your mail

Steven Rostedt
2016-11-16T14:25:50Z

On Wed, 16 Nov 2016 11:40:14 +0100
Peter Zijlstra <peterz@infradead.org> wrote:

> On top of which, the implementation had issues; now I know you're the
> blinder kind of person that disregards everything not in his immediate
> interest, but if you'd looked at the patch you'd have seen he'd added
> code the idle entry path, which will slow down every single to-idle
> transition.

Isn't to-idle a bit bloated anyway? Or has that been fixed. I know
there was some issues with idle_balance() which can add latency to
wakeups. idle_balance() is also in the to-idle path.

Note, that this is a sched feature which would be a nop (jump_label)
when disabled. And I'm sure it could also be optimized to be a static
inline as well when it is enabled.

I'm not saying we need to go this approach, but I'm just saying that
the to-idle issue is a bit of a red herring.

-- Steve