Re: [PATCH 03/16] sched/fair: Disregard idle task wakee_flips in wake_wide

Mike Galbraith
2016-05-23T13:00:50Z

On Mon, 2016-05-23 at 13:00 +0100, Morten Rasmussen wrote:

> The problem then seems to be distinguishing truly idle and busy doing
> interrupts. The issue that I observe is that wake_wide() likes pushing
> tasks around in lightly scenarios which isn't desirable for power
> management. Selecting the same cpu again may potentially let others
> reach deeper C-state.
>
> With that in mind I will if I can do better. Suggestions are welcome :-)

None here. For big boxen that are highly idle, you'd likely want to
shut down nodes and consolidate load, but otoh, all that slows response
to burst, which I hate. I prefer race to idle, let power gating do its
job. If I had a server farm with enough capacity vs load variability
to worry about, I suspect I'd become highly interested in routing.

-Mike