Re: [PATCH 3/4] sched: introduce synchronized idle injection

From: Jacob Pan
Date: Wed Nov 18 2015 - 09:11:13 EST

On Wed, 18 Nov 2015 09:36:22 +0100
Ingo Molnar <mingo@xxxxxxxxxx> wrote:

> >
> > This patch introduces a scheduler based idle injection method, it
> > works by blocking CFS runqueue synchronously and periodically. The
> > actions on all online CPUs are orchestrated by per CPU hrtimers.
> >
> > Two sysctl knobs are given to the userspace for selecting the
> > percentage of idle time as well as the forced idle duration for each
> > idle period injected.
> What's the purpose of these knobs? Just testing, or will some
> user-space daemon set them dynamically?
yes, it is to be used by userspace daemon such as thermal daemon.
Though there are interests from in kernel thermal governor but that is
another story.

> I also think that naming it 'idle injection' is pretty euphemistic:
> this is forced idling, right? So why not name it CFS_FORCED_IDLE?
yes, it is forced idle. sounds good.
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