Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS]

William Lee Irwin III
2007-04-17T23:09:59Z

On Tue, Apr 17, 2007 at 04:00:53PM -0700, Michael K. Edwards wrote:
> Works, that is, right up until you add nonlinear interactions with CPU
> speed scaling. From my perspective as an embedded platform
> integrator, clock/voltage scaling is the elephant in the scheduler's
> living room. Patch in DPM (now OpPoint?) to scale the clock based on
> what task is being scheduled, and suddenly the dynamic priority
> calculations go wild. Nip this in the bud by putting an RT priority
> on the relevant threads (which you have to do anyway if you need
> remotely audio-grade latency), and the lock affinity heuristics break,
> so you have to hand-tune all the thread priorities. Blecch.
[...not terribly enlightening stuff trimmed...]

The ongoing scheduler work is on a much more basic level than these
affairs I'm guessing you googled. When the basics work as intended it
will be possible to move on to more advanced issues.

-- wli