Re: [ck] Re: [ANNOUNCE] RSDL completely fair starvation freeinteractive cpu scheduler

[jos poortvliet]

Op Monday 12 March 2007, schreef Con Kolivas:
> On Tuesday 13 March 2007 01:14, Al Boldi wrote:
> > Con Kolivas wrote:
> > > > > The higher priority one always get 6-7ms whereas the lower priority
> > > > > one runs 6-7ms and then one larger perfectly bound expiration
> > > > > amount. Basically exactly as I'd expect. The higher priority task
> > > > > gets precisely RR_INTERVAL maximum latency whereas the lower
> > > > > priority task gets RR_INTERVAL min and full expiration (according
> > > > > to the virtual deadline) as a maximum. That's exactly how I intend
> > > > > it to work. Yes I realise that the max latency ends up being longer
> > > > > intermittently on the niced task but that's -in my opinion-
> > > > > perfectly fine as a compromise to ensure the nice 0 one always gets
> > > > > low latency.
> > > >
> > > > I think, it should be possible to spread this max expiration latency
> > > > across the rotation, should it not?
> > >
> > > There is a way that I toyed with of creating maps of slots to use for
> > > each different priority, but it broke the O(1) nature of the virtual
> > > deadline management. Minimising algorithmic complexity seemed more
> > > important to maintain than getting slightly better latency spreads for
> > > niced tasks. It also appeared to be less cache friendly in design. I
> > > could certainly try and implement it but how much importance are we to
> > > place on latency of niced tasks? Are you aware of any usage scenario
> > > where latency sensitive tasks are ever significantly niced in the real
> > > world?
> >
> > It only takes one negatively nice'd proc to affect X adversely.
>
> I have an idea. Give me some time to code up my idea. Lack of sleep is
> making me very unpleasant.

You're excited by RSDL and the positive comments, aren't you? Well, don't 
forget to sleep, sleeping makes ppl smarter you know ;-)

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