Re: [RFC 8/8] Do not reclaim the whole CPU bandwidth

From: Luca Abeni
Date: Fri Jan 15 2016 - 04:49:55 EST


On Fri, 15 Jan 2016 09:50:04 +0100
Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
[...]
> The trouble is with interfaces. Once we expose them we're stuck with
> them. And from that POV I think an explicit SCHED_OTHER server (or a
> minimum budget for a slack time scheme) makes more sense.
>
> It provides this same information while also providing more benefit,
> no?
>From an interface point of view, I agree.

> > >That would maybe fit in nicely with the DL based FIFO/RR servers
> > >from this other pending project.
> > Yes, this reminds me about the half-finished patch for RT
> > throttling using SCHED_DEADLINE... But that patch needs much more
> > work IMHO.
>
> IIRC two years ago at RTLWS there was a presentation that the SMP
> issues were 'solved' and they would be posting the patches 'soon'.
Do you mean this paper?
http://retis.sssup.it/~nino/publication/rtlws14bdm.pdf

I started from that patch, and I have something that "basically works",
but I am still discussing some theoretical and implementation issues
with the paper's authors.



Luca