Re: [RFC PATCH 0/7] sched: cpufreq: Remove magic margins

[Lukasz Luba]

Hi Daniel,

On 9/8/23 13:51, Daniel Bristot de Oliveira wrote:
> On 9/7/23 15:45, Lukasz Luba wrote:
> > > > > RT literatur mostly methinks. Replacing WCET with a statistical model of
> > > > > sorts is not uncommon, the argument goes that not everybody will have
> > > > > their worst case at the same time and lows and highs can commonly cancel
> > > > > out and this way we can cram a little more on the system.
> > > > >
> > > > > Typically this is proposed in the context of soft-realtime systems.
> > > >
> > > > Thanks Peter, I will dive into some books...
> > >
> > > I would look at academic papers, not sure any of that ever made it to
> > > books, Daniel would know I suppose.
> >
> > Good hint, thanks!
>
> The key-words that came to my mind are:
>
> 	- mk-firm, where you accept m tasks will make their deadline
> 	           every k execution - like, because you run too long.
> 	- mixed criticality with pWCET (probabilistic execution time) or
> 		  average execution time + an sporadic tail execution time for
> 		  the low criticality part.
>
> mk-firm smells like 2005's.. mixed criticality as 2015's..present.
>
> You will probably find more papers than books. Read the papers
> as a source for inspiration... not necessarily as a definitive
> solution. They generally proposed too restrictive task models.
>
> -- Daniel

Thanks for describing this context! That would save my time and avoid
maybe sinking in this unknown water. As you said I might tread that
as inspiration, since I don't fight with life-critical system,
but a phone which needs 'nice user experience' (hopefully there are
no people who disagree) ;)

Regards,
Lukasz