Messages in this thread | | | Subject | Re: periods and deadlines in SCHED_DEADLINE | From | Raistlin <> | Date | Sat, 10 Jul 2010 23:52:32 +0200 |
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On Sat, 2010-07-10 at 22:08 +0200, Harald Gustafsson wrote: > > That is a very delicate point, the whole reason SCHED_FIFO and friends > > suck so much is that they don't provide any kind of isolation, and thus, > > as an Operating-System abstraction they're an utter failure. > > > > If you take out admission control you end up with a similar situation. > > OK, I see your point, and I also want to keep the isolation, its just > that I thought that the complexity might be too large to be accepted > by mainline. Let's work towards a solution with good admission > control, i.e. having more complex admission control to handle this. > Indeed. I think things might be done step by step, relaxing the constraints as long as we find better solutions.
> > Embedded people can of course easily hack in whatever they well fancy, > > and adding the 'yes_I_really_want_this_anyway' flag or even taking out > > admission control all together is something the GPL allows them to do. > > Not an option I would like to pursue, it should be possible to get a > working solution without this. > Yeah, I see your point and agree with it. Btw, I think that, even in the configuration described by Peter, if you --as an embedded system engineer-- have the full control of your device/product, you can avoid having any hard-rt task. Then, if you only have soft ones, you'll get the benefit of having the possibility of setting D!=P without suffering of any interference... Am I right?
I think this could be a viable solution, at least until we have something better to relax assumptions on the schedulability test for hard tasks, isn't it?
Regards, Dario -- <<This happens because I choose it to happen!>> (Raistlin Majere) ---------------------------------------------------------------------- Dario Faggioli, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy)
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