Messages in this thread | | | Subject | Re: RFC for a new Scheduling policy/class in the Linux-kernel | From | Raistlin <> | Date | Mon, 13 Jul 2009 11:55:55 +0200 |
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On Sat, 2009-07-11 at 20:28 +0200, Peter Zijlstra wrote: > > There are still some issues left to solve, for instance how to best > > handle sporadic tasks, and whether or not deadline-miss should be allow, > > or just 'bounded deadline tardiness'. Either way, EFF should be able to > > handle it. Then, there are problems concerning blocking of tasks. One > > solution would be BWI or PEP, but I have not had the time to read > > properly through those, but from what I've gathered a combination of BWI > > and PEP looks promising (anyone with good info about BWI and PEP - feel > > free to share! (-: ). > > Our SSSUP friends have a BWI paper here: > > http://retis.sssup.it/~tommaso/publications/OSPERT-2008.pdf > And here we are! :-)
The paper Peter pointed you to mainly describes the work I did some months ago to implement BandWidth Inheritance inside one real-time Linux variant of us (ReTiS Lab, in Pisa, Italy)... Feel free to ask anything related to it directly to me.
It is exactly implemented as a "proxy execution" protocol and things were easy there, since --for now-- the framework I was talking about is UP-only! :-(
Now we are back on work on it, especially thinking on how to extend the protocol to SMP architectures...
> Thing is, both BWI and PEP seems to work brilliantly on Uni-Processor > but SMP leaves things to be desired. Dhaval is currently working on a > PEP implementation that will migrate all the blocked tasks to the > owner's cpu, basically reducing it to the UP problem. > Nice... Only one question, doesn't this impact with task affinity related issues?
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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