Messages in this thread | | | Date | Thu, 10 Nov 2016 15:34:13 +0100 | From | luca abeni <> | Subject | Re: [RFD] sched/deadline: Support single CPU affinity |
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On Thu, 10 Nov 2016 12:03:47 +0100 Tommaso Cucinotta <tommaso.cucinotta@sssup.it> wrote:
> On 10/11/2016 10:06, luca abeni wrote: > > is equivalent to the "least laxity first" (LLF) algorithm. > > Giving precedence to tasks with 0 laxity is a technique that is > > often used to improve the schedulability on multi-processor > > systems. > > EDZL (EDF / Zero Laxity first), right? Yes, basically all the "ZL" algorithms (EDZL, but I think I've also seen something like RMZL or similar).
> AFAICR, there's quite a lot of > analysis on EDZL for multi-cores... eg, Insik Shin et al.... > > http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6374195 Yes, this is why I mentined the 0-laxity thing... Of course, here the situation is different (there are tasks that can be migrated, and tasks that cannot), but maybe the 0-laxity analysis can be adapted to this case?
> But, before going the EDZL way, isn't it worthwhile to consider > just splitting tasks among 2 cpus > > https://people.mpi-sws.org/~bbb/papers/pdf/rtss16b.pdf Yes, there are many possible different strategies that can be tested (I think somewhere I saw some semi-partitioned algorithm that was even optimal). I suspect everything depends on the trade-off between implementation complexity and scheduling efficiency.
Luca
> > ? ... we're working at RETIS on simpler ways to make the AC for > these split tasks cases (cc-ing Alessandro) that doesn't need > demand-bound complex analysis... > > My2c, > > T.
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