On Fri, Aug 07, 2020 at 03:49:41PM +0200, luca abeni wrote: > Hi Peter, > > peterz@xxxxxxxxxxxxx wrote: > > One thing I considerd was scheduling this as a least-laxity entity -- > > such that it runs late, not early > > Are you thinking about scheduling both RT and non-RT tasks through > deadline servers? If yes, Maybe, I initially considered this for mixed criticality, where the 'soft' class would run EDF and the 'hard' class would run LLF (or the other way around, I can't quite remember how I figured it). If you restrict the hard class to single CPU assignment (IOW the UP case) and ensure that u_llf + U_gedf/N < 1, it should just work out. But I shelved all that after I heard about that other balancer idea Danial was suppose to be working on ;-))) > then I think that using something like > laxity-based scheduling for the SCHED_OTHER server can be a good idea > (but then we need to understand how to combine deadline-based > scheduling with laxity-based scheduling, etc...) /me consults notes, EDZL is I think the closest thing there. > Or are you thinking about keeping the SCHED_OTHER server throttled > until its laxity is 0 (or until its laxity is lower than some small > value)? In this second case, the approach would work even if RT tasks > are not scheduled through a server (but I do not know which kind of > performance guarantee we could provide). That would certainly be sufficient for OTHER servers I think.
