Re: [ANNOUNCE][RFC] PlugSched-6.4 for 2.6.18-rc2

[Al Boldi <a1426z@gawab.com>]

Peter Williams wrote:
> Al Boldi wrote:
> > Peter Williams wrote:
> >> Al Boldi wrote:
> >>> Peter Williams wrote:
> >>>> Al Boldi wrote:
>
> [bits deleted]
>
> >>>>> It may be really great, to allow schedulers perPid parent, thus
> >>>>> allowing the stacking of different scheduler semantics.  This could
> >>>>> aid flexibility a lot.
> >>>>
> >>>> I'm don't understand what you mean here.  Could you elaborate?
> >>>
> >>> i.e:  Boot the kernel with spa_no_frills, then start X with spa_ws.
> >>
> >> It's probably not a good idea to have different schedulers managing the
> >> same resource.  The way to do different scheduling per process is to
> >> use the scheduling policy mechanism i.e. SCHED_FIFO, SCHED_RR, etc.
> >> (possibly extended) within each scheduler.  On the other hand, on an
> >> SMP system, having a different scheduler on each run queue (or sub set
> >> of queues) might be interesting :-).
> >
> > What's wrong with multiple run-queues on UP?
>
> A really high likelihood of starvation of some tasks.

Maybe you are thinking of running independent run-queues, in which case it 
would probably be unwise to run multiple RQs on a single CPU.

But I was more thinking of a run-queue of run-queues, with the masterRQ 
scheduling slaveRQs, each RQ possible running its own scheduling semantic.


Thanks!

--
Al