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

[Peter Williams]

Al Boldi wrote:
> 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.

No.  I'm thinking about different schedulers on a single run queue.  I 
don't think that it's a good idea.

> 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.

I think that you need to think a bit harder about the consequences of 
such a system.  The word "chaos" springs to mind.

Peter
--
Peter Williams                                   pwil3058@xxxxxxxxxxxxxx

"Learning, n. The kind of ignorance distinguishing the studious."
 -- Ambrose Bierce
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/