Re: [patch] sched: fix scheduling latencies for !PREEMPT kernels

Lee Revell
2004-09-15T00:35:30Z

On Tue, 2004-09-14 at 10:54, Ingo Molnar wrote:
> * Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> > Another thing, I don't mean this to sound like a rhetorical question,
> > but if we have a preemptible kernel, why is it a good idea to sprinkle
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > cond_rescheds everywhere? Isn't this now the worst of both worlds? Why
> > would someone who really cares about latency not enable preempt?
>
> two things:
>
> 1) none of the big distros enables CONFIG_PREEMPT in their kernels - not
> even SuSE. This is pretty telling.
>

I am not sure this means preemption is a bad idea, it just means there's
no point in enabling CONFIG_PREEMPT with the current kernel because it's
not enough of an improvement to make a difference for low latency
applications.

Lee