On Fri, 2005-04-08 at 14:50, Jack O'Quin wrote:
> Jan Depner <eviltwin69@email-addr-hidden> writes:
>
> > On Fri, 2005-04-08 at 12:37, Lee Revell wrote:
> >> Personally I think you're wasting your time. Ingo's RT preempt patches
> >> let you do hard realtime with Linux using the existing driver base.
>
> > I'm not sure why he's trying to do this because for audio the
> > latest patched kernels appear to be more than adequate. That said,
> > I don't think you can get a guaranteed 15 microsecond interrupt
> > response with anyone's patches to the standard kernel. I wouldn't
> > call what we have now hard real-time. More like soft real-time.
> > Maybe when MontaVista gets done...
>
> Agreed.
>
> The Linux kernel will always be "soft" realtime. They can never
> *guarantee* specific interrupt response latencies, because too much
> kernel code can come along later and mess it all up by disabling
> interrupts or holding locks.
>
> What many people overlook is that for most practical purposes, soft-RT
> is what they really want. Hard-RT is only appropriate for a few
> specialized imbedded systems.
>
> Thanks to the hard work of Ingo, Lee and many other folks, recent
> Linux kernels provide excellent soft-RT, right out of the box. With
> Ingo's RT preempt patches, the results are world-class. There will
> always be "two steps forward, one step back" regressions, but those
> fixes keep getting migrated into the base kernel, and the general
> trend is quite encouraging.
Please, don't think I was being disparaging. I am absolutely
thrilled with the kernel work that has been going on. This thing
rocks! The last I heard (from contractors working for us who were doing
soft real-time on - shudder - Windoze) M$ can only get you to about 30
milliseconds.
Jan
Received on Sat Apr 9 00:15:19 2005
This archive was generated by hypermail 2.1.8 : Sat Apr 09 2005 - 00:15:19 EEST