On Sun, 2 Jul 2000, Paul Barton-Davis wrote:
> >What absolutely amazes me about this thread is that the folks who need
> >low latency (we all do really) have stubornly stuck to their guns asking
> >for scheduling garantees despite excellent explainations that this is by
> >definition asking for hard RT.
>
> Because we have (gasp!) empirical measurements that the preemption
> point approach works to satisfy the performance characteristics we've
> outlined.
<quite boring that.. I have enough lab years behind me measuring latency
and bandwidth [and *gasp* others;] to know what you are talking about>
> Thats why we (the original signees of the letter) were interested in
> finding out more about the objections to Ingo's patches.
I understand that. I don't understand ignoring the answers.
> >The problem has been universally ACKed [1]
> ...
> >1. in my experience, this means the problem is doomed.
>
> Except that we've had, in your words "excellent explanations that this
> is by definition asking for hard RT". So if the problem really has
> been ACKed, which I think I accept it has, and if there is really some
> sense that it should be solved, which there might be, doesn't this
> imply, in your own words, that Linux has to incorporate hard real-time ?
?? everything _I_ read said that is stupidity for a GP OS (Linux). 'if
there is really some sense that it should be solved' you say?? Well,
come on.. the volume of traffic in this thread combined with some of the
persons (who didn't mumble) when they responded make that quite clear.
> >and the best currently available
> >work-around universally NAKed [2] on purely technical grounds.
>
> More accurate, I think, to say "purely aesthetic grounds". Its easy to
> demonstrate that Ingo's patches work extremely well. The dispute is
> over what they would do to the kernel in terms of design and/or
> maintainance.
I've played with enough of Ingo's work to not doubt the functionality ;-)
Despute? I haven't heard a designer with a dispute on the issue.. it
seems very cut and dried from my viewpoint. We got a problem.. it's in
deep think. You want an answer _now_, have one, but not one which is
acceptable to designers. Too bad.. end of story until someone thinks
harder. (Ingo indicated he's thinking about it.. powerful medicine)
> >I would wager that Ingo's next (promised) effort will do much better on
> >the technical merit test.
>
> It wouldn't suprise me either. Ingo pulled a rabbit out of a hat the
> last time, and I would judge him quite capable of extracting the TGV
> from a thimble if he tries it again.
I think [1] stated my viewpoint well enough. BTW, the quote fron Larry
that you snipped was the more interesting portion of my (off-line) input.
-Mike
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