Re: RT patch acceptance

From: Nick Piggin
Date: Tue May 31 2005 - 06:09:35 EST

James Bruce wrote:
Nick Piggin wrote:

I have never been in any doubt as to the specific claims I have
made. I continually have been talking about hard realtime from
start to finish, and it appears that everyone now agrees with me
that for hard-RT, a nanokernel solution is better or at least
not obviously worse at this stage.

It is only better in that if you need provable hard-RT *right now*, then you have to use a nanokernel. The RT patch doesn't provide guaranteed hard-RT yet[1], but it may in the future. Any RT application programmer

This was my main line of questioning - what future direction will
do the RT guys want from the PREEMPT_RT work. I was concerned that
hard-realtime does not sound feasable for Linux.


I think where we violently disagree is that in your earlier posts you seemed to imply that a nanokernel hard-RT solution obviates the need for something like preempt-RT. That is not the case at all, and at the

Actually I think that is also where we violently agree ;)
If you look at some of my earlier posts, you'll see I had to
add 'disclaimers' until I was blue in the face. But I don't
blame you for not wanting to crawl through all that / or not
seeing it.

Basically: I know they are orthogonal, and I don't disagree
that generally better scheduling and interrupt latency would be
nice for Linux to have.

Now I'll really stop posting. Sorry everyone.

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