Montavista's "Open Source Real-Time Linux Project" again

Gilles Chanteperdrix gilles.chanteperdrix at
Thu Oct 14 19:55:48 CEST 2004

Karim Yaghmour wrote:
 > (...)
 > to qualify as hard-rt, it must be demonstrated mathematically/
 > algorithmically that a system is truly deterministic. In order to meet
 > such criteria, the proponents of these preemption-on-steriod patches
 > would need to show that _ALL_ software written for Linux in the past
 > is now somehow compatible with hard-rt.

I do not see where this argument lead us: the same is true for RTAI, and
I suspect many people are using RTAI without having done a mathematical
proof of the correctness of its code. People generally assume that their
system is not so strange that running it under heavy load for a few
hours (or days) will not let the hot spots appear. This may look
frightening for people leaving in the dream world of theory, but
concretely, it does not work that bad, and this is actually the approach
used for many "industrial" products, like medicine, cars, genetically
modified food, etc...

As for Montavista announce, it has two sides, the marketing side, which
is not RTAI project's business, and the technical side which is rather
good news. It shows some interest for Ingo Molnar's work, and make it
more likely to be included (even if partially) in Linux.

After all, applications using LXRT or Fusion use Linux calls, this is
what these technologies are all about. Such applications hence benefit
from any Linux responsiveness improvement.


					    Gilles Chanteperdrix.

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