Bad info on RTAI

Paolo Mantegazza mantegazza at aero.polimi.it
Thu Oct 21 10:58:06 CEST 2004


Ciao,

Not so many apologies for boring you with this topic (again) but, after 
all, this is my list also.

I've been pointed to an article published a week ago on Linux Weekly 
News (LWN) titled: "Approaches to realtime Linux"

Overall it could be OK but it made me very very angry with the following:

".... Working with RTAI still requires writing kernel-mode code to 
handle the hard realtime part of the task."

Then it goes on with a more extended and substantially well done 
presentation of FUSION.
No mention, neither of LXRT and its capabilities (see ahead) nor of 
FUSION being based on the same LXRT idea.

To my knowledge, LWN has always been a fair source of information and it 
never denied publishing any RTAI related annoucement I forwarded to 
them. In this case nonetheless, by stating that what is considered just 
a "not to use any more" legacy only mode of operation is the RTAI only 
working mode, it really took side with the worst FUD mouthing about 
RTAI. In any case I learned to just look and pass by such FUD but, since 
LWN is much more spread than RTAI, I do not want to let RTAI users 
misled by reading it without a rebuttal.

Thus I rebate immediately to all of you to not get confused by things 
such as the one reported above.

Forget it and remind what I've said many many times already. RTAI works, 
(it has been the first):
- in hard real time mode in user space
- it has been so for more than 4 years
- to the point that you can now even write interrupt handlers in user space
- the related scheduler, LXRT, works symmetrically inter/intra kernel 
/user lands, in soft/hard real time mode, using native Linux schedulable 
objects only
- with LXRT you can work as you like, in any mode, everywhere.
- the legacy kernel land only schedulers are going to disappear
- news/infos like the one reported are speeding up the adoption of LXRT 
as the only scheduler sooner than expected.

I cannot restraint from saying that, even after counting up to 10, I'm 
really fed up.

Paolo.





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