ssubbarayan wrote:
> Gurus,
> Till vxworks5.5,windriver guys have been using task based model in flat
> address mode for application scheduling,but now with vxworks 6.0
> windriver is playing with idea of using process model over tasks.
> My question is what could be rational behind this?AFAIK,there were not
> much of problems with task models and only advantage of going for
> process model is enabling memory protection.But the adverse effect of
> this would be timing impact due to MMU calculations every time context
> switch happens and Windriver accepts there is performance hit in terms
> of timing but still its deterministic.I am not able to understand how
> this would be deterministic?And how far we can benefit from memory
> protected applications?Because prior versions of vxworks were able to
> achieve good performance even with out memory protection.
> Guys using Linux whats your opinion on this?
> Can some one explain me this?
> Regards,
> s.subbarayan

In my humble opinion, and still after reading the white papers, it is
just a means for lazy or incapable programmers, which adds overhead.
You can develop your code with the MMU on and after some testing and
verifying, that there is no memory violation (program error) you can
switch the MMU off and after the final testing ship your product without
the unnecessary overhead.
I wish I could do the same thing with Linux


Robert Berger
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