> But the problem that the origonal poster reported was  a  restriction
>  of  the "length" parameter - his test seems to demonstrate that
> under Xenomai the legth must be a multiple of the page sise, while in
> plain Linux no such restriction exists (I can provide test  code  for
> that case, if wanted).

Hmm. My code does round the length to a multiple of the page size too. I'm pretty sure I would not have done this if it was not required but my svn notes are not explicit on this. The man page could be considered ambiguous: "EINVAL We  don’t  like  start,  length, or offset (e.g., they are too large, or not aligned on a page boundary)." but only with a liberal reading of the sentence.

hth

                                      - Tom

--
Thomas Lockhart
Supervisor, Distributed and Real-time Group
Instrument Software and Science Data Systems
Caltech/JPL