On May 4 2010, Terry Dontje wrote:
Is a configure-time test good enough? For example, are all Linuxes the same in this regard. That is if you built OMPI on RH and it configured in the new SysV SM will those bits actually run on other Linux systems correctly? I think Jeff had hinted to this similarly when suggesting this may need to be a runtime test.
A very good question. It is clearly NOT good enough for the affinity problems I mentioned, because they are changeable by system configuration, but this is more basic. I don't remember seeing any parameters to change the behaviour of System V shared memory, as distinct from its constants. Five years ago, I would have guessed "no", because this is exactly the sort of area where the single-CPU and multi-CPU kernels differed, but I believe that there is less of that sort of thing nowadays. However, it's worth watching out for. Regards, Nick Maclaren.
