On Mon, 4 Jun 2012, John Peterson wrote: > BTW, since Metis is using OpenMP (no raw pthreads that I can see) the > proper TLS mechanism is probably something like > > #pragma omp threadprivate(var)
OpenMP uses pthreads under the hood on POSIX systems, IIRC, so thread local storage variables ought to work fine as well. Probably safer for the corner cases to use consistent idioms, though. > I feel like my patch (which effectively makes those variables global) > will potentially break anyone actually running libmesh with > OMP_NUM_THREADS > 1. Almost certainly. > Not sure how much work this would be to fix and test. To fix? Your pragma (suitably replicated and made specific) will probably do it. To test? We can't and shouldn't try to test that unmodified Metis is thread-safe, but it might be easy enough to write fprintf debugging code that makes sure the different threads are still getting openmp compatible tls variables after our patch. > Should we just notify the Metis developers? Check and see if the unmodified parmetis (which includes the metis files we upgraded to) works on Mac? They might have some hack in their build system, which I ignored and threw away. If unmodified parmetis doesn't build on Mac either, then definitely notify them. Thanks, --- Roy ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Libmesh-devel mailing list Libmesh-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-devel
