* Convert from AC_TRY_RUN to AC_RUN_IFELSE.
* Excellent suggestion from Paul Hargrove: use AC_CHECK_FUNC to look
for a Linuxthreads-specific symbol when we're cross compiling to
see if threads will have different PIDs (because AC_CHECK_FUNC
works properly even when in cross-compiling environments).
Background: the old/Linuxthreads-based pthreads implementation used
the Linux clone() call to make threads, which effectively meant that
each thread had a different PID. The new NPTL pthreads implementation
does things better, meaning that threads have the same PID.
Open MPI no longer supports threads with different PIDs -- we ripped
out the supporting code for threads with different PIDs because we
don't have systems available to test this on anymore (anyone who still
has such a system can still use older versions of Open MPI). Hence,
configure needs to determine whether the target system will have the
same PID for threads or not -- even if we're cross-compiling. The
current test compiles and runs a multi-threaded app that checks PIDs
of different threads, but we clearly can't do that in a
cross-compiling environment. So use AC_CHECK_FUNC in cross-compiling
environments.
Simple, no?
This commit was SVN r24537.
There was no compelling reason to support such old kernels. Accordingly, convert the test to print a nice error message indicating we no longer support old kernels (but indicate that earlier OMPI versions do) and error out. Remove all code that was protected by "if have different pids" since it can no longer be compiled.
This commit was SVN r24531.
Continue the reorganization of the configure system. Move files from the main config directory to their appropriate level-specific config directories. Modify the configure system to correctly handle compiler detection, test, and setup so that all things pertaining to opal and orte are done at the lower level, with the ompi configure system only looking at mpi-specific options.
Ensure the wrapper compilers for orte and ompi only get built when appropriate. Add support for c++ to the orte wrapper compilers, both script and non-script versions.
This commit was SVN r22138.
