baa8ddb6___Compiling___Running_Programs__Description
[Environment Variable] XLSMPORTS=stack=n (SMP stack size (default = 4 MB/thread)) [Description] 
Sets a thread's run-time stack size, where n is in bytes. Remember, that for 32-bit applications the total stack size for all threads in a process cannot exceed 256 MB. This limitation does not apply to 64-bit applications.
TAMU Supercomputing Facility -- Hydra User Guide: Compiling & Running Programs
Description