baa8ddb6___Compiling___Running_Programs__Description
[Environment Variable] YIELDLOOPTIME=n (default = 0) [Description] 
Used only when SPINLOOPTIME is also set. It sets the number of times that the system yields a processor when trying to acquire a busy spin lock before going to sleep. The processor is yielded to another kernel thread, if one is available.
TAMU Supercomputing Facility -- Hydra User Guide: Compiling & Running Programs
Description