Sun Studio 12 Update 1: OpenMP API User's Guide

3.8 Environment Variables

Variable Name	Implementation
`OMP_SCHEDULE`	If the schedule type specified for the `OMP_SCHEDULE` is not one of the valid types (`static`, `dynamic`, `guided`, or `auto`), then the environment variable will be ignored, and the default schedule (`static` with no chunk size) will be used. A warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`. If the schedule type specified for the `OMP_SCHEDULE` environment variable is `static`, `dynamic`, or `guided`, but the chunk specified size is a negative integer, then the chunk size used will be as follows: For `static`, there will be no chunk size . For `dynamic` and `guided`, the chunk size will be 1. A warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`.
`OMP_NUM_THREADS`	If the value of the variable is not a positive integer, then the environment variable will be ignored and a warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`. If the value of the variable is greater than the number of threads the implementation can support, the following actions are taken: - if dynamic adjustment of the number of threads is enabled, then the number of threads will be reduced and a warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`. - if, on the other hand, dynamic adjustment of the number of threads is disabled, then an error message will be issued and the program will stop.
`OMP_DYNAMIC`	If the value specified for `OMP_DYNAMIC` is neither `TRUE` nor `FALSE`, then the value will be ignored, and the default value `TRUE` will be used. A warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`.
`OMP_NESTED`	If the value specified for `OMP_NESTED` is neither `TRUE` nor `FALSE`, then the value will be ignored, and the default value `FALSE` will be used. A warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`.
`OMP_STACKSIZE`	If the value given for `OMP_STACKSIZE` does not conform to the specified format, then the value will be ignored, and the default value (4 Megabytes for 32-bit applications, and 8 Megabytes for 64-bit applications) will be used. A warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`.
`OMP_WAIT_POLICY`	The `ACTIVE` behavior for a thread is spin. The `PASSIVE` behavior for a thread is sleep, after possibly spinning for a while.
`OMP_MAX_ACTIVE_LEVELS`	If the value specified for `OMP_MAX_ACTIVE_LEVELS` is not a nonnegative integer, then the value will be ignored, and the default value (4) will be used. A warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`.
`OMP_THREAD_LIMIT`	If the value specified for `OMP_THREAD_LIMIT` is not a positive integer, then the value will be ignored, and the default value (1024) will be used. A warning message will be issued if `SUNW_MP_WARN` is set to `TRUE` or a callback function is registered by a call to `sunw_mp_register_warn()`.