GNU libgomp: OMP_PROC_BIND

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### 3.9 `OMP_PROC_BIND` – Whether theads may be moved between CPUs

Description:

  Specifies whether threads may be moved between processors. If set to `TRUE`, OpenMP theads should not be moved; if set to `FALSE` they may be moved. Alternatively, a comma separated list with the values `MASTER`, `CLOSE` and `SPREAD` can be used to specify the thread affinity policy for the corresponding nesting level. With `MASTER` the worker threads are in the same place partition as the master thread. With `CLOSE` those are kept close to the master thread in contiguous place partitions. And with `SPREAD` a sparse distribution across the place partitions is used.

  When undefined, `OMP_PROC_BIND` defaults to `TRUE` when `OMP_PLACES` or `GOMP_CPU_AFFINITY` is set and `FALSE` otherwise.

See also:

  OMP_PLACES, GOMP_CPU_AFFINITY, omp_get_proc_bind

Reference:

  OpenMP specification v4.5, Section 4.4