OMP_ALLOCATOR (GNU libgomp)

### 4.1 `OMP_ALLOCATOR` – Set the default allocator ¶

ICV: def-allocator-var
Scope: data environment
Description:

  Sets the default allocator that is used when no allocator has been specified in the `allocate` or `allocator` clause or if an OpenMP memory routine is invoked with the `omp_null_allocator` allocator. If unset, `omp_default_mem_alloc` is used.

  The value can either be a predefined allocator or a predefined memory space or a predefined memory space followed by a colon and a comma-separated list of memory trait and value pairs, separated by `=`.

  See Memory allocation for a list of supported predefined allocators, memory spaces, and traits.

  Note: The corresponding device environment variables are currently not supported. Therefore, the non-host def-allocator-var ICVs are always initialized to `omp_default_mem_alloc`. However, on all devices, the `omp_set_default_allocator` API routine can be used to change value.

  Examples:

      OMP_ALLOCATOR=omp_high_bw_mem_alloc
      OMP_ALLOCATOR=omp_large_cap_mem_space
      OMP_ALLOCATOR=omp_low_lat_mem_space:pinned=true,partition=nearest

See also:

  Memory allocation, `omp_get_default_allocator` – Get the default allocator, `omp_set_default_allocator` – Set the default allocator, Offload-Target Specifics

Reference:

  OpenMP specification v5.0, Section 6.21