Local memory allocation mode

At the moment this is supported on Windows only.

In Level Zero, the API function to allocate a device (local) memory is zeMemAllocDevice. For such (device USM) allocations, there are two policies of handling the scenario enough resources being available:

• Local-preferred mode: A region is primarily allocated out of local-memory resources, however system-memory may be used as a fallback.
• Local-only mode: A can only be allocated out of local-memory resources. If the amount of available local-memory is not sufficient the ZE_RESULT_ERROR_OUT_OF_DEVICE_MEMORY error is returned.

Depending on the hardware, one of these two modes is being used by default or a specific one can be enforced by setting an environment variable NEO_LOCAL_MEMORY_ALLOCATION_MODE to respective value:

• NEO_LOCAL_MEMORY_ALLOCATION_MODE=0: HW-default (value of the flag when it is not set)
• NEO_LOCAL_MEMORY_ALLOCATION_MODE=1: Local-only
• NEO_LOCAL_MEMORY_ALLOCATION_MODE=2: Local-preferred