Function: mem_import_from_shareable_handle

Applicable Products

Description

Obtains the information in the shareable handle in this process and returns the handle in this process to establish the mapping between virtual addresses and physical addresses in this process. This API can also be used to generate a handle for a specified device.

This API must work with other APIs to implement memory sharing. For details, see the description of acl.rt.mem_export_to_shareable_handle.

Prototype

• C Prototype

  1	aclError aclrtMemImportFromShareableHandle(uint64_t shareableHandle, int32_t deviceId, aclrtDrvMemHandle *handle)

• Python Function

  1	handle, ret = acl.rt.mem_import_from_shareable_handle(shareable_handle, device_id)

Parameters

Return Values

Constraints

• Atlas 200I/500 A2 inference products in Ascend RC form: This API is not supported.

• Before calling this API, ensure that the physical memory to be shared exists and cannot be released in advance.
• Each handle must correspond to only one shareable handle in the same process. One-to-many or many-to-one mapping is not allowed.
• The handle can be exported by calling acl.rt.mem_export_to_shareable_handle on a device, and then the handle on another device can be generated by calling this API.
• After the memory is used, call acl.rt.free_physical to destroy the handle. The handle is destroyed only when all processes that call this API destroy the shareable handle.
• Physical memory can be shared across devices.

  Cross-device physical memory sharing supports only the following models and must be used together with the acl.rt.device_enable_peer_access API:

  Atlas A3 training products/Atlas A3 inference products

  Atlas A2 training products/Atlas A2 inference products

  Atlas training products

  Atlas inference products