aclrtMemP2PMap

Applicability

Product	Supported
Atlas 350 Accelerator Card	√
Atlas A3 training product/Atlas A3 inference product	√
Atlas A2 training product/Atlas A2 inference product	√
Atlas 200I/500 A2 inference product	☓
Atlas inference product	√
Atlas training product	√

Function

Establishes a memory page table mapping between two devices in the same process to implement cross-device memory access. However, before performing this operation, you need to call aclrtDeviceEnablePeerAccess to enable data exchange between the two devices.

After this API is called to establish page table mapping, memory page faults will not occur during cross-device access, and the performance is better when the memory is accessed for the first time.

Prototype

aclError aclrtMemP2PMap(void *devPtr, size_t size, int32_t dstDevId, uint64_t flags)

Parameters

Parameter	Input/Output	Description
devPtr	Input	Device memory address (for example, the device memory allocated by calling aclrtMalloc). Here, it refers to the memory address of the shared memory provider.
size	Input	Memory size, in bytes
dstDevId	Input	Device ID, which indicates the ID of the shared memory user.
flags	Input	Reserved. The value is fixed at 0.

Returns

0 on success; else, failure. For details, see aclError.

Parent topic: Memory Management