Product	Supported (√/x)
Ascend 950PR/Ascend 950DT	√
Atlas A3 training products/Atlas A3 inference products	√
Atlas A2 training products/Atlas A2 inference products	√
Atlas training products	√
Atlas inference products	√
Atlas 200I/500 A2 inference products	x

Queries whether memory copy is supported between two devices.

C Prototype

aclError aclrtDeviceCanAccessPeer(int32_t *canAccessPeer, int32_t deviceId, int32_t peerDeviceId)

Python Function

can_access_peer, ret = acl.rt.device_can_access_peer(dev_id, peer_dev_id)

Parameter	Description
dev_id	Int, specified device ID, which must be different from that of peer_dev_id. Must be in the range of [0, Device count – 1]. Call acl.rt.get_device_count to obtain the device count.
peer_dev_id	Int, specified device ID, which must be different from that of dev_id. Must be in the range of [0, Device count – 1]. Call acl.rt.get_device_count to obtain the device count.

Parameter

Description

dev_id

Int, specified device ID, which must be different from that of peer_dev_id.

Must be in the range of [0, Device count – 1]. Call acl.rt.get_device_count to obtain the device count.

peer_dev_id

Int, specified device ID, which must be different from that of dev_id.

Must be in the range of [0, Device count – 1]. Call acl.rt.get_device_count to obtain the device count.

Return Value	Description
can_access_peer	Int, whether memory copy is supported between the device specified by dev_id and the device specified by peer_dev_id. 1: supported; 0: not supported.
ret	Int, error code. 0 on success; else, failure.

This API supports memory copy only in physical machines and containers.
This API supports memory copy only between devices in the same PCIe switch. In AI Server applications, memory copy between devices is supported although they reside in different PCIe switches.
This API supports memory copy only between devices in the same physical machine or container.
This API supports memory copy only between devices of threads in the same process.
This API supports memory copy between devices in the same PCIe switch only when the related ports of the host are enabled (such as the host BIOS).
This API is not supported by the Atlas 500 Pro (model 3000).

Function: device_can_access_peer