aclrtGetDevicesTopo

Applicable Products

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

Note: This API cannot be called for the Atlas 200I/500 A2 inference products in Ascend RC form.

Function

Obtains the network topology between two devices.

Prototype

aclError aclrtGetDevicesTopo(uint32_t deviceId, uint32_t otherDeviceId, uint64_t *value)

Parameters

Parameter	Input/Output	Description
deviceId	Input	Device ID. The value must be in the range of [0, (Available device count – 1)]. Call aclrtGetDeviceCount to obtain the device count.
otherDeviceId	Input	Device ID. The value must be in the range of [0, (Available device count – 1)]. Call aclrtGetDeviceCount to obtain the device count.
value	Output	Topology between two devices. ACL_RT_DEVS_TOPOLOGY_HCCS: connected through HCCS. Huawei Cache Coherence System (HCCS) is used for high-speed interconnection across CPUs and NPUs. ACL_RT_DEVS_TOPOLOGY_PIX: connected through the same PCIe switch. ACL_RT_DEVS_TOPOLOGY_PHB: connected through the PCIe host bridge. ACL_RT_DEVS_TOPOLOGY_SYS: connected through Symmetric Multiprocessing (SMP). NUMA nodes are interconnected through SMP. ACL_RT_DEVS_TOPOLOGY_SIO: intra-chip connection. Two dies are connected through this mode. ACL_RT_DEVS_TOPOLOGY_HCCS_SW: connected through the HCCS switch. ACL_RT_DEVS_TOPOLOGY_PIB: reserved value, not supported currently. The macros are defined as follows: #define ACL_RT_DEVS_TOPOLOGY_HCCS 0x01ULL #define ACL_RT_DEVS_TOPOLOGY_PIX 0x02ULL #define ACL_RT_DEVS_TOPOLOGY_PHB 0x08ULL #define ACL_RT_DEVS_TOPOLOGY_SYS 0x10ULL #define ACL_RT_DEVS_TOPOLOGY_SIO 0x20ULL #define ACL_RT_DEVS_TOPOLOGY_HCCS_SW 0x40ULL #define ACL_RT_DEVS_TOPOLOGY_PIB 0x04ULL

Parameter

Input/Output

Description

deviceId

Input

Device ID.

The value must be in the range of [0, (Available device count – 1)]. Call aclrtGetDeviceCount to obtain the device count.

otherDeviceId

Input

Device ID.

The value must be in the range of [0, (Available device count – 1)]. Call aclrtGetDeviceCount to obtain the device count.

value

Output

Topology between two devices.

ACL_RT_DEVS_TOPOLOGY_HCCS: connected through HCCS. Huawei Cache Coherence System (HCCS) is used for high-speed interconnection across CPUs and NPUs.
ACL_RT_DEVS_TOPOLOGY_PIX: connected through the same PCIe switch.
ACL_RT_DEVS_TOPOLOGY_PHB: connected through the PCIe host bridge.
ACL_RT_DEVS_TOPOLOGY_SYS: connected through Symmetric Multiprocessing (SMP). NUMA nodes are interconnected through SMP.
ACL_RT_DEVS_TOPOLOGY_SIO: intra-chip connection. Two dies are connected through this mode.
ACL_RT_DEVS_TOPOLOGY_HCCS_SW: connected through the HCCS switch.
ACL_RT_DEVS_TOPOLOGY_PIB: reserved value, not supported currently.

The macros are defined as follows:

#define ACL_RT_DEVS_TOPOLOGY_HCCS     0x01ULL
#define ACL_RT_DEVS_TOPOLOGY_PIX      0x02ULL
#define ACL_RT_DEVS_TOPOLOGY_PHB      0x08ULL
#define ACL_RT_DEVS_TOPOLOGY_SYS      0x10ULL
#define ACL_RT_DEVS_TOPOLOGY_SIO      0x20ULL
#define ACL_RT_DEVS_TOPOLOGY_HCCS_SW  0x40ULL
#define ACL_RT_DEVS_TOPOLOGY_PIB      0x04ULL

Returns

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

Parent topic: Device Management