Functions

nvmlReturn_t nvmlDeviceFreezeNvLinkUtilizationCounter ( nvmlDevice_t device, unsigned int  link, unsigned int  counter, nvmlEnableState_t freeze )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

counter

Specifies the counter that should be frozen (0 or 1).

freeze

NVML_FEATURE_ENABLED = freeze the receive and transmit counters NVML_FEATURE_DISABLED = unfreeze the receive and transmit counters

Returns

• NVML_SUCCESS if counters were successfully frozen or unfrozen
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device, link, counter, or freeze is invalid
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Deprecated: Freezing NVLINK utilization counters is no longer supported.

Freeze the NVLINK utilization counters Both the receive and transmit counters are operated on by this function

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvLinkCapability ( nvmlDevice_t device, unsigned int  link, nvmlNvLinkCapability_t capability, unsigned int* capResult )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

capability

Specifies the nvmlNvLinkCapability_t to be queried

capResult

A boolean for the queried capability indicating that feature is available

Returns

• NVML_SUCCESS if capResult has been set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device, link, or capability is invalid or capResult is NULL
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Retrieves the requested capability from the device's NvLink for the link specified Please refer to the nvmlNvLinkCapability_t structure for the specific caps that can be queried The return value should be treated as a boolean.

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvLinkErrorCounter ( nvmlDevice_t device, unsigned int  link, nvmlNvLinkErrorCounter_t counter, unsigned long long* counterValue )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

counter

Specifies the NvLink counter to be queried

counterValue

Returned counter value

Returns

• NVML_SUCCESS if counter has been set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device, link, or counter is invalid or counterValue is NULL
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Retrieves the specified error counter value Please refer to nvmlNvLinkErrorCounter_t for error counters that are available

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvLinkRemoteDeviceType ( nvmlDevice_t device, unsigned int  link, nvmlIntNvLinkDeviceType_t* pNvLinkDeviceType )

Parameters

device

The device handle of the target GPU

link

The NVLink link index on the target GPU

pNvLinkDeviceType

Pointer in which the output remote device type is returned

Returns

• NVML_SUCCESS if pNvLinkDeviceType has been set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_NOT_SUPPORTED if NVLink is not supported
• NVML_ERROR_INVALID_ARGUMENT if device or link is invalid, or pNvLinkDeviceType is NULL
• NVML_ERROR_GPU_IS_LOST if the target GPU has fallen off the bus or is otherwise inaccessible
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Get the NVLink device type of the remote device connected over the given link.

nvmlReturn_t nvmlDeviceGetNvLinkRemotePciInfo_v2 ( nvmlDevice_t device, unsigned int  link, nvmlPciInfo_t* pci )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

pci

nvmlPciInfo_t of the remote node for the specified link

Returns

• NVML_SUCCESS if pci has been set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device or link is invalid or pci is NULL
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Retrieves the PCI information for the remote node on a NvLink link Note: pciSubSystemId is not filled in this function and is indeterminate

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvLinkState ( nvmlDevice_t device, unsigned int  link, nvmlEnableState_t* isActive )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

isActive

nvmlEnableState_t where NVML_FEATURE_ENABLED indicates that the link is active and NVML_FEATURE_DISABLED indicates it is inactive

Returns

• NVML_SUCCESS if isActive has been set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device or link is invalid or isActive is NULL
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Retrieves the state of the device's NvLink for the link specified

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvLinkUtilizationControl ( nvmlDevice_t device, unsigned int  link, unsigned int  counter, nvmlNvLinkUtilizationControl_t* control )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

counter

Specifies the counter that should be set (0 or 1).

control

A reference to the nvmlNvLinkUtilizationControl_t to place information

Returns

• NVML_SUCCESS if the control has been set successfully
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device, counter, link, or control is invalid
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Deprecated: Getting utilization counter control is no longer supported.

Get the NVLINK utilization counter control information for the specified counter, 0 or 1. Please refer to nvmlNvLinkUtilizationControl_t for the structure definition

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvLinkUtilizationCounter ( nvmlDevice_t device, unsigned int  link, unsigned int  counter, unsigned long long* rxcounter, unsigned long long* txcounter )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

counter

Specifies the counter that should be read (0 or 1).

rxcounter

Receive counter return value

txcounter

Transmit counter return value

Returns

• NVML_SUCCESS if rxcounter and txcounter have been successfully set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device, counter, or link is invalid or rxcounter or txcounter are NULL
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Deprecated: Use nvmlDeviceGetFieldValues with NVML_FI_DEV_NVLINK_THROUGHPUT_* as field values instead.

Retrieve the NVLINK utilization counter based on the current control for a specified counter. In general it is good practice to use nvmlDeviceSetNvLinkUtilizationControl before reading the utilization counters as they have no default state

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvLinkVersion ( nvmlDevice_t device, unsigned int  link, unsigned int* version )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

version

Requested NvLink version from nvmlNvlinkVersion_t

Returns

• NVML_SUCCESS if version has been set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device or link is invalid or version is NULL
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Retrieves the version of the device's NvLink for the link specified

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceGetNvlinkBwMode ( nvmlDevice_t device, nvmlNvlinkGetBwMode_t* getBwMode )

Parameters

device

The identifier of the target device

getBwMode

Reference to nvmlNvlinkGetBwMode_t

Returns

• NVML_SUCCESS if the query was successful
• NVML_ERROR_INVALID_ARGUMENT if device is invalid or getBwMode is NULL
• NVML_ERROR_NOT_SUPPORTED if this feature is not supported by the device
• NVML_ERROR_ARGUMENT_VERSION_MISMATCH if the version specified is not supported

Description

Get the NvLink Reduced Bandwidth Mode for the device

BLACKWELL_OR_NEWER%

nvmlReturn_t nvmlDeviceGetNvlinkSupportedBwModes ( nvmlDevice_t device, nvmlNvlinkSupportedBwModes_t* supportedBwMode )

Parameters

device

The identifier of the target device

supportedBwMode

Reference to nvmlNvlinkSupportedBwModes_t

Returns

• NVML_SUCCESS if the query was successful
• NVML_ERROR_INVALID_ARGUMENT if device is invalid or supportedBwMode is NULL
• NVML_ERROR_NOT_SUPPORTED if this feature is not supported by the device
• NVML_ERROR_ARGUMENT_VERSION_MISMATCH if the version specified is not supported

Description

Get the supported NvLink Reduced Bandwidth Modes of the device

BLACKWELL_OR_NEWER%

nvmlReturn_t nvmlDeviceResetNvLinkErrorCounters ( nvmlDevice_t device, unsigned int  link )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

Returns

• NVML_SUCCESS if the reset is successful
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device or link is invalid
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Resets all error counters to zero Please refer to nvmlNvLinkErrorCounter_t for the list of error counters that are reset

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceResetNvLinkUtilizationCounter ( nvmlDevice_t device, unsigned int  link, unsigned int  counter )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be reset

counter

Specifies the counter that should be reset (0 or 1)

Returns

• NVML_SUCCESS if counters were successfully reset
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device, link, or counter is invalid
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Deprecated: Resetting NVLINK utilization counters is no longer supported.

Reset the NVLINK utilization counters Both the receive and transmit counters are operated on by this function

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceSetNvLinkDeviceLowPowerThreshold ( nvmlDevice_t device, nvmlNvLinkPowerThres_t* info )

Parameters

device

The identifier of the target device

info

Reference to nvmlNvLinkPowerThres_t struct input parameters

Returns

• NVML_SUCCESS if the Threshold is successfully set
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device is invalid or Threshold is not within range
• NVML_ERROR_NOT_READY if an internal driver setting prevents the threshold from being used
• NVML_ERROR_NOT_SUPPORTED if this query is not supported by the device

Description

Set NvLink Low Power Threshold for device.

For Hopper or newer fully supported devices.

nvmlReturn_t nvmlDeviceSetNvLinkUtilizationControl ( nvmlDevice_t device, unsigned int  link, unsigned int  counter, nvmlNvLinkUtilizationControl_t* control, unsigned int  reset )

Parameters

device

The identifier of the target device

link

Specifies the NvLink link to be queried

counter

Specifies the counter that should be set (0 or 1).

control

A reference to the nvmlNvLinkUtilizationControl_t to set

reset

Resets the counters on set if non-zero

Returns

• NVML_SUCCESS if the control has been set successfully
• NVML_ERROR_UNINITIALIZED if the library has not been successfully initialized
• NVML_ERROR_INVALID_ARGUMENT if device, counter, link, or control is invalid
• NVML_ERROR_NOT_SUPPORTED if the device doesn't support this feature
• NVML_ERROR_UNKNOWN on any unexpected error

Description

Deprecated: Setting utilization counter control is no longer supported.

Set the NVLINK utilization counter control information for the specified counter, 0 or 1. Please refer to nvmlNvLinkUtilizationControl_t for the structure definition. Performs a reset of the counters if the reset parameter is non-zero.

For Pascal or newer fully supported devices.

nvmlReturn_t nvmlDeviceSetNvlinkBwMode ( nvmlDevice_t device, nvmlNvlinkSetBwMode_t* setBwMode )

Parameters

device

The identifier of the target device

setBwMode

Reference to nvmlNvlinkSetBwMode_t

Returns

• NVML_SUCCESS if the Bandwidth mode was successfully set
• NVML_ERROR_INVALID_ARGUMENT if device is invalid or setBwMode is NULL
• NVML_ERROR_NO_PERMISSION if user does not have permission to change Bandwidth mode
• NVML_ERROR_NOT_SUPPORTED if this feature is not supported by the device
• NVML_ERROR_ARGUMENT_VERSION_MISMATCH if the version specified is not supported

Description

Set the NvLink Reduced Bandwidth Mode for the device

BLACKWELL_OR_NEWER%

nvmlReturn_t nvmlSystemGetNvlinkBwMode ( unsigned int* nvlinkBwMode )

Parameters

nvlinkBwMode

reference of nvlink bandwidth mode

Returns

• NVML_SUCCESS on success
• NVML_ERROR_INVALID_ARGUMENT if an invalid pointer is provided
• NVML_ERROR_NOT_SUPPORTED if GPU is not Hopper or newer architecture.
• NVML_ERROR_NO_PERMISSION if not root user

Description

Get the global nvlink bandwith mode

nvmlReturn_t nvmlSystemSetNvlinkBwMode ( unsigned int  nvlinkBwMode )

Parameters

nvlinkBwMode

nvlink bandwidth mode

Returns

• NVML_SUCCESS on success
• NVML_ERROR_INVALID_ARGUMENT if an invalid argument is provided
• NVML_ERROR_IN_USE if P2P object exists
• NVML_ERROR_NOT_SUPPORTED if GPU is not Hopper or newer architecture.
• NVML_ERROR_NO_PERMISSION if not root user

Description

Set the global nvlink bandwith mode