Class DriverAPINativeMethods.CudaPeerAccess

Peer Context Memory Access

Inheritance

System.Object

DriverAPINativeMethods.CudaPeerAccess

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: ManagedCuda

Assembly: ManagedCuda.dll

Syntax

public static class CudaPeerAccess

Methods

cuCtxDisablePeerAccess(CUcontext)

Disables direct access to memory allocations in a peer context and unregisters any registered allocations.

Declaration

public static CUResult cuCtxDisablePeerAccess(CUcontext peerContext)

Parameters

Type	Name	Description
CUcontext	peerContext	Peer context to disable direct access to

Returns

Type	Description
CUResult	CUDA Error Codes: Success, ErrorDeinitialized, ErrorNotInitialized, ErrorPeerAccessNotEnabled, ErrorInvalidContext. Note that this function may also return error codes from previous, asynchronous launches.

cuCtxEnablePeerAccess(CUcontext, CtxEnablePeerAccessFlags)

If both the current context and peerContext are on devices which support unified addressing (as may be queried using ::CU_DEVICE_ATTRIBUTE_UNIFIED_ADDRESSING), then on success all allocations from peerContext will immediately be accessible by the current context. See \ref CUDA_UNIFIED for additional details.

Note that access granted by this call is unidirectional and that in order to access memory from the current context in peerContext, a separate symmetric call to ::cuCtxEnablePeerAccess() is required.

Returns ErrorInvalidDevice if cuDeviceCanAccessPeer(ref Int32, CUdevice, CUdevice) indicates that the CUdevice of the current context cannot directly access memory from the CUdevice of peerContext.

Returns ErrorPeerAccessAlreadyEnabled if direct access of peerContext from the current context has already been enabled.

Returns ErrorInvalidContext if there is no current context, peerContext is not a valid context, or if the current context is peerContext.

Returns ErrorInvalidValue if Flags is not 0.

Declaration

public static CUResult cuCtxEnablePeerAccess(CUcontext peerContext, CtxEnablePeerAccessFlags Flags)

Parameters

Type	Name	Description
CUcontext	peerContext	Peer context to enable direct access to from the current context
CtxEnablePeerAccessFlags	Flags	Reserved for future use and must be set to 0

Returns

Type	Description
CUResult	CUDA Error Codes: Success, ErrorDeinitialized, ErrorNotInitialized, ErrorInvalidDevice, ErrorPeerAccessAlreadyEnabled, ErrorInvalidContext, ErrorInvalidValue. Note that this function may also return error codes from previous, asynchronous launches.

cuDeviceCanAccessPeer(ref Int32, CUdevice, CUdevice)

Returns in canAccessPeer a value of 1 if contexts on dev are capable of directly accessing memory from contexts on peerDev and 0 otherwise. If direct access of peerDev from dev is possible, then access may be enabled on two specific contexts by calling cuCtxEnablePeerAccess(CUcontext, CtxEnablePeerAccessFlags).

Declaration

public static CUResult cuDeviceCanAccessPeer(ref int canAccessPeer, CUdevice dev, CUdevice peerDev)

Parameters

Type	Name	Description
System.Int32	canAccessPeer	Returned access capability
CUdevice	dev	Device from which allocations on peerDev are to be directly accessed.
CUdevice	peerDev	Device on which the allocations to be directly accessed by dev reside.

Returns

Type	Description
CUResult	CUDA Error Codes: Success, ErrorDeinitialized, ErrorNotInitialized, ErrorInvalidDevice. Note that this function may also return error codes from previous, asynchronous launches.

cuDeviceGetP2PAttribute(ref Int32, CUdevice_P2PAttribute, CUdevice, CUdevice)

Queries attributes of the link between two devices.

Returns in \p *value the value of the requested attribute \p attrib of the link between \p srcDevice and \p dstDevice. The supported attributes are:

• ::CU_DEVICE_P2P_ATTRIBUTE_PERFORMANCE_RANK: A relative value indicating the performance of the link between two devices.

• ::CU_DEVICE_P2P_ATTRIBUTE_ACCESS_SUPPORTED P2P: 1 if P2P Access is enable.

• ::CU_DEVICE_P2P_ATTRIBUTE_NATIVE_ATOMIC_SUPPORTED: 1 if Atomic operations over the link are supported.

Declaration

public static CUResult cuDeviceGetP2PAttribute(ref int value, CUdevice_P2PAttribute attrib, CUdevice srcDevice, CUdevice dstDevice)

Parameters

Type	Name	Description
System.Int32	value	Returned value of the requested attribute
CUdevice_P2PAttribute	attrib	The requested attribute of the link between \p srcDevice and \p dstDevice.
CUdevice	srcDevice	The source device of the target link.
CUdevice	dstDevice	The destination device of the target link.

Returns

Type	Description
CUResult