PeerToPeer Device Memory Access

Macros | Functions

PeerToPeer Device Memory Access

HIP API

Collaboration diagram for PeerToPeer Device Memory Access:

Macros
#define	USE_PEER_NON_UNIFIED   1

Functions
hipError_t	hipDeviceCanAccessPeer (int *canAccessPeer, int deviceId, int peerDeviceId)
	Determine if a device can access a peer's memory. More...
hipError_t	hipDeviceEnablePeerAccess (int peerDeviceId, unsigned int flags)
	Enable direct access from current device's virtual address space to memory allocations physically located on a peer device. More...
hipError_t	hipDeviceDisablePeerAccess (int peerDeviceId)
	Disable direct access from current device's virtual address space to memory allocations physically located on a peer device. More...
hipError_t	hipMemGetAddressRange (hipDeviceptr_t *pbase, size_t *psize, hipDeviceptr_t dptr)
	Get information on memory allocations. More...
hipError_t	hipMemcpyPeer (void *dst, int dstDeviceId, const void *src, int srcDeviceId, size_t sizeBytes)
	Copies memory from one device to memory on another device. More...
hipError_t	hipMemcpyPeerAsync (void *dst, int dstDeviceId, const void *src, int srcDevice, size_t sizeBytes, hipStream_t stream)
	Copies memory from one device to memory on another device. More...

Detailed Description

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Warning

PeerToPeer support is experimental. This section describes the PeerToPeer device memory access functions of HIP runtime API.

Macro Definition Documentation

◆ USE_PEER_NON_UNIFIED

#define USE_PEER_NON_UNIFIED   1

Function Documentation

◆ hipDeviceCanAccessPeer()

hipError_t hipDeviceCanAccessPeer	(	int *	canAccessPeer,
		int	deviceId,
		int	peerDeviceId
	)

Determine if a device can access a peer's memory.

Parameters

[out]	canAccessPeer	Returns the peer access capability (0 or 1)
[in]	deviceId	- device from where memory may be accessed.
[in]	peerDeviceId	- device where memory is physically located

Returns "1" in canAccessPeer if the specified device is capable of directly accessing memory physically located on peerDevice , or "0" if not.

Returns "0" in canAccessPeer if deviceId == peerDeviceId, and both are valid devices : a device is not a peer of itself.

Returns

hipSuccess,

hipErrorInvalidDevice if deviceId or peerDeviceId are not valid devices

◆ hipDeviceDisablePeerAccess()

hipError_t hipDeviceDisablePeerAccess

(

int

peerDeviceId

)

Disable direct access from current device's virtual address space to memory allocations physically located on a peer device.

Returns hipErrorPeerAccessNotEnabled if direct access to memory on peerDevice has not yet been enabled from the current device.

Parameters

[in]

peerDeviceId

Peer device to disable direct access to

Returns

hipSuccess, hipErrorPeerAccessNotEnabled

◆ hipDeviceEnablePeerAccess()

hipError_t hipDeviceEnablePeerAccess	(	int	peerDeviceId,
		unsigned int	flags
	)

Enable direct access from current device's virtual address space to memory allocations physically located on a peer device.

Memory which already allocated on peer device will be mapped into the address space of the current device. In addition, all future memory allocations on peerDeviceId will be mapped into the address space of the current device when the memory is allocated. The peer memory remains accessible from the current device until a call to hipDeviceDisablePeerAccess or hipDeviceReset.

Parameters

[in]	peerDeviceId	Peer device to enable direct access to from the current device
[in]	flags	Reserved for future use, must be zero

Returns hipSuccess, hipErrorInvalidDevice, hipErrorInvalidValue,

Returns

hipErrorPeerAccessAlreadyEnabled if peer access is already enabled for this device.

◆ hipMemcpyPeer()

hipError_t hipMemcpyPeer	(	void *	dst,
		int	dstDeviceId,
		const void *	src,
		int	srcDeviceId,
		size_t	sizeBytes
	)

Copies memory from one device to memory on another device.

Parameters

[out]	dst	- Destination device pointer.
[in]	dstDeviceId	- Destination device
[in]	src	- Source device pointer
[in]	srcDeviceId	- Source device
[in]	sizeBytes	- Size of memory copy in bytes

Returns

hipSuccess, hipErrorInvalidValue, hipErrorInvalidDevice

◆ hipMemcpyPeerAsync()

hipError_t hipMemcpyPeerAsync	(	void *	dst,
		int	dstDeviceId,
		const void *	src,
		int	srcDevice,
		size_t	sizeBytes,
		hipStream_t	stream
	)

Copies memory from one device to memory on another device.

Parameters

[out]	dst	- Destination device pointer.
[in]	dstDeviceId	- Destination device
[in]	src	- Source device pointer
[in]	srcDevice	- Source device
[in]	sizeBytes	- Size of memory copy in bytes
[in]	stream	- Stream identifier

Returns

hipSuccess, hipErrorInvalidValue, hipErrorInvalidDevice

◆ hipMemGetAddressRange()

hipError_t hipMemGetAddressRange	(	hipDeviceptr_t *	pbase,
		size_t *	psize,
		hipDeviceptr_t	dptr
	)

Get information on memory allocations.

Parameters

[out]	pbase	- BAse pointer address
[out]	psize	- Size of allocation
[in]	dptr-	Device Pointer

Returns

hipSuccess, hipErrorNotFound

See also

hipCtxCreate, hipCtxDestroy, hipCtxGetFlags, hipCtxPopCurrent, hipCtxGetCurrent, hipCtxSetCurrent, hipCtxPushCurrent, hipCtxSetCacheConfig, hipCtxSynchronize, hipCtxGetDevice