ND_SGE Structure

Represents local memory segments used in Send, Receive, Read, and Write requests.

typedef struct _ND_SGE {
  VOID         *vAddr;
  SIZE_T       Length;
  ND_MR_HANDLE hMr;
} ND_SGE, *PND_SGE;

vAddr
The address of the buffer. The buffer is located within registered memory if hMr is not NULL; otherwise, if NULL, the memory could be defined inside or outside the registered memory.
Length
The size, in bytes, of the buffer.
hMr
Handle to the registered memory where the data is located. The handle allows the hardware direct access to the memory because the hardware mapped the memory when you registered it.

Set to NULL if you are using the vAddr buffer as an inline buffer (the data is included in the entry and is not mapped). If the data is small (typically 128 bytes or less although some hardware supports infinite inline data), you can get better performance (lower latency) if you include the data directly in the buffer that the hardware reads to determine the requested operation (you eliminate the extra DMA operation of mapping the application payload).

Product	Microsoft Message Passing Interface (MS-MPI)
Header	Ndspi.h

Additional resources