MPI

Collaboration diagram for MPI:

Classes
class	MpiNode
class	MpiTaskDistributor
class	MpiFileMutex
class	XmippMpiProgram
class	MpiMetadataProgram
class	BasicMpiMetadataProgram< BASE_CLASS >

Macros
#define	TAG_WORK   0
#define	TAG_STOP   1
#define	TAG_WAIT   2
#define	TAG_WORK_REQUEST   100
#define	TAG_WORK_RESPONSE   101

Functions
void	xmipp_MPI_Reduce (void *send_data, void *recv_data, size_t count, MPI_Datatype datatype, MPI_Op op, int root, MPI_Comm communicator, size_t blockSize=1048576)

Detailed Description

Macro Definition Documentation

TAG_STOP

#define TAG_STOP   1

Definition at line 79 of file xmipp_mpi.h.

TAG_WAIT

#define TAG_WAIT   2

Definition at line 80 of file xmipp_mpi.h.

TAG_WORK

#define TAG_WORK   0

Definition at line 78 of file xmipp_mpi.h.

TAG_WORK_REQUEST

#define TAG_WORK_REQUEST   100

Definition at line 82 of file xmipp_mpi.h.

TAG_WORK_RESPONSE

#define TAG_WORK_RESPONSE   101

Definition at line 83 of file xmipp_mpi.h.

Function Documentation

xmipp_MPI_Reduce()

void xmipp_MPI_Reduce	(	void *	send_data,
		void *	recv_data,
		size_t	count,
		MPI_Datatype	datatype,
		MPI_Op	op,
		int	root,
		MPI_Comm	communicator,
		size_t	blockSize = 1048576
	)

MPI Reduce with memory constraint. MPI_Reduce may give a segmentation fault when sharing large objects

Definition at line 331 of file xmipp_mpi.cpp.

{
    int type_size;
    MPI_Type_size(datatype,&type_size);
    size_t quotient=count/blockSize;
    if (quotient>0)
    {
        for (size_t c=0; c<quotient; c++)
            MPI_Reduce((unsigned char*)(send_data)+c*blockSize*size_t(type_size),
                       (unsigned char*)(recv_data)+c*blockSize*size_t(type_size),
                       blockSize,datatype,op,root,communicator);
    }
    size_t remainder=count%blockSize;
    if (remainder>0)
        MPI_Reduce((unsigned char*)(send_data)+quotient*blockSize*size_t(type_size),
                   (unsigned char*)(recv_data)+quotient*blockSize*size_t(type_size),
                   remainder,datatype,op,root,communicator);
}