2002 2 2002 4 23 : MPI MPI 1 MPI MPI(Message Passing Interface) MPI UNIX Windows Machintosh OS, MPI 2 1 1 2 2.1 1 1 1 1 1 1 Fig. 1 A B C F Fig. 2 A B F Fig. 1 1 1 Fig. 2 2.2 Fig. 3 1
. Fig. 4 Fig. 3 Fig. 4. MPI 3 MPI MPI MPIF(MPI Forum) API(Application Program Interface) MPI MPI_Send MPI MPI 3.1 MPI MPI API TCP/IP MPI 3.2 MPI MPI 1. 2. 3. 4. PVM 2
3.3 MPI MPI MPICH 3.3.1 MPICH MPICH 4 MPI Programming MPI. 4.1 MPI Table 1. Table 1 MPI Init() MPI Comm size() MPI Comm rank() MPI Finalize() MPI - - rank MPI MPI MPI COMM WORLD rank : ID 0 MPI Fig. 5 4.2.,... rank0 rank1 0,. Table 2. Table 2 rank0 Data rank1 rank1 rank1 rank0 Data rank0 3
/* (1) */ #include "mpi.h" int main(int argc, char **argv) { int numprocs, myid; /* (2) MPI */ MPI_Init(&argc,&argv); /* (3) numprocs */ MPI_Comm_size(MPI_COMM_WORLD,&numprocs); /* (4) rank myid rank */ MPI_Comm_rank(MPI_COMM_WORLD,&myid); /* (5) */ } /* (6) MPI */ MPI_Finalize(); return 0; Fig. 5 MPI. MPI.. 4.3 MPICH 4.3.1 MPI. MPICH. SSH Secure SHell.. MPI FTP Sun NFS Network File System Fig. 6 /home Fig. 6 NFS 4
4.4 MPICH,,. UNIX rsh MPI. MPI mpirun., MPI., machines.linux. Fig. 7 Fig. 7 MPI MPI, ID,.,, IF,. ID MPI,,. 5 MPICH 5.1 C MPI C mpicc. MPI C MPI..,. bash$ mpicc samplecpi.c -o samplecpi 5.2 MPI,. bash$ mpirun -np 8 samplecpi -np,.., samplecpi.,,., rsh Remote SHell,. MPICH,. MPI-2. 5
6 MPICH 6.1 MPI MPI SIMD.,,. MPI MPI COMM WORLD., MPI COMM RANK. 1,., MPI Comm rank,, if(rank == 0){ // }., Fig. 8. if(myrank==0){ } if(myrank==1){ } Fig. 8 6.2,.,.MPI,.,,,.,n,,0,1,2, n-1. 6.3,. 1.,.,,. 2.,. 3.,.1) tag.2)communicator. 6.4 MPI MPI 127. 1 1,,,,,.,. 6.4.1 1 1 1 1 2 MPI SEND(buffer,count,datatype, destination,tag,communicator) 6
void *bufin int count (IN) MPI Datatype datatype (IN) int dest (IN) int tag (IN) MPI Comm comm (IN) MPI RECV(buffer,count,datatype,source, tag,communicator,status) void *buf(out) int sourcempi ANY SOURCE (IN) int tagmpi ANY TAG (IN) MPI Status *status (OUT), MPI ANY SOURCE. MPI ANY TAG. source status,,,.,, status. Fig. 9 MPI Send MPI Recv MPI SENDRECV(sendbuf,count,datatype,tag, communicator,recvbuf,count,datatype,tag,communicator) void *sendbufin int sendcount (IN) MPI Datatype sendtype (IN) int dest (IN) int sendtag (IN) void *recvbuf(out) int recvcount (IN) MPI Datatype recvtype (IN) int sourcempi ANY SOURCE (IN) int recvtag (IN),MPI SEND MPI RECV,. MPI SENDRECV Fig. 10 MPI Wait() 7
int buf2[100]; error= MPI_Send(buf2,5,MPI_INT,1,1234,MPI_COMM_WORLD); error = MPI_Recv(buf1,5,MPI_INT,0,1234,MPI_COMM_WORLD,&status); int a[50]; error= MPI_Send(a,20,MPI_INT,1,5678,MPI_COMM_WORLD); int n; error= MPI_Send(&n,1,MPI_INT,1,1111,MPI_COMM_WORLD); Fig. 9 MPI 8
Fig. 10. int MPI Isend(void* sendbuf,int sendcount,mpi Datatype sendtype, int dest,mpi Comm comm,mpi Request *request) MPI request ( ) (OUT) MPI Request : int MPI Irecv(void *recvbuf,int recvcount, MPI Datatype recvtype, int source,int recvtag, MPI Comm comm,mpi request *request) int MPI Wait(MPI request *request,mpi Status *status) MPI Wait request request MPI REQUEST NULL status 6.4.2,,,. MPI BCAST(sendbuf,count,datatype,root,communicator) Fig. 11 void *buf int count MPI Datatype datatype int root rank MPI Comm comm int MPI Reduce ( void *sendbuf, void *recvbuf, int count, MPI Datatype datatype, MPI op op, int dest, MPI Comm comm ) 9
Fig. 11. void *sendbuf void *recvbufdest rank MPI Op op MPI GATHER(sendbuf,count,datatype,recvbuf,datatype,communicator) (Fig. 12). Fig. 12 MPI GATHER. MPI SCATTER., (Fig. 13). Fig. 13 MPI SCATTER. 10
MPI ALLGATHER.GATHER.,ALLGATHER (Fig. 14). Fig. 14 MPI ALLGATHER. MPI ALLTOALL,. SCATTER.,ALLTOALL (Fig. 15). Fig. 15 MPI ALLTOALL. URL. http://hamic6.ee.ous.ac.jp/software/mpich-1.1.2/ 6.5 MPI 6.5.1 1 [hello ] #include <stdio.h> #include "mpi.h" int main(int argc, char *argv[]) { int myid,procs,src,dest,tag=1000,count; char inmsg[10],outmsg[]="hello"; MPI_Status stat; MPI_Init(&argc,&argv); 11
MPI_Comm_rank(MPI_COMM_WORLD,&myid); count=sizeof(outmsg)/sizeof(char); if(myid == 0){ src =1; dest =1; /*"hello"*/ MPI_Send(outmsg,count,MPI_CHAR,dest,tag,MPI_COMM_WORLD); MPI_Recv(inmsg,count,MPI_CHAR,src,tag,MPI_COMM_WORLD,&stat); printf("%s from rank %d\n",inmsg,src); }else{ src =0; dest =0; MPI_Recv(inmsg,count,MPI_CHAR,src,tag,MPI_COMM_WORLD,&stat); MPI_Send(outmsg,count,MPI_CHAR,dest,tag,MPI_COMM_WORLD); printf("%s from rank %d\n",inmsg,src); } MPI_Finalize(); return 1; } 6.5.2 2 [] #include <mpi.h> #include <stdio.h> #define M 1000000 int main(int argc,char *argv[]){ int i,j,rank,pnum,data[m],local_sum=0,global_sum,n; MPI_Init(&argc,&argv); MPI_Comm_rank(MPI_COMM_WORLD,&rank); MPI_Comm_size(MPI_COMM_WORLD,&pnum); for(i=0;i<pnum;i++){ if(rank==i){ N=(M+i)/pnum; for(j=0;j<n;j++)data[j]=1; for(j=0;j<n;j++)local_sum+=data[j]; } } MPI_Reduce(&local_sum,&global_sum,1,MPI_INT,MPI_SUM,0,MPI_COMM_WORLD); if(rank==0)printf("sum = %d\n",global_sum); MPI_Finalize(); return(0); 12
} MPI Reduce Fig. 16 13
Fig. 16 1) MPI http://mikilab.doshisha.ac.jp/dia/smpp/cluster2000/ 2) http://mikilab.doshisha.ac.jp/dia/smpp/cluster2000/ 14