Hi, In my 4 nodes cluster I want to run two MPI_Reduce on two communicators (one using Node1, Node2 and other using Node3, Node4). Now to create communicator I used ... MPI_Comm MPI_COMM_G1, MPI_COMM_G2; MPI_Group g0, g1, g2; MPI_Comm_group(MPI_COMM_WORLD,&g0); MPI_Group_incl(g0,g_size,&r_array[0],&g1); MPI_Group_incl(g0,g_size,&r_array[2],&g2); MPI_Comm_create(MPI_COMM_WORLD,g1,&MPI_COMM_G1); MPI_Comm_create(MPI_COMM_WORLD,g2,&MPI_COMM_G2);
And then I used f(myrank = 0 || myrank == 1) MPI_Reduce(corrbuf,corr_sum,CORR_SIZE,MPI_FLOAT,MPI_SUM,0,MPI_COMM_G1); if(myrank = 2 || myrank == 3) MPI_Reduce(corrbuf,corr_sum,CORR_SIZE,MPI_FLOAT,MPI_SUM,0,MPI_COMM_G2); But the program terminate because of "An error occurred in MPI_Reduce"! Can anybody help me, what is the wrong I am doing?
