In irregular.cpp use simpler and slightly faster MPI_Reduce_scatter_block() (8e75616c) · Commits · 郑智淋 / lammps

src/irregular.cpp

+2 −6

Original line number	Diff line number	Diff line
		@@ -297,11 +297,9 @@ int Irregular::create_atom(int n, int sizes, int proclist, int sortflag)

		// setup for collective comm
		// work1 = 1 for procs I send a message to, not including self
		// work2 = 1 for all procs, used for ReduceScatter

		for (i = 0; i < nprocs; i++) {
		work1[i] = 0;
		work2[i] = 1;
		}
		for (i = 0; i < n; i++) work1[proclist[i]] = 1;
		work1[me] = 0;
		@@ -318,7 +316,7 @@ int Irregular::create_atom(int n, int sizes, int proclist, int sortflag)
		MPI_Allreduce(work1,work2,nprocs,MPI_INT,MPI_SUM,world);
		nrecv_proc = work2[me];
		#else
		MPI_Reduce_scatter(work1,&nrecv_proc,work2,MPI_INT,MPI_SUM,world);
		MPI_Reduce_scatter_block(work1,&nrecv_proc,1,MPI_INT,MPI_SUM,world);
		#endif
		#endif

		@@ -545,11 +543,9 @@ int Irregular::create_data(int n, int *proclist, int sortflag)

		// setup for collective comm
		// work1 = 1 for procs I send a message to, not including self
		// work2 = 1 for all procs, used for ReduceScatter

		for (i = 0; i < nprocs; i++) {
		work1[i] = 0;
		work2[i] = 1;
		}
		for (i = 0; i < n; i++) work1[proclist[i]] = 1;
		work1[me] = 0;
		@@ -566,7 +562,7 @@ int Irregular::create_data(int n, int *proclist, int sortflag)
		MPI_Allreduce(work1,work2,nprocs,MPI_INT,MPI_SUM,world);
		nrecv_proc = work2[me];
		#else
		MPI_Reduce_scatter(work1,&nrecv_proc,work2,MPI_INT,MPI_SUM,world);
		MPI_Reduce_scatter_block(work1,&nrecv_proc,1,MPI_INT,MPI_SUM,world);
		#endif
		#endif