mpi/omp_comm round-off error spotting (2487fe8b) · Commits · HPC_SCHOOL / HPC_SCHOOL_2024

jacobi/mpi/comp_comm/make_mpi_path

+1 −1

Original line number	Diff line number	Diff line
		# set the MPI install path

		MPI_INSTALL_PATH = /home/gozzilla/software/openmpi/openmpi-5.0.3
		MPI_INSTALL_PATH = /home/darkenergy/software/openmpi/openmpi-5.0.3

jacobi/mpi/comp_comm/src/jacobi_2D_mpi_comp_comm.c

+79 −61

Original line number	Diff line number	Diff line
		@@ -218,21 +218,7 @@ int main(int argc, char **argv)
		-------------------------------------------------------- */

		const int ibeg = NGHOST;
		/* const int iend = ibeg + NX_GLOB - 1; */
		/* const int nx = iend - ibeg + 1; */
		/* const int nx_tot = nx + 2 * NGHOST; */

		const int jbeg = NGHOST;
		/* const int jend = jbeg + NY_GLOB - 1; */
		/* const int ny = jend - jbeg + 1; */
		/* const int ny_tot = ny + 2 * NGHOST; */

		/* if (rank == MASTER) */
		/* { */
		/* printf("\n\t Grid indices:"); */
		/* printf("\n\t\t ibeg, iend = %d, %d; nx_tot = %d" ,ibeg, iend, nx_tot); */
		/* printf("\n\t\t jbeg, jend = %d, %d; ny_tot = %d\n\n",jbeg, jend, ny_tot); */
		/* } */

		/* --------------------------------------------------------
		2. Generate grids, allocate memory
		@@ -426,7 +412,28 @@ void JacobiAlgorithm(MyData **const restrict Phi,
		Phi[j][i] = 0.25 * (Phi0[j][i-1] + Phi0[j][i+1] +
		Phi0[j-1][i] + Phi0[j+1][i]);

		error += delta[X] delta[Y] * fabs(Phi[j][i] - Phi0[j][i]);
		error += (delta[X] delta[Y] * fabs(Phi[j][i] - Phi0[j][i]));
		} /* loop over columns */
		} /* loop over rows */

		return;
		}

		void get_error(MyData **const restrict Phi,
		MyData **const restrict Phi0,
		const MyData *restrict delta,
		const int jbeg,
		const int jend,
		const int ibeg,
		const int iend,
		MyData *const restrict error)
		{
		*error = 0.0;
		for (int j=jbeg ; j<=jend ; j++)
		{
		for (int i=ibeg ; i<=iend ; i++)
		{
		error += (delta[X] delta[Y] * fabs(Phi[j][i] - Phi0[j][i]));
		} /* loop over columns */
		} /* loop over rows */

		@@ -448,21 +455,25 @@ void Jacobi_Communication(MyData **const restrict Phi,
		const int data_row_size = ThisTask->domain.dim[Y];

		/* First task: issue the communication */
		MPI_Request request[8];
		MPI_Request request[4];

		MyData **const restrict buffer = Phi0;

		/* 4 nonblocking MPI_Irecv */
		MPI_Irecv(&buffer[ThisTask->domain.local_start[X] - 1][ThisTask->domain.local_start[Y] ], data_row_size, MPI_MyDatatype, ThisTask->nbrbottom, 0, ThisTask->comm2d, &request[0]);
		MPI_Irecv(&buffer[ThisTask->domain.local_end[X] + 1][ThisTask->domain.local_start[Y] ], data_row_size, MPI_MyDatatype, ThisTask->nbrtop, 1, ThisTask->comm2d, &request[1]);
		MPI_Irecv(&buffer[ThisTask->domain.local_start[X] ][ThisTask->domain.local_start[Y] - 1], 1, column, ThisTask->nbrleft, 2, ThisTask->comm2d, &request[2]);
		MPI_Irecv(&buffer[ThisTask->domain.local_start[X] ][ThisTask->domain.local_end[Y] + 1], 1, column, ThisTask->nbrright, 3, ThisTask->comm2d, &request[3]);
		MPI_Isendrecv(&buffer[ThisTask->domain.local_end[X] ][ThisTask->domain.local_start[Y] ], data_row_size, MPI_MyDatatype, ThisTask->nbrtop, 0,
		&buffer[ThisTask->domain.local_start[X] - 1][ThisTask->domain.local_start[Y] ], data_row_size, MPI_MyDatatype, ThisTask->nbrbottom, 0,
		ThisTask->comm2d, &request[0]);

		MPI_Isendrecv(&buffer[ThisTask->domain.local_start[X] ][ThisTask->domain.local_start[Y] ], data_row_size, MPI_MyDatatype, ThisTask->nbrbottom, 1,
		&buffer[ThisTask->domain.local_end[X] + 1][ThisTask->domain.local_start[Y] ], data_row_size, MPI_MyDatatype, ThisTask->nbrtop, 1,
		ThisTask->comm2d, &request[1]);

		/* 4 nonblocking MPI_Isend */
		MPI_Isend(&buffer[ThisTask->domain.local_end[X] ][ThisTask->domain.local_start[Y]], data_row_size, MPI_MyDatatype, ThisTask->nbrtop, 0, ThisTask->comm2d, &request[4]);
		MPI_Isend(&buffer[ThisTask->domain.local_start[X]][ThisTask->domain.local_start[Y]], data_row_size, MPI_MyDatatype, ThisTask->nbrbottom, 1, ThisTask->comm2d, &request[5]);
		MPI_Isend(&buffer[ThisTask->domain.local_start[X]][ThisTask->domain.local_end[Y] ], 1, column, ThisTask->nbrright, 2, ThisTask->comm2d, &request[6]);
		MPI_Isend(&buffer[ThisTask->domain.local_start[X]][ThisTask->domain.local_start[Y]], 1, column, ThisTask->nbrleft, 3, ThisTask->comm2d, &request[7]);
		MPI_Isendrecv(&buffer[ThisTask->domain.local_start[X] ][ThisTask->domain.local_end[Y] ], 1, column, ThisTask->nbrright, 2,
		&buffer[ThisTask->domain.local_start[X] ][ThisTask->domain.local_start[Y] - 1], 1, column, ThisTask->nbrleft, 2,
		ThisTask->comm2d, &request[2]);

		MPI_Isendrecv(&buffer[ThisTask->domain.local_start[X] ][ThisTask->domain.local_start[Y] ], 1, column, ThisTask->nbrleft, 3,
		&buffer[ThisTask->domain.local_start[X] ][ThisTask->domain.local_end[Y] + 1], 1, column, ThisTask->nbrright, 3,
		ThisTask->comm2d, &request[3]);

		/************************************** computation **************************************/
		/* perform the computation with the local data, (i.e. ghost cells are not required) */
		@@ -473,39 +484,46 @@ void Jacobi_Communication(MyData **const restrict Phi,
		const int ibeg = ThisTask->domain.local_start[Y] + 1;
		const int iend = ThisTask->domain.local_end[Y] - 1;

		/* wait the data on the boundaries */
		MPI_Waitall(8, request, MPI_STATUSES_IGNORE);
		*error = 0.0;
		JacobiAlgorithm(Phi, Phi0, delta, jbeg, jend, ibeg, iend, error);

		/*********************************************************************************************/

		/* wait the data on the boundaries */
		MPI_Waitall(4, request, MPI_STATUSES_IGNORE);

		/* nbrbottom */
		JacobiAlgorithm(Phi, Phi0, delta,
		ThisTask->domain.local_start[X], ThisTask->domain.local_start[X],
		ThisTask->domain.local_start[Y], ThisTask->domain.local_end[Y],
		error);

		/* nbrtop */
		JacobiAlgorithm(Phi, Phi0, delta,
		ThisTask->domain.local_end[X], ThisTask->domain.local_end[X],
		ThisTask->domain.local_start[Y], ThisTask->domain.local_end[Y],
		error);

		/* nbrleft */
		JacobiAlgorithm(Phi, Phi0, delta,
		ThisTask->domain.local_start[X], ThisTask->domain.local_end[X],
		ThisTask->domain.local_start[Y], ThisTask->domain.local_start[Y],
		error);

		/* nbrright */
		JacobiAlgorithm(Phi, Phi0, delta,
		ThisTask->domain.local_start[X], ThisTask->domain.local_end[X],
		ThisTask->domain.local_end[Y], ThisTask->domain.local_end[Y],
		error);

		/* Round-off error fixing ??? */
		{
		*error = 0.0;
		/* JacobiAlgorithm(Phi, Phi0, delta, jbeg, jend, ibeg, iend, error); */
		JacobiAlgorithm(Phi, Phi0, delta, jbeg-1, jend+1, ibeg-1, iend+1, error);

		/* /\* wait the data on the boundaries \/ /
		/* MPI_Waitall(8, request, MPI_STATUSES_IGNORE); */

		/* /\* nbrbottom \/ /
		/* JacobiAlgorithm(Phi, Phi0, delta, */
		/* ThisTask->domain.local_start[X], ThisTask->domain.local_start[X], */
		/* ThisTask->domain.local_start[Y], ThisTask->domain.local_end[Y], */
		/* error); */

		/* /\* nbrtop \/ /
		/* JacobiAlgorithm(Phi, Phi0, delta, */
		/* ThisTask->domain.local_end[X], ThisTask->domain.local_end[X], */
		/* ThisTask->domain.local_start[Y], ThisTask->domain.local_end[Y], */
		/* error); */

		/* /\* nbrleft \/ /
		/* JacobiAlgorithm(Phi, Phi0, delta, */
		/* ThisTask->domain.local_start[X], ThisTask->domain.local_end[X], */
		/* ThisTask->domain.local_start[Y], ThisTask->domain.local_start[Y], */
		/* error); */

		/* /\* nbrright \/ /
		/* JacobiAlgorithm(Phi, Phi0, delta, */
		/* ThisTask->domain.local_start[X], ThisTask->domain.local_end[X], */
		/* ThisTask->domain.local_end[Y], ThisTask->domain.local_end[Y], */
		/* error); */
		get_error(Phi, Phi0, delta,
		ThisTask->domain.local_start[X], ThisTask->domain.local_end[X],
		ThisTask->domain.local_start[Y], ThisTask->domain.local_end[Y],
		error);
		}

		MPI_Type_free(&column);

jacobi/mpi/comp_comm/include/allvars.h

+1 −1

File changed.

Contains only whitespace changes.