From ab66905e1c127fd0db4c46ff9ebaa2907fabff76 Mon Sep 17 00:00:00 2001
From: David Goz <david.goz@inaf.it>
Date: Sat, 22 Jun 2024 11:27:49 +0200
Subject: [PATCH] /mpi/comp_comm/ comments global data structure
---
.../comp_comm/src/jacobi_2D_mpi_comp_comm.c | 32 +++++++++----------
1 file changed, 15 insertions(+), 17 deletions(-)
diff --git a/jacobi/mpi/comp_comm/src/jacobi_2D_mpi_comp_comm.c b/jacobi/mpi/comp_comm/src/jacobi_2D_mpi_comp_comm.c
index 1b620e9..d4de3f4 100644
--- a/jacobi/mpi/comp_comm/src/jacobi_2D_mpi_comp_comm.c
+++ b/jacobi/mpi/comp_comm/src/jacobi_2D_mpi_comp_comm.c
@@ -19,25 +19,25 @@ MyData **global_phi;
typedef struct MyGrid
{
- int local_start[NDIM];
- int local_end[NDIM];
- int global_start[NDIM];
- int global_end[NDIM];
- int dim[NDIM];
+ int local_start[NDIM]; /* Local start index in each dimension */
+ int local_end[NDIM]; /* Local end index in each dimension */
+ int global_start[NDIM]; /* Global start index in each dimension */
+ int global_end[NDIM]; /* Global end index in each dimension */
+ int dim[NDIM]; /* Local domain size (no ghosts) */
} myDomain;
typedef struct Task_2D_Cartesian
{
- int rank;
- int nranks;
- int coords[NDIM];
- myDomain domain;
- int nbrtop;
- int nbrbottom;
- int nbrleft;
- int nbrright;
- MPI_Comm comm2d;
+ int rank; /* Local process rank */
+ int nranks; /* Communicator size */
+ int coords[NDIM]; /* Cartesian topology coordinate */
+ myDomain domain; /* MyGrid structure (defined above) */
+ int nbrtop; /* Top neighbor process in cartesian topology */
+ int nbrbottom; /* Bottom neighbor process in cartesian topology */
+ int nbrleft; /* Left neighbor process in cartesian topology */
+ int nbrright; /* Right neighbor process in cartesian topology */
+ MPI_Comm comm2d; /* Cartesian communicator */
} Task;
/* function prototypes */
@@ -136,9 +136,7 @@ int main(int argc, char **argv)
/************************************************************************************************************/
/* 2D MPI-cartesian decomposition:
- the grids are replicated across the MPI processes.
- This approach is not the most efficient in terms of memory usage,
- because the arrays are replicated across MPI process instead of to be distributed */
+ the grids are distributed across the MPI processes.
/* get the reminder, i.e. take into account uneven
decomposition of points among the processes */
--
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