From 035979a9ee2cc3aa32be2c37d55626bdc853b513 Mon Sep 17 00:00:00 2001
From: Neil Gershenfeld <gersh@cba.mit.edu>
Date: Thu, 11 Jul 2019 23:30:31 -0400
Subject: [PATCH] wip
---
MPI/mpipi3.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/MPI/mpipi3.c b/MPI/mpipi3.c
index 3e505e8..0cf4897 100755
--- a/MPI/mpipi3.c
+++ b/MPI/mpipi3.c
@@ -10,43 +10,42 @@
#include <sys/time.h>
#include <stdint.h>
-#define NPTS 10000000000
+#define NPTS 100000000
#define NLOOP 10
void main(int argc, char** argv) {
uint32_t rank,nproc;
- uint64_t i,j,istart,iend,init_time,start_time,end_time;
- struct timeval init,start,end;
+ uint64_t i,j,istart,iend,start_time,end_time;
+ struct timeval start,end;
double sum,pi,mflops,max;
- gettimeofday(&init,NULL);
MPI_Init(&argc,&argv);
MPI_Comm_rank(MPI_COMM_WORLD,&rank);
MPI_Comm_size(MPI_COMM_WORLD,&nproc);
max = 0;
- for (j = 0; j < NLOOP; ++j) {
- if (rank == 0) {
+ if (rank == 0) {
+ istart = 1+rank*NPTS;
+ iend = (rank+1)*NPTS;
+ for (j = 0; j < NLOOP; ++j) {
MPI_Barrier(MPI_COMM_WORLD);
gettimeofday(&start,NULL);
- istart = 1+rank*NPTS;
- iend = (rank+1)*NPTS;
sum = 0.0;
for (i = istart; i <= iend; ++i)
sum += 0.5/((i-0.75)*(i-0.25));
MPI_Reduce(&sum,&pi,1,MPI_DOUBLE,MPI_SUM,0,MPI_COMM_WORLD);
gettimeofday(&end,NULL);
- init_time = init.tv_sec*1e6+init.tv_usec;
start_time = start.tv_sec*1e6+start.tv_usec;
end_time = end.tv_sec*1e6+end.tv_usec;
mflops = nproc*NPTS*(5.0/(end_time-start_time));
printf("processes = %d, NPTS = %ld, pi = %f\n",nproc,NPTS,pi);
- printf("init = %f, time = %f\n",(start_time-init_time)/1.0e6,(end_time-start_time)/1.0e6);
if (mflops > max) max = mflops;
- printf("estimated MFlops = %f, max MFlops = %f\n",mflops,max);
+ printf("time = %f, estimated MFlops = %f, max = %f\n",(end_time-start_time)/1.0e6,mflops,max);
}
- else {
+ }
+ else {
+ istart = 1+rank*NPTS;
+ iend = (rank+1)*NPTS;
+ for (j = 0; j < NLOOP; ++j) {
MPI_Barrier(MPI_COMM_WORLD);
- istart = 1+rank*NPTS;
- iend = (rank+1)*NPTS;
sum = 0.0;
for (i = istart; i <= iend; ++i)
sum += 0.5/((i-0.75)*(i-0.25));
--
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