[mpich-discuss] where mpi waitsome only returns one request each time
myself
chcdlf at 126.com
Sun Oct 19 21:23:43 CDT 2014
I run several times of the program, the results are as the same as before. Could you tell me your MPICH version and compiling parameters? The version of my MPICH is 3.1.3, I compile it as
$ mpirun --version
HYDRA build details:
Version: 3.1.3
Release Date: Wed Oct 8 09:37:19 CDT 2014
CC: gcc -fPIC
CXX: g++
F77: gfortran
F90: gfortran
Configure options: '--disable-option-checking' '--prefix=/usr/local/mpich3' '--with-device=ch3:nemesis' 'CFLAGS=-fPIC -O2' '--disable-fortran' '--cache-file=/dev/null' '--srcdir=.' 'CC=gcc' 'LDFLAGS= ' 'LIBS=-lpthread ' 'CPPFLAGS= -I/home/valder/Downloads/Software/mpi/mpich-3.1.3/src/mpl/include -I/home/valder/Downloads/Software/mpi/mpich-3.1.3/src/mpl/include -I/home/valder/Downloads/Software/mpi/mpich-3.1.3/src/openpa/src -I/home/valder/Downloads/Software/mpi/mpich-3.1.3/src/openpa/src -D_REENTRANT -I/home/valder/Downloads/Software/mpi/mpich-3.1.3/src/mpi/romio/include'
Process Manager: pmi
Launchers available: ssh rsh fork slurm ll lsf sge manual persist
Topology libraries available: hwloc
Resource management kernels available: user slurm ll lsf sge pbs cobalt
Checkpointing libraries available:
Demux engines available: poll select
the whole program is
=========
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
typedef unsigned char byte;
int main(int argc, char *argv[]){
int rank,size;
byte buf[10][10];
MPI_Request req[10];
MPI_Status stat[10];
int outcount;
int array_of_indices[10];
int i;
int complete = 0;
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
if(rank==0) {
for(i =0; i< 10;i++){
MPI_Isend(buf[i], 10, MPI_BYTE, 1, 123, MPI_COMM_WORLD, &req[i]);
}
printf("post send\n");
}else {
for(i=0; i< 10;i++){
MPI_Irecv(buf[i], 10, MPI_BYTE, 0, 123, MPI_COMM_WORLD, &req[i]);
}
printf("post recv\n");
}
for (;;){
MPI_Waitsome(10, req, &outcount, array_of_indices, stat);
complete += outcount;
printf("rank %d %d index %d\n", rank, outcount, array_of_indices[0]);
if(complete == 10)
break;
}
printf("rank %d complete\n", rank);
MPI_Finalize();
}
=========
I compile it as
$ mpicc -o tests testsome.c
and run as
$ mpirun -n 2 ./tests
At 2014-10-20 09:02:39, "Junchao Zhang" <jczhang at mcs.anl.gov> wrote:
I think it is random. For example, I ran your code and its output was:
post recv
post send
rank 0 10 index 0
rank 0 complete
rank 1 1 index 0
rank 1 9 index 1
rank 1 complete
--Junchao Zhang
On Sun, Oct 19, 2014 at 9:48 AM, myself <chcdlf at 126.com> wrote:
Because I want to understand the behavior of MPI_Waitsome, I change the program as fellow. MPI can waitsome 10 Isend request once time, while waitsome 1 Irecv request each time. Why waitsome-Irecv can not be more than 1 as I expect?
=====
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
if(rank==0) {
for(i =0; i< 10;i++){
MPI_Isend(buf[i], 10, MPI_BYTE, 1, 123, MPI_COMM_WORLD, &req[i]);
}
printf("post send\n");
}else {
for(i=0; i< 10;i++){
MPI_Irecv(buf[i], 10, MPI_BYTE, 0, 123, MPI_COMM_WORLD, &req[i]);
}
printf("post recv\n");
}
for (;;){
MPI_Waitsome(10, req, &outcount, array_of_indices, stat);
complete += outcount;
printf("rank %d %d index %d\n", rank, outcount, array_of_indices[0]);
if(complete == 10)
break;
}
printf("rank %d complete\n", rank);
MPI_Finalize();
=====
$ mpirun -n 2 ./tests
post send
post recv
rank 0 10 index 0
rank 0 complete
rank 1 1 index 0
rank 1 1 index 1
rank 1 1 index 2
rank 1 1 index 3
rank 1 1 index 4
rank 1 1 index 5
rank 1 1 index 6
rank 1 1 index 7
rank 1 1 index 8
rank 1 1 index 9
rank 1 complete
At 2014-10-19 22:36:25, "Bland, Wesley B." <wbland at anl.gov> wrote:
You need to move your waitany outside of the if statement so both ranks execute it.
On Oct 19, 2014, at 9:33 AM, myself <chcdlf at 126.com> wrote:
Here is my test program
======
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
typedef unsigned char byte;
int main(int argc, char *argv[]){
MPI_Init(&argc, &argv);
int rank,size;
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
byte buf[10][10];
MPI_Request req[10];
MPI_Status stat[10];
int outcount;
int array_of_indices[10];
int i;
if(rank==0) {
for(i =0; i< 10;i++){
MPI_Isend(buf[i], 10, MPI_BYTE, 1, 123, MPI_COMM_WORLD, &req[i]);
}
printf("post send\n");
MPI_Waitall(10, req, stat);
printf("send over\n");
}else {
for(i=0; i< 10;i++){
MPI_Irecv(buf[i], 10, MPI_BYTE, 0, 123, MPI_COMM_WORLD, &req[i]);
}
printf("post recv\n");
for (i=0;i<10;i++){
MPI_Waitsome(10, req, &outcount, array_of_indices, stat);
printf("%d index %d\n", outcount, array_of_indices[0]);
}
}
MPI_Finalize();
}
======
get the result like this
======
$ mpirun -n 2 ./tests
post send
send over
post recv
1 index 0
1 index 1
1 index 2
1 index 3
1 index 4
1 index 5
1 index 6
1 index 7
1 index 8
1 index 9
======
I think I should get some completed receive connection, not just 1.
_______________________________________________
discuss mailing list discuss at mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss
_______________________________________________
discuss mailing list discuss at mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mpich.org/pipermail/discuss/attachments/20141020/6319cc48/attachment.html>
-------------- next part --------------
_______________________________________________
discuss mailing list discuss at mpich.org
To manage subscription options or unsubscribe:
https://lists.mpich.org/mailman/listinfo/discuss
More information about the discuss
mailing list