@Siva, Thanks for your inputs. I changed it and the process no longer hangs.
I now modified my main file to:
#include <iostream>
#include <utils.h>
#include <mpi.h>
using namespace std;
int main(int argc, const char * argv[]) {
float start = 0., end = 1.;
unsigned long int num = 100;
double *linspaced;
float delta = (end - start) / num;
int size, rank;
MPI_Init(NULL, NULL);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Status status;
// These have to be converted into unsigned long ints
int casesPerNode = num / size;
int remainderCases = num % size;
if(rank==0){
linspaced = new double[num];
if(remainderCases!=0){
linspace(&linspaced[(size-1)*casesPerNode], end -
delta*remainderCases, end, remainderCases);
} else {
linspace(&linspaced[(size-1)*casesPerNode], end -
delta*casesPerNode, end, casesPerNode);
}
}
MPI_Bcast(&linspaced, num, MPI_DOUBLE, 0, MPI_COMM_WORLD);
if(rank != 0) {
// Sending job to master node.
// The node is already overloaded with coordinating.
// Additional task now is also to take on remainder cases.
// cout << "Rank " << rank << endl;
float start_in = start + casesPerNode*delta*(rank-1);
float end_in = start + casesPerNode*delta*(rank) - delta;
linspace(&linspaced[(rank-1)*casesPerNode], start_in, end_in,
casesPerNode);
}
MPI_Finalize();
for(int i=0; i< num; i++){
cout << *(linspaced + i) << endl;
}
return 0;
}
On execution the error generated is:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
[wlan-145-94-163-183:09801] *** Process received signal ***
[wlan-145-94-163-183:09801] Signal: Segmentation fault: 11 (11)
[wlan-145-94-163-183:09801] Signal code: Address not mapped (1)
[wlan-145-94-163-183:09801] Failing at address: 0x7fed2d314220
[wlan-145-94-163-183:09802] *** Process received signal ***
[wlan-145-94-163-183:09802] Signal: Segmentation fault: 11 (11)
[wlan-145-94-163-183:09802] Signal code: Address not mapped (1)
[wlan-145-94-163-183:09802] Failing at address: 0x7fed2d3142e8
Received start :0.5 End :0.74 Num_in :25
[wlan-145-94-163-183:09803] *** Process received signal ***
[wlan-145-94-163-183:09803] Signal: Segmentation fault: 11 (11)
[wlan-145-94-163-183:09803] Signal code: Address not mapped (1)
[wlan-145-94-163-183:09803] Failing at address: 0x7fed2d3143b0
[wlan-145-94-163-183:09801] [ 0] 0 libsystem_platform.dylib
0x00007fffd6902b3a _sigtramp + 26
[wlan-145-94-163-183:09801] [ 1] 0 ???
0x0000000000000000 0x0 + 0
[wlan-145-94-163-183:09801] [ 2] 0 test
0x0000000108afafda main + 602
[wlan-145-94-163-183:09801] [ 3] 0 libdyld.dylib
0x00007fffd66f3235 start + 1
[wlan-145-94-163-183:09801] *** End of error message ***
[wlan-145-94-163-183:09802] [ 0] 0 libsystem_platform.dylib
0x00007fffd6902b3a _sigtramp + 26
[wlan-145-94-163-183:09802] [ 1] 0 ???
0x0000000000000000 0x0 + 0
[wlan-145-94-163-183:09802] [ 2] 0 test
0x0000000107ed5fda main + 602
[wlan-145-94-163-183:09802] [ 3] 0 libdyld.dylib
0x00007fffd66f3235 start + 1
[wlan-145-94-163-183:09802] *** End of error message ***
[wlan-145-94-163-183:09803] [ 0] 0 libsystem_platform.dylib
0x00007fffd6902b3a _sigtramp + 26
[wlan-145-94-163-183:09803] [ 1] 0 ???
0x0000000000000000 0x0 + 0
[wlan-145-94-163-183:09803] [ 2] 0 test
0x000000010f314fda main + 602
[wlan-145-94-163-183:09803] [ 3] 0 libdyld.dylib
0x00007fffd66f3235 start + 1
[wlan-145-94-163-183:09803] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 3 with PID 0 on node wlan-145-94-163-183
exited on signal 11 (Segmentation fault: 11).
—————————————————————————————————————
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
What could be going wrong here?
Best Regards,
Pranav
> On 24 May 2017, at 13:47, users-requ...@lists.open-mpi.org wrote:
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> 1. Re: All processes waiting on MPI_Bcast (Siva Srinivas Kolukula)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 24 May 2017 17:16:59 +0530
> From: Siva Srinivas Kolukula <allwayzit...@gmail.com>
> To: Open MPI Users <users@lists.open-mpi.org>
> Subject: Re: [OMPI users] All processes waiting on MPI_Bcast
> Message-ID:
> <cal9xuuaducvu1qten5345q4zrezuop7lw7aox605jpwe3na...@mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> When you call mpi_bcast all the processors should be called....in you code
> you are calling mpi_bcast in all the roots expect root. Try keeping
> mpi_bcast out of if condition.
>
> _
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>
> http://sites.google.com/site/kolukulasivasrinivas/
>
> Siva Srinivas Kolukula, PhD
> *Scientist - B*
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>
> On Wed, May 24, 2017 at 4:42 PM, Pranav Sumanth <pranav.d.suma...@gmail.com>
> wrote:
>
>> Greetings!
>>
>> I include a static header file utils.h with a function linspace. My
>> main.cpp file is as follows:
>>
>> #include <iostream>#include <utils.h>#include <mpi.h>
>> using namespace std;
>> int main(int argc, const char * argv[]) {
>>
>> float start = 0., end = 1.;
>> unsigned long int num = 100;
>>
>> double *linspaced;
>>
>> float delta = (end - start) / num;
>> int size, rank;
>>
>>
>> MPI_Init(NULL, NULL);
>>
>> MPI_Comm_size(MPI_COMM_WORLD, &size);
>> MPI_Comm_rank(MPI_COMM_WORLD, &rank);
>> MPI_Status status;
>>
>> // These have to be converted into unsigned long ints
>> int casesPerNode = num / size;
>> int remainderCases = num % size;
>>
>>
>> if(rank==0){
>> linspaced = new double[num];
>>
>> if(remainderCases!=0){
>> linspace(&linspaced[(size-1)*casesPerNode], end -
>> delta*remainderCases, end, remainderCases);
>>
>> } else {
>> linspace(&linspaced[(size-1)*casesPerNode], end -
>> delta*casesPerNode, end, casesPerNode);
>>
>> }
>>
>> } else {
>>
>> MPI_Bcast(&linspaced, num, MPI_DOUBLE, 0, MPI_COMM_WORLD);
>>
>>
>> // Sending job to master node.
>> // The node is already overloaded with coordinating.
>> // Additional task now is also to take on remainder cases.
>>
>>
>> // cout << "Rank " << rank << endl;
>> float start_in = start + casesPerNode*delta*(rank-1);
>> float end_in = start + casesPerNode*delta*(rank) - delta;
>>
>> linspace(&linspaced[(rank-1)*casesPerNode], start_in, end_in,
>> casesPerNode);
>>
>>
>> }
>>
>> MPI_Barrier(MPI_COMM_WORLD);
>> // cout << "Print Here Rank " << rank << endl ;
>>
>>
>> MPI_Finalize();
>>
>> /*
>> for(int i=0; i< num; i++){
>> cout << *(linspaced + i) << endl;
>> }
>> */
>>
>> return 0;
>> }
>>
>> and my utils.h file is:
>>
>> void linspace(double *ret, double start_in, double end_in, unsigned long int
>> num_in){
>> /* This function generates equally spaced elements and returns
>> an array with the results */
>>
>>
>> assert(num_in!=0);
>>
>>
>> cout << "\tReceived start :" << start_in << "\tEnd :" << end_in <<
>> "\tNum_in :" << num_in << endl;
>>
>> double delta_in = (end_in - start_in) / (num_in - 1);
>>
>> if(num_in == 1){
>> *(ret) = start_in;
>> }
>>
>> *(ret) = start_in;
>> for(int i=1; i < num_in-1; i++) {
>> *(ret + i) = *(ret + i - 1) + delta_in;
>> }
>> *(ret + (num_in - 1)) = end_in;
>>
>> /*
>> cout << "Finished executing linspace " << endl;
>> for(int i = 0; i<num_in; i++){
>> cout << "Address : " << &ret << "\tElement " << i << " : " << *(ret + i)
>> << endl;
>> }
>> */}
>>
>> I am unable to diagnose why my code gets stuck at MPI_Bcast. What could I
>> do to fix it?
>>
>> Thanks
>>
>> PS: I?m new to OpenMPI and may have a lot of these doubts initially.
>> Thanks for patience and support.
>>
>> _______________________________________________
>> users mailing list
>> users@lists.open-mpi.org
>> https://rfd.newmexicoconsortium.org/mailman/listinfo/users
>>
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