At first, try to allocate linspaced on all ranks
linspaced = new double[num];
then use the pointer as the first parameter of MPI_Bcast
MPI_Bcast(linspaced, num, MPI_DOUBLE, 0, MPI_COMM_WORLD);
this mailing list is to discuss MPI stuff specific to Open MPI.
if you have a doubt whether your problem is specific to Open MPI,
you can try to use an other MPI library such as mpich or its derivate
(mvapich, Intel MPI, ...)
if both MPI implementations fail, then the odds are the issue is in your
app,
and forum such as stack overflow are more appropriate to look for help
Cheers,
Gilles
----- Original Message -----
> @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:
> >
> > Send users mailing list submissions to
> > users@lists.open-mpi.org
> >
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> >
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> > than "Re: Contents of users digest..."
> >
> >
> > Today's Topics:
> >
> > 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.
> >
> > _
> > *SAVE WATER ** ~ **SAVE ENERGY**~ **~ **SAVE EARTH *[image:
> > Earth-22-june.gif (7996 bytes)]
> >
> > http://sites.google.com/site/kolukulasivasrinivas/
> >
> > Siva Srinivas Kolukula, PhD
> > *Scientist - B*
> > Indian Tsunami Early Warning Centre (ITEWC)
> > Advisory Services and Satellite Oceanography Group (ASG)
> > Indian National Centre for Ocean Information Services (INCOIS)
> > "Ocean Valley"
> > Pragathi Nagar (B.O)
> > Nizampet (S.O)
> > Hyderabad - 500 090
> > Telangana, INDIA
> >
> > Office: 040 23886124
> >
> >
> > *Cell: +91 9381403232; +91 8977801947*
> >
> > On Wed, May 24, 2017 at 4:42 PM, Pranav Sumanth <pranav.d.sumanth@
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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