openmpi

问题 I need to pass fragments of vector to all processes to make multiplication operation on matrix . I want to pass a vector (of orginal_size/processes) of vectors. std::vector<double> Algorytm::mnozenie(std::vector< std::vector <double> > matrix,std::vector<double> wektor){ std::vector<double> wynik(matrix.size(),0); if (rozmiar_macierzy_==(int)wektor.size()){ int size=matrix.size(); int world_size; MPI_Comm_size(MPI_COMM_WORLD, &world_size); MPI_Bcast(&size,1 , MPI_INT,0,MPI_COMM_WORLD); MPI

问题 I have a fairly big data set, about 141M lines with .csv formatted. I want to use MPI commands with C++ to copy and manipulate a few columns, but I'm a newbie on both C++ and MPI. So far my code looks like this #include <stdio.h> #include "mpi.h" using namespace std; int main(int argc, char **argv) { int i, rank, nprocs, size, offset, nints, bufsize, N=4; MPI_File fp, fpwrite; // File pointer MPI_Status status; MPI_Offset filesize; MPI_Init(&argc, &argv); MPI_Comm_rank(MPI_COMM_WORLD, &rank);

问题 I was trying to compile mpi_prime.c with openmpi on windows. I tried it with the 32bit and 64bit version of OpenMPI_v1.6.2. I got these outputs. Microsoft (R) C/C++-Optimierungscompiler Version 17.00.61030 für x86 Copyright (C) Microsoft Corporation. Alle Rechte vorbehalten. mpi_prime.c Microsoft (R) Incremental Linker Version 11.00.61030.0 Copyright (C) Microsoft Corporation. All rights reserved. /out:mpi_prime.exe /LIBPATH:C:\Entwicklung\OpenMPI_v1.6.2-x64/lib libmpi_cxx.lib libmpi.lib

问题 I am using Intel MPI and have encountered some confusing behavior when using mpirun in conjunction with slurm. If I run (in a login node) mpirun -n 2 python -c "from mpi4py import MPI; print(MPI.COMM_WORLD.Get_rank())" then I get as output the expected 0 and 1 printed out. If however I salloc --time=30 --nodes=1 and run the same mpirun from the interactive compute node, I get two 0s printed out instead of the expected 0 and 1. Then, if I change -n 2 to -n 3 (still in compute node), I get a

问题 This question might sound a bit weird... Imagine I have an MPI application, but I don't have a system with MPI installed. So I want to compile the application with no MPI support (1-process, 1-thread) without modifying source code. Is that possible? I found somewhere a "mimic_mpi.h" wrapper which is supposed to do exactly what I want. But there were some MPI functions missing in there (e.g., MPI_Cart_create, MPI_Cart_get, etc.), so I didn't succeed. mimic_mpi.h http://openmx.sourcearchive.com

问题 Some module in my python program is calling fork(), and my mpi environment is unhappy with this: A process has executed an operation involving a call to the "fork()" system call to create a child process. Open MPI is currently operating in a condition that could result in memory corruption or other system errors; your job may hang, crash, or produce silent data corruption. The use of fork() (or system() or other calls that create child processes) is strongly discouraged. The process that

问题 I am using OpenMPI 1.3 on a small cluster. This is the function that I am calling: void invertColor_Parallel(struct image *im, int size, int rank) { int i,j,aux,r; int total_pixels = (*im).ih.width * (*im).ih.height; int qty = total_pixels/(size-1); int rest = total_pixels % (size-1); MPI_Status status; //printf("\n%d\n", rank); if(rank == 0) { for(i=1; i<size; i++){ j = i*qty - qty; aux = j; if(rest != 0 && i==size-1) {qty=qty+rest;} //para distrubuir toda la carga //printf("\nj: %d qty: %d

问题 I am using OpenMPI 1.3 on a small cluster. This is the function that I am calling: void invertColor_Parallel(struct image *im, int size, int rank) { int i,j,aux,r; int total_pixels = (*im).ih.width * (*im).ih.height; int qty = total_pixels/(size-1); int rest = total_pixels % (size-1); MPI_Status status; //printf("\n%d\n", rank); if(rank == 0) { for(i=1; i<size; i++){ j = i*qty - qty; aux = j; if(rest != 0 && i==size-1) {qty=qty+rest;} //para distrubuir toda la carga //printf("\nj: %d qty: %d

问题 This code: #include <mpi.h> int main(int argc, char* argv[]) { MPI_Init(&argc, &argv); for (unsigned int iter = 0 ; iter < 1000 ; iter++) MPI_Barrier(MPI_COMM_WORLD); MPI_Finalize(); return 0; } is very long to run with MPICH 3.1.4 . Here are the wall clock (in seconds) for different MPI implementations. On a laptop with 4 processors of 2 cpu cores: | MPI size | MPICH 1.4.1p1 | openmpi 1.8.4 | MPICH 3.1.4 | |----------|---------------|---------------|-------------| | 2 | 0.01 | 0.39 | 0.01 |

问题 I want to generate an string with each process and then gather everything. But the strings created in each process are created by appending ints and chars. I'm still not able to gather everything correctly. I can print all the partial strings one by one, but If I try to print the rcv_string, I only get one partial string or maybe a Segmentation Fault. I've tried putting zeros at the end of strings with memset, reserving memory for the strings dynamically and statically, ... But I don't find