Using MPI_Type_Vector and MPI_Gather, in C

I am trying to multiply square matrices in parallele with MPI. I use a MPI_Type_vector to send square submatrixes (arrays of float) to the processes, so they can calculate subproducts. Then, for...

MPI_Type_create_subarray and MPI_Gather

I have to solve a little mpi problem. I have 4 slaves processes and each of these wants to send a 2d subarray (CHUNK_ROWS X CHUNK_COLUMNS) to master 0. Master 0 collects all chunks in...

Python context manager: conditionally executing body?

I'm writing an MPI-based application (but MPI doesn't matter in my question, I mention it only to expose the rationale) and in some cases, when there is less work items than processes, I need to...

Migrating from PVM to MPI

I'm working on migrating a project from PVM to MPI. I wanted to ask if anyone here has done so before and if there exists any tutorials or manuals on the correspondance between functions in PVM and MPI.

I am not able to compile with MPI compiler with C++

I was trying to compile a very simple MPI hello_world: #include <stdio.h> #include <mpi.h> int main(int argc, char *argv[]) { int numprocs, rank, namelen; char...

Problems running MPI (OpenMPI) app on Linux on ARM

I am trying to follow this tutorial for building and running an MPI application on an ARM based Ubuntu 11.10 system. When installing open-mpi environment on my PC machine, the sample program runs...

Error creating bean with name 'entityManagerFactory'

I have a web application that uses spring, hibernate and JPA. When I want to run my DAO unit tests, I get the following error: Caused by:...

CUDA driver API equivalent for cudaSetDevice

What is the CUDA driver's API equivalent for the runtime API function cudaSetDevice? I was looking into the driver API and cannot find an equivalent function. What I can do...

Configure error with Mac OS X 10.8.5 Xcode 5.0.2: clang: error: argument to '-V' is missing (expected 1 value) clang: error: no input files

on MacOSX 10.8.5, after upgrading to Xcode 5.0.2 (and upgrading/installing the Command Line Tools (from within Xcode preferences) I was installing FFTW 3.3.3 and Open MPI 1.6.5 by configuring them...

How to identify conda package dependents?

For a given conda package, how to I list the packages that depend on it? I recently installed anaconda on a university cluster that already had a version of MPI (openmpi). The mpich2 package and...

mpirun was unable to find the specified executable file

I have problems compiling this code using OpenMPI.Since I am a bit new to the concepts of using OpenMPI, it would be great if someone of you could give me a hint to the mistake here. Compiling...

Error when installing mpi4py

I'm trying to install mpi4py using pip install mpi4py, but I'm getting the following error: error: Cannot find 'mpi.h' header. Check your configuration!!! Earlier in the same error report I...

Use gdb to debug MPI in multiple screen windows

If I have an MPI program that I want to debug with gdb while being able to see all of the separate processes' outputs, I can use: mpirun -n <NP> xterm -hold -e gdb -ex run --args ./program [arg1]...

MPI_Scatter structs in C

Is there a clean way to use MPI_Scatter to scatter structs that doesn't involve pack or unpack? Let's say I have a struct like this: struct Foo { int a; int* b; int* c; } Where a and b...

Using GDB to debug an MPI program in Fortran

I read this and arrived here, so now I think I should (if not so, please, tell me) rewrite the code { int i = 0; char hostname[256]; gethostname(hostname, sizeof(hostname)); ...

SLURM: Embarrassingly parallel program inside an embarrassingly parallel program

I have a complex model written in Matlab. The model was not written by us and is best thought of as a "black box" i.e. in order to fix the relevant problems from the inside would require...

Why does node.js install two 'node_modules' folders?

Whenever I try to run npm install or npm start I get this error: bash: line 0: cd: packages/react-scripts: No such file or directory npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR!...

"npm run build -- --prod" error on Visual Studio 2017 .NET Core 2.1 Angular

I need an help, i've made a project on Angular based with .Net Core 2.1. So when i try to publish VS return me this error: So the error is: So, i've followed this solution:...

how to debug: if mpi can't run across machine

I have around 20 servers, I use mpi to distribute my task across servers, all the server have the same version of OS (ubuntu 17.10), and all the package is installed with same scripts (of course,...

NG Build fails in Azure Pipelines with NPM error 134

Approx 50% of my hosted builds are failing with npm error 134. I am building the same commit with the same build definition using hosted vs2017. I am building an Angular Application using the...

How to deal with "[Errno 122] Disk quota exceeded" problem when creating new environment by anaconda?

I am trying to create a new environment for Python through Anaconda. But the error keeps coming out saying : Solving environment: failed # >>>>>>>>>>>>>>>>>>>>>> ERROR REPORT...

PyTorch "NCCL error: unhandled system error" during backprop

I am trying to do distributed training with PyTorch and encountered a problem. This runtime error occurs during backprop (first batch, first epoch). File...

Parallel Merge Sort using MPI

I implemented Parallel Merge sort in this code using the tree Structural scheme; but it doesn't sort the Array! Could you take look at it and tell me what is wrong? For communication among the...

Writing a chunk of MPI distributed data via hdf5 in fortran

I have a 3d array distributed into different MPI processes: real :: DATA(i1:i2, j1:j2, k1:k2) where i1, i2, ... are different for each MPI process, but the MPI grid is cartesian. For simplicity...

trying to set up multi-locale chapel on a Raspberry Pi cluster

I a wondering if anyone could provide me with guidance on how to set up multi-locale on a cluster of Raspberry Pi -- a procedure or walk through or even just hints would be welcome. Chapel...

How to execute multiple command in command line with Python 3.x

Thanks, everyone. I am writing a script to execute multiple command in command line. It is one part of my whole script. I have checked many answers, but none of them solved my problem. Some of...

Use CppADCodeGen with CMake FetchContent or ExternalProject

I am not good with CMake, and I cannot find good explanations about how to use its FetchContent functionality. Indeed, most repositories seem to require different treatment, and the rules of such...

Submitting multiple runs to the same node on AzureML

I want to perform hyperparameter search using AzureML. My models are small (around 1GB) thus I would like to run multiple models on the same GPU/node to save costs but I do not know how to achieve...

pybind11: send MPI communicator from Python to CPP

I have a C++ class which I intend to call from python's mpi4py interface such that each node spawns the class. On the C++ side, I'm using the Open MPI library (installed via homebrew) and...