mpi Questions
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I'm trying to write a program in C with the MPI library, in which the master process creates a 2D-array and distributes its rows of to the other processes. The matrix has dimensions p*p, in which p...
3
I have the following structure.
typedef struct
{
int *Ai;
double *Ax;
int nz;
}column;
I want to transfer this structure using MPI_Send and MPI_Receive. How do I create an MPI_Datatype for th...
2
I am learning MPI. The first tutorial I followed is here
The code that I run successfully on Windows 7 with MSVC 2010 is :
#include "mpi.h"
#include "iostream.h"
int main(int argc,char *argv []...
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The MPI basic data types correspond to the data types of the host language, except MPI_BYTE and MPI_PACKED. My question is what's the benefit of using those MPI basic data type? Or equivalently, wh...
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I am interested in implementing a sort of event driven dispatch queue using MPI (message passing interface). The basic problem I want to solve is this: I have a master process which inserts jobs in...
Ddene asked 5/10, 2011 at 1:1
1
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With MPI3.0 neighborhood collective communications were introduced.
And in 2 of them (MPI_NEIGHBOR_ALLTOALLW and MPI_INEIGHBOR_ALLTOALLW) displacements (sdispls and rdispls) are arrays of const MPI...
Bartender asked 21/8, 2013 at 13:2
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(Beginner question) I'm trying to spawn processes dynamically using MPI_Comm_Spawn and then broadcast a message to the child processes, but the program stops in the broadcast from the root process ...
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I had some confusion regarding MPI,sockets and TCP/IP.
Are all these three communication protocols which can make use of
different interconnects like Infiniband,ethernet or is it something el...
Bernadinebernadotte asked 14/8, 2013 at 22:28
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I am trying to make an implementation using MPI and Fortran that separates processes wich are on the same node to groups. Does MPI have a routine that can identify that?
I had the idea of separati...
Tommietommy asked 8/8, 2013 at 15:33
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I am attempting to MPI a CUDA code for lattice boltzmann modelling, and have run into frustrating problems with the MPI_Send and MPI_Recv functions. I have verified that I have CUDA-aware MPI with ...
Clouet asked 6/8, 2013 at 1:30
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Whenever I try to call mpi_reduce with mpi_in_place as the send buffer it crashes. A trawl of google reveals this to be have been a problem on Mac OS for OMPI 1.3.3 - but I'm on CentOS with OMPI 1....
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I know,there are some basic function in openMPI implementation for mapping the different processes to different cores of different sockets(if the system have more than one sockets).
--bind-to-soc...
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I know MPI_Send() is a blocking call ,which waits until it is safe to modify the application buffer for reuse. For making the send call synchronous(there should be a handshake with the receiver) , ...
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Given the following scenario, I have N MPI processes each with an object. when the communication stage comes, data "usually small" from these object will be exchanged.
In general, there is data exc...
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I am trying to locally compile software which uses openmpi (1.6.3),
but I got this error:
restraint_camshift2.o:(.toc+0x98): undefined reference to
`ompi_mpi_cxx_op_intercept'
restraint_c...
Footsie asked 9/7, 2013 at 12:42
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Quick Question . for MPI implementation of my code ,i am getting a huge difference in both. I know MPI_Wtime is the real time elapsed by each processor and clock() gives a rough idea of the expecte...
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I have problems when I use a foreach loop (using %dopar%) which invokes a self-defined function. There is not really a problem when I work with Linux, but when I use Windows the self-defined functi...
Cadency asked 27/6, 2013 at 14:0
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Parallel application in python becomes much slower when using mpi rather than multiprocessing module
Lately I've observed a weird effect when I measured performance of my parallel application using the multiprocessing module and mpi4py as communication tools.
The application performs evolutionary...
Spaulding asked 11/6, 2013 at 21:52
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I am running the termstrc yield curve analysis package in R across 10 years of daily bond price data for 5 different countries. This is highly compute intensive, it takes 3200 seconds per country o...
Evangelicalism asked 23/2, 2013 at 9:29
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Regarding MPI_Isend, the MPI standard says "A nonblocking send call indicates that the system may start copying data out of the send buffer. The sender should not access any part of the send buffer...
Lovell asked 12/6, 2013 at 20:37
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I have a shared memory used by multiple processes, these processes are created using MPI.
Now I need a mechanism to control the access of this shared memory.
I know that named semaphore and floc...
Middleaged asked 13/6, 2013 at 7:45
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in a simple MPI program I have used a column wise division of a large matrix.
How can I order the output so that each matrix appears next to the other ordered ?
I have tried this simple code the ef...
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I want to accurately pin my MPI processes to a list of (physical) cores. I refer to the following points of the mpirun --help output:
-cpu-set|--cpu-set <arg0>
Comma-separated list of rang...
Sarthe asked 5/6, 2013 at 21:18
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I have a theoretical question. As you know, for the analysis of scaling, the speedup is defined as S(N) = T(1) / T(N) where T(i) is the runtime with i processors. The efficiency is then defined as ...
Emphysema asked 23/5, 2013 at 15:8
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I am trying to use the doParallel and foreach package but I'm getting reduction in performance using the bootstrapping example in the guide found here CRANpage.
library(doParallel)
library(foreach...
Uniplanar asked 24/5, 2013 at 12:15
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