openmp

How to check the version of OpenMP on Linux

Hi, I wonder how to check the version of OpenMP on a Linux remote machine? I don't know where it is installed either. Thanks and regards! ...

Visual C++ 2008: omp.h not found? /openMP is set

I've enabled openMP using the project settings, but when I do #include I get an error the file doesn't exist. I'm using Visual Studio stadnard edition, not Express... what else is missing? Every page I find simply says to turn it on in project settings and it will work. ...

Worker threads stop their work after a moment

I have a serial application that I parallelized using OpenMP. I simply added the following to my main loop : #pragma omp parallel for default(shared) for (int i = 0; i < numberOfEmitters; ++i) { computeTrajectoryParams* params = new computeTrajectoryParams; // defining params... outputs[i] = (int*) ComputeTrajectory(params...

OpenMP on Intel i7

I have a problem with openMP in i7 CPU. I have used openMP just to parallel a 'for' loop. Algorithm was used on several different PC's and worked without any problem. Recently, we tried to run it on i7 system and we got a problem on it. Software usually runs for some time and after several cycles it reported "not enough memory" and we t...

Did Visual Studio 2008 SP1 introduce runtime bugs or am I crazy?

I've been wracking my brains out trying to figure out what the heck is going on with the most recent (non beta) Visual Studio 2008 SP1: My app built with OpenMP runs incredibly slow in the debugger, bringing CPU usage to 100%. When they are run outside the debugger, it merely runs slowly (for a release build). My app built with the Int...

Turn off OpenMP

Hi, In my C++ program, I'd like to run its executable sometimes with and sometimes without using OpenMP (i.e. multi-threading or single-threading). I am considering any of the following two cases how my code is using OpenMP: (1) Assume that my code is only having #include <omp.h> and OpenMP directives. (2) Same as (1) and my code furt...

Why should I use Grand Central Dispatch over OpenMP?

Apple introduced Grand Central Dispatch (a thread pool) in Snow Leopard, but haven't gone into why one should use it over OpenMP, which is cross-platform and also works on Leopard. They're both pretty easy to use and look similar in capability. So, any ideas? ...

Creating threads within the cluster

Hi, I wish to know is there any way that I can create the threads on other nodes without starting the process on the nodes. For example :- lets say I have cluster of 5 nodes I am running an application on node1. Which creates 5 threads on I want the threads not to be created in the same system but across the cluster lets say 1 node 1 t...

OpenMP: omp pararallel vs. omp parallel for?

I am a newbie to OpenMP (I began using it today) What is the difference between these two? [A] #pragma omp parallel { #pragma omp for for(1...100) { } } [B] #pragma omp parallel for for(1..100) { } Thanks in advance! ...

Non-trivial private data in Fortran90 OpenMP

I have a section of a Fortran90 program that should be parallelized with OpenMP. !$omp parallel num_threads(8) & !$omp private(j, s, prop_states) & !$omp firstprivate(targets, pulses) ! ... modify something in pulses. targets(s)%ham contains pointers to ! elements of pulses ... do s = 1, n_systems prop_states(s) = targets(s)%...

OpenMP in Visual Studio 2005

I am attempting to use OpenMP to create a parallel for loop in Visual Studio 2005 Professional. I have included omp.h and specified the /openmp compiler flag. However, I cannot get even the simplest parallel for loop to compile. #pragma omp parallel for for ( int i = 0; i < 10; ++i ) { int a = i + i; } The above produces Compiler ...

Parallel, but slower

I'm using monte carlo method to calculate pi and do a basic experience with parallel programming and openmp the problem is that when i use 1 thread, x iterations, always runs faster than n thread, x iterations. Can anyone tell me why? For example the code runs like this "a.out 1 1000000", where 1 is threads and 1000000 the iterations ...

parallelizing code using openmp

Hi, The function below contains nested for loops. There are 3 of them. I have given the whole function below for easy understanding. I want to parallelize the code in the innermost for loop as it takes maximum CPU time. Then i can think about outer 2 for loops. I can see dependencies and internal inline functions in the innermost for loo...

How to parllelize this, using OPENMP sections

Hi, I have this function which i want to parallelize using openmp sections. I broke the function into various sections and applied #pragma omp sections but it gives segmentation fault. Can somebody please explain why and a solution to it. Should i use some clause with sections. Which one and how please. /*! ****************************...

how to export visual studio project to qt?

Hi, I wonder how can I export a Visual Studio C++ project to qt? I am using openCV and openMP so I would like to know about setting this libraries in qt. Thank you very much. ...

AMD multi-core programming

I want to start to write applications(C++) that will utilize the additional cores to execute portions of the code that have a need to perform lots of calculations and whose computations are independent of each other. I have the following processor : x64 Family 15 Model 104 Stepping 2 Authentic AMD ~1900 Mhz running on Windows Vista Home...

Dependency on VCOMP90.DLL in VS2008 Pro OpenMP project

I have a DLL project in VS 2008 Pro which uses OpenMP. I use /MT as 'code generation' option, because I want all my dependencies statically linked into my DLL, since I do not want to distribute many libraries to my clients - everything shall be included in this one DLL file. The problem is that my resulting DLL still depends on VCOMP90.D...

OpenMP: Causes for heap corruption, anyone?

EDIT: I can run the same program twice, simultaneously without any problem - how can I duplicate this with OpenMP or with some other method? This is the basic framework of the problem. //Defined elsewhere class SomeClass { public: void Function() { // Allocate some memory float *Data; Data = new float[1024]; // Dec...

How to create an `omp parallel for` with synchronization (`barrier`) of all threads in the middle with OpenMP

Hello, I have two fonction, do_step_one(i) and do_step_two(i) for i from 0 to N Currently, I have this (sequential) code ; for(unsigned int i=0; i<N; i++){ do_step_one(i); } for(unsigned int i=0; i<N; i++){ do_step_two(i); } for any step (one or two), each case of N can be done in any order and in parallel, but any step_...

Visual Studio fails to install amd64 OpenMP dlls to WinSXS

I've installed Visual Studio 2008 (and SP1) on a 64-bit copy of Windows 7. When I build and run a 64-bit project it complains that it can't start, and some digging indicates that the 64-bit OpenMP dlls haven't been copied into c:\windows\winsxs. The directories for the 32-bit OpenMP and DebugOpenMP dlls have been created in there correct...