openmp « thread « C Q&A

1. Behavior of omp_get_max_threads in parallel regions    stackoverflow.com

I compile this bit of code on Snow Leopard and linux and I get different results. On Snow leopard, the first call of omp_get_max_threads returns 2, which is my number ...

2. Ordered Parallel code runs slower than single threading. Is there a solution?    stackoverflow.com

#pragma omp parallel for default(none) shared(x) private (y, z, f) ordered
for (i = 0; i < 512; i++) {
    #pragma omp ordered
    for (y = ...

3. Why is my OpenMP implementation slower than a single threaded implementation?    stackoverflow.com

I am learning about OpenMP concurrency, and tried my hand at some existing code I have. In this code, I tried to make all the for loops parallel. However, this seems ...

4. Why is my OpenMP implementation slower than a single threaded implementation? (Followup)    stackoverflow.com

This is a follow up to Why is my OpenMP implementation slower than a single threaded implementation? . I have adhered to the answer provided, and used tasking instead of for ...

5. #pragma omp flush to make exchange data among threads    stackoverflow.com

Hi writing a very simple example on how to use omp flush to exchange data, in a producer-> consumer way,among threads I have found a funny behavior.

int a=-1;
int flag=1;
int count=0;
#pragma omp ...

6. openMP with only one thread running?    stackoverflow.com

I have this code in the main:

int main(int argv, char **argc)
{
   // Get multi-CPU/multi-GPU data
   int num_gpus;
   cudaGetDeviceCount(&num_gpus);
   printf("### Number of host CPUs:\t%d\n", ...

7. How do I ask OpenMP to create threads only once at each run of the program?    stackoverflow.com

I am trying to parallelize a large program that is written by a third-party. I cannot disclose the code, but I will try and give the closest example of what I ...