CODEWITHSUNDEEP
c++memoryparallel-processingopencl
Philipp Braun
Philipp Braun

Reputation: 1573

clEnqueueNDRangeKernel fills up entire memory

I am currently trying to write an OpenCL application doing some memory intensive calculations. To track the progress of all the calculations I created a for loop which creates different kernel groups. Unfortunately, the calculation fills up my whole memory. My guess is that the kernels are not done executing before the next heap is added.

for (unsigned long i=1; i<maxGlobalThreads; i+=1000000) {

    // Calculating Offset
    size_t temp = 1000000;
    size_t offset = 0;
    if (i>1000000) {
        offset = i-1000000;
    }

    cl_event tmp;

    clEnqueueNDRangeKernel(command_queue, kernel, 1, &offset, &temp, NULL, NULL, 0, &tmp);

    // Wait until Threads finished (-- not working)
    clWaitForEvents(1, &tmp);

    // Copy results from memory buffer
    int *res = (int*)malloc(64*sizeof(int));
    int *indexNum = (int*)malloc(14*sizeof(int));
    err = clEnqueueReadBuffer(command_queue, foundCombiMem, CL_TRUE, 0, 64*sizeof(int), res, 0, NULL, NULL);
    err = clEnqueueReadBuffer(command_queue, indexNumMem, CL_TRUE, 0, 14*sizeof(int), indexNum, 0, NULL, NULL);

    // Calculate Time for 1000000 checked combinations
    diff = clock() - start;
    double msec = diff * 1000 / CLOCKS_PER_SEC;
    printf("%f\n", (msec/(i*1000000))*1000000);

    [ ... ]
}

Memory Stats

Upvotes: 0

Views: 224

Answers (2)

Ingo
Ingo

Reputation: 5381

In this case the best you can do is to add 

clFinish(CommandQueue);

after 

clEnqueueNDRangeKernel

Upvotes: 0

Lubo Antonov
Lubo Antonov

Reputation: 2318

You are doing to mallocs that are never freed on each iteration of the loop. This is why you are running out of memory.

Also, your loop is using an unsigned int variable, which could be a problem depending on the value of maxGloablThreads.

Upvotes: 2

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