Hello, I have some doubt about the zerocopy function.
Suppose the code is something like below:
What I want to do is to zerocopy a pre-aligned memory M and transfer to a opencl function OpenCL_Foo, and after the calculation save the result to M.
Do I still get access to M(with the right calculation result from opencl function) even after the OpenCL_Foo ends?
#or do I need to memcopy it?
Thank you in advance for you kindly help.
////////////////////////////////////////////
void OpenCL_Foo(float*array_as_output,int SIZE, float*array_as_output_cpy)
{//Some opencl process
...
//set the parameter array as output buffer of some calculation.
cl_mem buffer_out = clCreateBuffer(ctx, CL_MEM_WRITE | CL_MEM_USE_HOST_PTR,SIZE * sizeof(cl_float), array_as_output, &err);
...
//is this part below necessay? or can I just access array_as_output outside this function?
/*
void* ptr1 = clEnqueueMapBuffer(queue, buffer_out , CL_TRUE, CL_MAP_READ, 0, SIZE*sizeof(float), 0, NULL, NULL, NULL);
memcpy(array_as_output_cpy,ptr1,SIZE*sizeof(float));
err=clEnqueueUnmapMemObject(queue,buffer_out , ptr1, 0, NULL, NULL);
*/
}// end of OpenCL_Foo
////////////////////////////////////////////
int main()
{
int SIZE = 1024;
float*array_as_output;
float*array_as_output_cpy;
posix_memalign((void**)&array_as_output,4096,SIZE * sizeof (cl_float));
posix_memalign((void**)&array_as_output_cpy,4096,SIZE * sizeof (cl_float));
OpenCL_Foo(array_as_output,SIZE,array_as_output_cpy);
...
}//end of main