Keep getting CL_INVALID_KERNEL_ARGS on nvidia gpu

Question

I'm using OpenCL on an nvidia GPU and I keep getting CL_INVALID_KERNEL_ARGS when I try to execute a kernel. I've stepped it down to a very simple program:

__kernel void foo(int a, __write_only image2d_t bar)
{
  int 2 coords = {0, get_global_id(0)};
  write_imagef(bar, coords, (float4)a);
}

With the following C program (skipped initialization and error checking bits for brevity)

cl_kernel foo = clCreateKernel(program, "foo", &err);
int a = 42;
clSetKernelArg(foo, 0, sizeof(int), &a);

cl_image_format fmt = {CL_INTENSITY, CL_FLOAT};
cl_mem bar = clCreateImage2D(ctx, CL_MEM_WRITE_ONLY|CL_MEM_ALLOC_HOST_PTR, &fmt, 100, 1, 0, NULL, &err));
clSetKernelArg(foo, 1, sizeof(cl_mem), &bar);

size_t gws[] = {100};
size_t lws[] = {100};
cl_event evt;
clEnqueueNDRangeKernel(queue, foo, 1, NULL, gws, lws, 0, NULL, &evt);
clFinish(queue);

The clEnqueueNDRangeKernel keeps returning CL_INVALID_KERNEL_ARGS. Any ideas?

Answer 1

See https://stackoverflow.com/a/20566270/431528.

How large are the buffer objects you are passing? __constant arguments are allocated from separate memory space and not from global memory so therefore you have probably ran out of constant memory

Check CL_DEVICE_MAX_CONSTANT_BUFFER_SIZE using clGetDeviceInfo to ensure you are not exceeding that size.