问题
Probably extremely simple question here, but I've been searching for it for hours with nothing to show for.
I have this piece of code, I'd like to have a 256-bit (8 uint32) bitstring_gpu as a localmemory pointer in the device:
def Get_Bitstring_GPU_Buffer(ctx, bitstring):
bitstring_gpu = cl.Buffer(ctx, mem_flags.READ_ONLY | mem_flags.COPY_HOST_PTR, hostbuf=bitstring)
return bitstring_gpu
This is later used on a kernel call:
prg.get_active_hard_locations_64bit(queue, (HARD_LOCATIONS,), None, memory_addresses_gpu.data, bitstring_gpu, distances_gpu.data, hash_table_gpu.data ).wait()
... and bitstring is just a random 256-bit bitstring (generated through sha256, then transformed into a numpy array.
def Get_Random_Bitstring():
bitstring = address_space_through_sha256_SDM.get_bitstring(str(random.randrange(2**32-1)))
return bitstring
How can I make bitstring_buf go to fast, local memory?
Related, but different question; here the buffer is being created inside the kernel...
How to create variable sized __local memory in pyopencl?
回答1:
I may have misunderstood the question, but if you want your array placed in local memory - you do that entirely inside the kernel. Your OpenCL code, not your Python code, is responsible for allocating and copying to local memory.
For example, this OpenCL code - inside a kernel - will create an array of 8 local uints and and copy one uint from global memory into the new local array.
__local uint my_local_array[8];
my_local_array[0] = my_global_array[0];
When you want your results back from local memory, you copy from local to global, then copy from global back to the host.
Hope that helps!
来源：https://stackoverflow.com/questions/30271634/pyopencl-how-to-create-a-local-memory-buffer