Hi,
I would like to confirm whether CL_MEM_USE_HOST_PTR has extra overhead, such as memory copy, on Mali G72.
According to ARM OpenCL Optimization Guide, using CL_MEM_USE_HOST_PTR is discouraged.
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.100614_0300_00_en/index.html
"8.3.3 Do not create buffers with CL_MEM_USE_HOST_PTR if possible"
Thanks,
Jeff
Hi Jeff,
CL_MEM_USE_HOST_PTR will result in copies being performed during map/unmap operations (unless the host_ptr passed in has been obtained with clSVMAlloc). To create a buffer that wraps memory that hasn't been obtained from the OpenCL runtime without having to pay the cost of copies, I recommend having a look at our memory import extension: https://www.khronos.org/registry/OpenCL/extensions/arm/cl_arm_import_memory.txt
Regards,
Kévin