Zero-copy with pre-allocated memory

Discussion created by ebaron on May 20, 2011
Latest reply on Jun 7, 2011 by himanshu.gautam
on Fusion APU


I'm experimenting with an E-350 APU and trying to minimize any CPU -> GPU transfer time. From Chapter 4 of the programming guide, I see zero-copy access is possible using CL_MEM_ALLOC_HOST_PTR. This will allow me to create a buffer that the device can access without copying, but in my case I have data already in memory and I would have to copy it to this zero-copy buffer.

Is there any way to create a buffer using an existing host pointer, such as with CL_MEM_USE_HOST_PTR, and have the OpenCL runtime pin the pages from this buffer and make them usable by the device?