imx6 opencl zero copy

[liujkian]

Hi, i have a question about the opencl map(clEnqueueMapBuffer ) mechanism. if a opencl host program allocs a block of memory  by itself (such as malloc) not clCreateBuffer,then it calls clEnqueueMapBuffer to map the memory to gpu.can gpu use the mapped memory directly (or DMA )without any data copy (or DMA transfer )to vivante opencl runtime lib or to gpu global memory. Any Tips?thanks

[andre_silva · Accepted solution]

I just checked and cl_mem must be used to allocate memory clEnqueueMapBuffer, there isn´t another way to do fill cpu buffers to be used in gpu, so, zero copies in this case is not possible.

regards,

Andre

[korabelnikov]

Hi,

Is any updates or tips on it? How to make host<->opencl memory access faster?

data transfers take a half of computation time on imx6qp

[arthassin]

I've tried this on imx6. Seems like the buffer is still copied. No any performance improvement was achieved.

[andre_silva]

I´m checking this information and will be back soon with the answer.

[liujkian]

anyone can help me?thanks