On 06/20/2018 03:15 PM, Tom de Vries wrote:
> On 06/20/2018 11:59 PM, Cesar Philippidis wrote:
>> Now it follows the formula contained in
>> the "CUDA Occupancy Calculator" spreadsheet that's distributed with CUDA.
>
> Any reason we're not using the cuda runtime functions to get the
> occupancy (see PR85590 - [nvptx, libgomp, openacc] Use cuda runtime fns
> to determine launch configuration in nvptx ) ?
There are two reasons:
1) cuda_occupancy.h depends on the CUDA runtime to extract the device
properties instead of the CUDA driver API. However, we can always
teach libgomp how to populate the cudaDeviceProp struct using the
driver API.
2) CUDA is not always present on the build host, and that's why
libgomp maintains its own cuda.h. So at the very least, this
functionality would be good to have in libgomp as a fallback
implementation; its not good to have program fail due to
insufficient hardware resources errors when it is avoidable.
Cesar
