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cudathrust

Thrust device management and kernel

I'm using Thrust in my current project so I don't have to write a device_vector abstraction or (segmented) scan kernels myself.

So far I have done all of my work using thrust abstractions, but for simple kernels or kernels that don't translate easily to the for_each or transform abstractions I'd prefer at some point to write my own kernels instead.

So my question is: Can I through Thrust (or perhaps CUDA) ask which device is currently being used and what properties it has (max block size, max shared memory, all that stuff)?

If I can't get the current device, is there then some way for me to get thrust to calculate the kernel dimensions if I provide the kernel registers and shared memory requirements?

Solution

  • You can query the current device with CUDA. See the CUDA documentation on device management. Look for cudaGetDevice(), cudaSetDevice(), cudaGetDeviceProperties(), etc.

    Thrust has no notion of device management currently. I'm not sure what you mean by "get thrust to calculate the kernel dimensions", but if you are looking to determine grid dimensions for launching your custom kernel, then you need to do that on your own. It can help to query the properties of the kernel with cudaFuncGetAttributes(), which is what Thrust uses.