Problem compiling logistic_loss CUDA implementation

[jfsantos]

When I try to compile the CUDA kernels, I get this error message:

nvcc -ptx kernels.cu
logistic_loss.impl(31): error: identifier "atomicAdd" is undefined

1 error detected in the compilation of "/tmp/tmpxft_0000722c_00000000-6_kernels.cpp1.ii".
make: *** [kernels.ptx] Error 2

I am using CUDA 4.2 as that's what is available on the cluster I am accessing. Maybe that's too old?

[pluskid]

@jfsantos Hi, atomicAdd for floating point numbers is only supported by devices of compute capability 2.x and higher. See the CUDA document. I'm not very sure what kind of device and CUDA driver version corresponds to compute capability 2.x and higher, but CUDA 4.2 sounds old.

But I think what's more importantly is that cuDNN, the library we used for doing efficient convolution and pooling on GPU, requires a quite recent version of CUDA. I didn't see it mentioned in the official document, but I saw it somewhere people were having some issue using cuDNN on CUDA with version lower than 6.5 (the latest is 6.5).

[jfsantos]

I cannot find info on the minimum requirements for cuDNN, but I will try it on a different cluster that has CUDA 6.0 installed. I will keep you posted on my results, and maybe submit a pull request for updating the docs if you are interested..

[pluskid]

@jfsantos sure! Thank you very much!

[jfsantos]

I was not able to compile the CUDA kernels with CUDA 6.0, so maybe the docs should stay as they are right now (i.e., recommending 6.5).

[pluskid]

@jfsantos Thank you very much for your efforts!