Re: Have GPGPU support in guix?

[Ludovic Courtès]

Hi,

Fis Trivial <address@hidden> skribis:

>>> However, I wanted to manage all of these with guix so that we can have a
>>> unified dependency tree. Currently there are a few options for OpenCL
>>> runtime. Namely, beignet, neo from Intel, ROCm stack from AMD, the POCL
>>> project and the implementation in mesa.
>>> 
>>> I tried to package beignet (an old OpenCL runtime from Intel) but it
>>> wasn't successful due to failed tests (it failed from recognizing
>>> device).
>>> https://github.com/trivialfis/guixpkgs/blob/master/opencl.scm
>>
>> Regarding failed tests, I think that tests that expect GPU devices to be
>> able are likely to fail: it could be that the relevant /dev nodes are
>> inaccessible to the build users, or, more importantly, it could be that
>> we’re building on a GPU-less machine such as our build farm.  So these
>> tests would have to be skipped.
>
> I think we might need a better scheme other than skipping tests to
> verify the usability of these packages. If we skip tests for OpenCL
> runtime, then all the other packages (I promise it will be A LOT) that
> depend on it will need to skip their tests, since they won't run without
> a proper runtime, resulting in a whole tree of untested packages. And
> these thing break easily, due to the fact that they usually rely on
> specific version of Clang and LLVM, and many of them still in heavy
> development stage.

Are you sure?  What I would expect is that packages would be able to use
the OpenCL run-time, they’d even be able to run OpenCL code as part of
their tests, only it would run on the main CPU instead of on GPUs, as if
the machine had no usable GPUs.

Does that make sense?

Thanks,
Ludo’.