GPU error with the example

[nwalet]

I have had some real issues with my own custom interactions and CUDA, so I have returned to the standard example (CUDA with LJ and Verlet) from the documentation. That fails as well:

ERROR: LoadError: GPU broadcast resulted in non-concrete element type Union{}.
This probably means that the function you are broadcasting contains an error or type instability.
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:35

I would hope that would run?
environment:

CUDA.versioninfo()
CUDA runtime 11.8, artifact installation
CUDA driver 12.3
NVIDIA driver 545.23.8

CUDA libraries: 
- CUBLAS: 11.11.3
- CURAND: 10.3.0
- CUFFT: 10.9.0
- CUSOLVER: 11.4.1
- CUSPARSE: 11.7.5
- CUPTI: 18.0.0
- NVML: 12.0.0+545.23.8

Julia packages: 
- CUDA: 4.4.1
- CUDA_Driver_jll: 0.5.0+1
- CUDA_Runtime_jll: 0.6.0+0

Toolchain:
- Julia: 1.9.3
- LLVM: 14.0.6
- PTX ISA support: 3.2, 4.0, 4.1, 4.2, 4.3, 5.0, 6.0, 6.1, 6.3, 6.4, 6.5, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5
- Device capability support: sm_37, sm_50, sm_52, sm_53, sm_60, sm_61, sm_62, sm_70, sm_72, sm_75, sm_80, sm_86

1 device:
  0: Quadro P400 (sm_61, 1.772 GiB / 2.000 GiB available)

With my own interaction it gets rather worse, and I get messages like
Reason: unsupported call through a literal pointer (call to ijl_alloc_string)
and
Reason: unsupported dynamic function invocation (call to print
but I can probably work those out once I have a working example--feels like some of my "smart" coding doesn't work with CUDA compilation.
Niels

[jgreener64]

Could you paste the exact example code that you tried? The versions look okay.

[nwalet]

using Molly
using CUDA

n_atoms = 100
atom_mass = 10.0f0u"g/mol"
boundary = CubicBoundary(2.0f0u"nm")
temp = 100.0f0u"K"
atoms = CuArray([Atom(mass=atom_mass, σ=0.3f0u"nm", ϵ=0.2f0u"kJ * mol^-1") for i in 1:n_atoms])
coords = CuArray(place_atoms(n_atoms, boundary; min_dist=0.3u"nm"))
velocities = CuArray([random_velocity(atom_mass, temp) for i in 1:n_atoms])
#simulator = VelocityVerlet(dt=0.002f0u"ps")
simulator = NoseHoover(;dt=0.002f0u"ps",temperature="10K",)

sys = System(
    atoms=atoms,
    coords=coords,
    boundary=boundary,
    velocities=velocities,
    pairwise_inters=(LennardJones(),),
    loggers=(
        temp=TemperatureLogger(typeof(1.0f0u"K"), 10),
        coords=CoordinateLogger(typeof(1.0f0u"nm"), 10),
    ),
)

simulate!(deepcopy(sys), simulator, 20) # Compile function
simulate!(sys, simulator, 1_000)

[jgreener64]

Works for me with the temperature="10K" typo changed to temperature=10u"K".

Could you give your package versions with ]st, the output of versioninfo(), and the full stacktrace?

Does CUDA.jl work for you in general, e.g. is CuArray(rand(3, 3)) .+ CuArray(rand(3, 3)) okay?

[nwalet]

Thanks Joe,
That is useful to know--tried it on another computer, and it works there, so clearly the other one needs some additional CUDA goodies installed.
Onwards to debugging my "own" potential.