# Disable all GPU support when using Lux

**URL:** <https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076>\
**Category:** GPU\
**Created:** [June 8, 2023, 10:36pm UTC](https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076 "2023-06-08T22:36:42Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![contradict](https://avatars.discourse-cdn.com/v4/letter/c/ac91a4/32.png) [@contradict](https://discourse.julialang.org/u/contradict)\
**Post date:** [June 8, 2023, 10:36pm UTC](https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076/1 "2023-06-08T22:36:42Z")

</div>

I have an old GPU which is no longer supported and would like to run Lux anyway using just the CPU.

```julia
$ nvidia-smi -L
GPU 0: NVIDIA GeForce GTX 680 (UUID: GPU-49fc79e3-b888-22fe-dc46-f3233d654e1b)

```

I tried the suggestion from the documentation:

```julia
$ CUDA_VISIBLE_DEVICES='-1' julia --project
               _
   _ _ _(_)_ | Documentation: https://docs.julialang.org
  (_) | (_) (_) |
   _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` | |
  | | |_| | | | (_| | | Version 1.9.1 (2023-06-07)
 _/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |

julia> using Lux

```

> **This fails with several errors**
>
> ```julia
> [Info: Precompiling Lux [b2108857-7c20-44ae-9111-449ecde12c47]
> ERROR: LoadError: InitError: CUDA error (code 101, CUDA_ERROR_INVALID_DEVICE)
> Stacktrace:
> [1] throw_api_error(res::CUDA.cudaError_enum)
> @ CUDA ~/.julia/packages/CUDA/pCcGc/lib/cudadrv/libcuda.jl:27
> [2] check
> @ ~/.julia/packages/CUDA/pCcGc/lib/cudadrv/libcuda.jl:34 [inlined]
> [3] runtime_version()
> @ CUDA ~/.julia/packages/CUDA/pCcGc/lib/cudadrv/version.jl:39
> [4] __init__ ()
> @ CUDA ~/.julia/packages/CUDA/pCcGc/src/initialization.jl:102
> [5] register_restored_modules(sv::Core.SimpleVector, pkg::Base.PkgId, path::String)
> @ Base ./loading.jl:1115
> [6] _include_from_serialized(pkg::Base.PkgId, path::String, ocachepath::String, depmods::Vector{Any})
> @ Base ./loading.jl:1061
> [7] _require_search_from_serialized(pkg::Base.PkgId, sourcepath::String, build_id::UInt128)
> @ Base ./loading.jl:1506
> [8] _require(pkg::Base.PkgId, env::String)
> @ Base ./loading.jl:1783
> [9] _require_prelocked(uuidkey::Base.PkgId, env::String)
> @ Base ./loading.jl:1660
> [10] macro expansion
> @ ./loading.jl:1648 [inlined]
> [11] macro expansion
> @ ./lock.jl:267 [inlined]
> [12] require(into::Module, mod::Symbol)
> @ Base ./loading.jl:1611
> [13] include
> @ ./Base.jl:457 [inlined]
> [14] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{String}, dl_load_path::Vector{String}, load_path::Vector{String}, concrete_deps::Vector{Pair{Base.PkgId, UInt128}}, source::String)
> @ Base ./loading.jl:2045
> [15] top-level scope
> @ stdin:3
> during initialization of module CUDA
> in expression starting at /home/user/.julia/packages/LuxCUDA/CsMat/src/LuxCUDA.jl:1
> in expression starting at stdin:3
> ERROR: LoadError: Failed to precompile LuxCUDA [d0bbae9a-e099-4d5b-a835-1c6931763bda] to "/home/user/.julia/compiled/v1.9/LuxCUDA/jl_RobAW1".
> Stacktrace:
> [1] error(s::String)
> @ Base ./error.jl:35
> [2] compilecache(pkg::Base.PkgId, path::String, internal_stderr::IO, internal_stdout::IO, keep_loaded_modules::Bool)
> @ Base ./loading.jl:2296
> [3] compilecache
> @ ./loading.jl:2163 [inlined]
> [4] _require(pkg::Base.PkgId, env::String)
> @ Base ./loading.jl:1805
> [5] _require_prelocked(uuidkey::Base.PkgId, env::String)
> @ Base ./loading.jl:1660
> [6] macro expansion
> @ ./loading.jl:1648 [inlined]
> [7] macro expansion
> @ ./lock.jl:267 [inlined]
> [8] require(into::Module, mod::Symbol)
> @ Base ./loading.jl:1611
> [9] include
> @ ./Base.jl:457 [inlined]
> [10] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{String}, dl_load_path::Vector{String}, load_path::Vector{String}, concrete_deps::Vector{Pair{Base.PkgId, UInt128}}, source::Nothing)
> @ Base ./loading.jl:2045
> [11] top-level scope
> @ stdin:3
> in expression starting at /home/user/.julia/packages/Lux/71GtU/src/Lux.jl:1
> in expression starting at stdin:3
> ERROR: Failed to precompile Lux [b2108857-7c20-44ae-9111-449ecde12c47] to "/home/user/.julia/compiled/v1.9/Lux/jl_SLZBwA".
> Stacktrace:
> [1] error(s::String)
> @ Base ./error.jl:35
> [2] compilecache(pkg::Base.PkgId, path::String, internal_stderr::IO, internal_stdout::IO, keep_loaded_modules::Bool)
> @ Base ./loading.jl:2296
> [3] compilecache
> @ ./loading.jl:2163 [inlined]
> [4] _require(pkg::Base.PkgId, env::String)
> @ Base ./loading.jl:1805
> [5] _require_prelocked(uuidkey::Base.PkgId, env::String)
> @ Base ./loading.jl:1660
> [6] macro expansion
> @ ./loading.jl:1648 [inlined]
> [7] macro expansion
> @ ./lock.jl:267 [inlined]
> [8] require(into::Module, mod::Symbol)
> @ Base ./loading.jl:1611
> 
> ```

Is there a way to disable loading of `CUDA` alltogether?

---

<div class="post-metadata">

**Author:** ![maleadt](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/maleadt/32/10097_2.png) [@maleadt](https://discourse.julialang.org/u/maleadt)\
**Post date:** [June 9, 2023, 5:44am UTC](https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076/2 "2023-06-09T05:44:18Z")

</div>

You should set `CUDA_VISIBLE_DEVICES` to an empty string, not to `-1`.

However, it’d be better if Lux left that up to the user, by relying on Requires or package extensions. In that case, you’d choose whether to install CUDA.jl or not, rather than it getting auto-loaded by Lux.

---

<div class="post-metadata">

**Author:** ![avikpal](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/avikpal/32/6550_2.png) [@avikpal](https://discourse.julialang.org/u/avikpal)\
**Post date:** [June 9, 2023, 3:15pm UTC](https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076/3 "2023-06-09T15:15:27Z")

</div>

I agree. I have been working on migrating Lux to rely on accelerators via Pkg extensions. Most of the things are already in place, but we need some additional features to be finalized before cutting a breaking release.

---

<div class="post-metadata">

**Author:** ![contradict](https://avatars.discourse-cdn.com/v4/letter/c/ac91a4/32.png) [@contradict](https://discourse.julialang.org/u/contradict)\
**Post date:** [June 9, 2023, 3:44pm UTC](https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076/4 "2023-06-09T15:44:05Z")

</div>

I get the same error with an empty string.

```julia
$ CUDA_VISIBLE_DEVICES='' julia --project
               _
   _ _ _(_)_ | Documentation: https://docs.julialang.org
  (_) | (_) (_) |
   _ _ _| |_ __ _ | Type "?" for help, "]?" for Pkg help.
  | | | | | | |/ _` | |
  | | |_| | | | (_| | | Version 1.9.1 (2023-06-07)
 _/ |\ __'_|_|_|\__'_| | Official https://julialang.org/ release
|__/ |

(cuda) pkg> st
Status `~/Desktop/Julia/cuda/Project.toml`
  [052768ef] CUDA v4.3.2

julia> using CUDA
ERROR: InitError: CUDA error (code 101, CUDA_ERROR_INVALID_DEVICE)
Stacktrace:
  [1] throw_api_error(res::CUDA.cudaError_enum)
    @ CUDA ~/.julia/packages/CUDA/pCcGc/lib/cudadrv/libcuda.jl:27
  [2] check
    @ ~/.julia/packages/CUDA/pCcGc/lib/cudadrv/libcuda.jl:34 [inlined]
  [3] runtime_version()
    @ CUDA ~/.julia/packages/CUDA/pCcGc/lib/cudadrv/version.jl:39
  [4] __init__ ()
    @ CUDA ~/.julia/packages/CUDA/pCcGc/src/initialization.jl:102
  [5] register_restored_modules(sv::Core.SimpleVector, pkg::Base.PkgId, path::String)
    @ Base ./loading.jl:1115
  [6] _include_from_serialized(pkg::Base.PkgId, path::String, ocachepath::String, depmods::Vector{Any})
    @ Base ./loading.jl:1061
  [7] _require_search_from_serialized(pkg::Base.PkgId, sourcepath::String, build_id::UInt128)
    @ Base ./loading.jl:1506
  [8] _require(pkg::Base.PkgId, env::String)
    @ Base ./loading.jl:1783
  [9] _require_prelocked(uuidkey::Base.PkgId, env::String)
    @ Base ./loading.jl:1660
 [10] macro expansion
    @ ./loading.jl:1648 [inlined]
 [11] macro expansion
    @ ./lock.jl:267 [inlined]
 [12] require(into::Module, mod::Symbol)
    @ Base ./loading.jl:1611
during initialization of module CUDA

```

Edit:

I think this must be a CUDA (not CUDA.jl) problem or something obnoxiously specific to my machine. According to the [CUDA documentation](https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html?highlight=CUDA_VISIBLE_DEVICES#cuda-environment-variables) either empty string or invalid index should disable all GPUs.

---

<div class="post-metadata">

**Author:** ![maleadt](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/maleadt/32/10097_2.png) [@maleadt](https://discourse.julialang.org/u/maleadt)\
**Post date:** [June 10, 2023, 10:00am UTC](https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076/5 "2023-06-10T10:00:26Z")

</div>

That’s curious. I’ll have a look.

---

<div class="post-metadata">

**Author:** ![avikpal](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/avikpal/32/6550_2.png) [@avikpal](https://discourse.julialang.org/u/avikpal)\
**Post date:** [July 2, 2023, 2:26am UTC](https://discourse.julialang.org/t/disable-all-gpu-support-when-using-lux/100076/6 "2023-07-02T02:26:26Z")

</div>

`Lux#main` (v0.5) has dropped direct dependencies on all GPU backends. I will tag a release within a few weeks, just testing out edge cases if we missed any. See [GPU Management - Lux.jl](https://lux.csail.mit.edu/dev/manual/gpu_management/)