Introduction⌗

JAX is this rad library from Google research that acts as a Domain Specific Language (DSL) for machine learning, similar to how Halide-lang is a DSL for image processing. It’s pretty hard to get it working properly on Ubuntu since there are a lot of easy pitfalls. However, this guide will get you up and running on the latest bleeding edge of everything on Ubuntu 22.04.

First remove previous Nvidia drivers⌗

There are two normal ways to install Nvidia drivers on Ubuntu that are familiar (1) Download the run-file from Ubuntu and manually install and (2) Use the nvidia-driver-515 package.

To uninstall the runfile version:

sudo bash NVIDIA-Linux-x86_64-XXX.XX.run --uninstall

To uninstall the Ubuntu package version:

sudo apt remove nvidia-driver-*
sudo apt autoremove

The autoremove is important to get rid of some files we need to overwrite next with symlinks.

Install cuda package⌗

Instructions are here: https://developer.nvidia.com/cuda-downloads?target_os=Linux&target_arch=x86_64&Distribution=Ubuntu&target_version=22.04&target_type=deb_network

wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2204/x86_64/cuda-keyring_1.0-1_all.deb
sudo dpkg -i cuda-keyring_1.0-1_all.deb
sudo apt-get update
sudo apt-get -y install cuda cuda-11-8
sudo update-alternatives --set cuda /usr/local/cuda-11.8
sudo reboot now

Check which version of CUDA is installed:

(base) catid@nuc:~$ nvidia-smi
Mon Oct 17 00:17:59 2022       
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 520.61.05    Driver Version: 520.61.05    CUDA Version: 11.8     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|                               |                      |               MIG M. |
|===============================+======================+======================|
|   0  NVIDIA GeForce ...  On   | 00000000:01:00.0 Off |                  N/A |
|  0%   54C    P8    26W / 350W |      1MiB / 24576MiB |      0%      Default |
|                               |                      |                  N/A |
+-------------------------------+----------------------+----------------------+
                                                                               
+-----------------------------------------------------------------------------+
| Processes:                                                                  |
|  GPU   GI   CI        PID   Type   Process name                  GPU Memory |
|        ID   ID                                                   Usage      |
|=============================================================================|
|  No running processes found                                                 |
+-----------------------------------------------------------------------------+

You can see version 11.8 of CUDA is installed. Since we ran the up-date-alternatives command, we can now use the nvcc compiler.

(base) catid@nuc:~$ nvcc --version
nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2022 NVIDIA Corporation
Built on Wed_Sep_21_10:33:58_PDT_2022
Cuda compilation tools, release 11.8, V11.8.89
Build cuda_11.8.r11.8/compiler.31833905_0

Test CUDA installation⌗

git clone https://github.com/NVIDIA/cuda-samples.git
cd ./cuda-samples/Samples/1_Utilities/deviceQuery
vi Makefile

Set the CUDA_PATH= line to install path of CUDA. Example:

CUDA_PATH ?= /usr/local/cuda-11.8

This path is important to note for when we install JAX later.

Build and run the tool:

make
./deviceQuery
(base) catid@nuc:~/cuda-samples/Samples/1_Utilities/deviceQuery$ ./deviceQuery 
./deviceQuery Starting...

 CUDA Device Query (Runtime API) version (CUDART static linking)

Detected 1 CUDA Capable device(s)

Device 0: "NVIDIA GeForce RTX 3090"
  CUDA Driver Version / Runtime Version          11.8 / 11.8
  CUDA Capability Major/Minor version number:    8.6
  Total amount of global memory:                 24268 MBytes (25447170048 bytes)
  (082) Multiprocessors, (128) CUDA Cores/MP:    10496 CUDA Cores
  GPU Max Clock rate:                            1725 MHz (1.73 GHz)
  Memory Clock rate:                             9751 Mhz
  Memory Bus Width:                              384-bit
  L2 Cache Size:                                 6291456 bytes
  Maximum Texture Dimension Size (x,y,z)         1D=(131072), 2D=(131072, 65536), 3D=(16384, 16384, 16384)
  Maximum Layered 1D Texture Size, (num) layers  1D=(32768), 2048 layers
  Maximum Layered 2D Texture Size, (num) layers  2D=(32768, 32768), 2048 layers
  Total amount of constant memory:               65536 bytes
  Total amount of shared memory per block:       49152 bytes
  Total shared memory per multiprocessor:        102400 bytes
  Total number of registers available per block: 65536
  Warp size:                                     32
  Maximum number of threads per multiprocessor:  1536
  Maximum number of threads per block:           1024
  Max dimension size of a thread block (x,y,z): (1024, 1024, 64)
  Max dimension size of a grid size    (x,y,z): (2147483647, 65535, 65535)
  Maximum memory pitch:                          2147483647 bytes
  Texture alignment:                             512 bytes
  Concurrent copy and kernel execution:          Yes with 2 copy engine(s)
  Run time limit on kernels:                     No
  Integrated GPU sharing Host Memory:            No
  Support host page-locked memory mapping:       Yes
  Alignment requirement for Surfaces:            Yes
  Device has ECC support:                        Disabled
  Device supports Unified Addressing (UVA):      Yes
  Device supports Managed Memory:                Yes
  Device supports Compute Preemption:            Yes
  Supports Cooperative Kernel Launch:            Yes
  Supports MultiDevice Co-op Kernel Launch:      Yes
  Device PCI Domain ID / Bus ID / location ID:   0 / 1 / 0
  Compute Mode:
     < Default (multiple host threads can use ::cudaSetDevice() with device simultaneously) >

deviceQuery, CUDA Driver = CUDART, CUDA Driver Version = 11.8, CUDA Runtime Version = 11.8, NumDevs = 1
Result = PASS

Install cuDNN⌗

Download the .deb file from https://developer.nvidia.com/rdp/cudnn-download

This requires an Nvidia developer account.

I downloaded and installed this file:

sudo dpkg -i cudnn-local-repo-ubuntu2204-8.6.0.163_1.0-1_amd64.deb
sudo cp /var/cudnn-local-repo-ubuntu2204-8.6.0.163/cudnn-local-FAED14DD-keyring.gpg /usr/share/keyrings/
sudo apt install libcudnn8-dev

This seems to put the cudnn library headers/files under /usr.

Easy install jax⌗

This seems to work fine:

pip install --upgrade "jax[cuda]" -f https://storage.googleapis.com/jax-releases/jax_cuda_releases.html

Manual build and install jaxlib⌗

These steps are from https://jax.readthedocs.io/en/latest/developer.html#building-from-source

Build jaxlib:

git clone https://github.com/google/jax
cd jax
sudo apt install g++ python3 python3-dev
pip install numpy wheel
python build/build.py --enable_cuda --cuda_path /usr/local/cuda-11.8 --cudnn_path /usr

The build takes about 30 minutes on a modern processor. Finally, time to install!

pip install --upgrade pip
pip install dist/*.whl
pip install -e .  # installs jax

Test JAX⌗

Write a simple test Python script from the Jax repo https://github.com/google/jax

from jax import grad
import jax.numpy as jnp

def tanh(x):  # Define a function
  y = jnp.exp(-2.0 * x)
  return (1.0 - y) / (1.0 + y)

grad_tanh = grad(tanh)  # Obtain its gradient function
print(grad_tanh(1.0))   # Evaluate it at x = 1.0
# prints 0.4199743

Run the test:

(base) catid@nuc:~$ python temp.py
0.4199743

I used tmux and watch nvidia-smi in a second pane to verify that the GPU was actually getting used for this script.