...

For this example, we're going to be using the jupyter/datascience-notebook (external site) Docker image. It provides a Conda environment with a large collection of common Python packages (including NumPy, SciPy, Pandas, Scikit-learn, Bokeh and Matplotlib), an R environment (with the tidyverse (external site) packages), and a Julia environment. All of these are accessible via a Jupyter notebook server.

This Docker image ships with a startup script that allows for a number of runtime options to be specified. Most of these are specific to running a container using Docker; we will focus on how to run this container using  Singularity.

The datascience-notebook image has a default user, jovyan, and it assumes that you will be able to write to /home/jovyan. When you run a Docker container via Singularity, you will be running as your Pawsey username inside the container, so we won't be able to write to /home/jovyan. Instead, we can mount a specific directory (on Pawsey's filesystems) into the container at /home/jovyan. This will allow our Jupyter server to do things like save notebooks and write checkpoint files, and those will persist on Pawsey's filesystem after the container has stopped.

...

# key GPU library
from numba import cuda
import numpy as np

# define some kernels
@cuda.jit
def add_kernel(x, y, out):
    idx = cuda.grid(1)
    out[idx] = x[idx] + y[idx]

n = 4096
x = np.arange(n).astype(np.int32) # [0...4095] on the host
y = np.ones_like(x)               # [1...1] on the host
out = np.zeros_like(x)

# cuda commands to copy memory to the device 
d_x = cuda.to_device(x)
d_y = cuda.to_device(y)
d_out = cuda.to_device(out)

# run kernel
threads_per_block = 128
blocks_per_grid = 32
add_kernel[blocks_per_grid, threads_per_block](d_x, d_y, d_out)
cuda.synchronize()

# output result 
print(d_out.copy_to_host()) # Should be [1...4096]

External links

• DockerHub
• For information about runtime options supported by the startup script in the Jupyter image, see Common Features in the Jupyter Docker Stacks documentation
• The Rocker Project ("Docker Containers for the R Environment")