Tutorials/Accelerated Python: Fixes and improvements to memory spaces, asynchrony, and kernel authoring notebooks by brycelelbach · Pull Request #148 · NVIDIA/accelerated-computing-hub

brycelelbach · 2026-03-03T18:19:39Z

Summary

Fixes and improvements across four Accelerated Python tutorial notebooks (and their solutions): Memory Spaces, Asynchrony, Copy Kernel Authoring, and Book Histogram Kernel Authoring.

Memory Spaces (Power Iteration)

Fix benchmark to compare CPU wall-clock times for both host and device, and revert to using the same input matrix for both.
Unify benchmark reporting to use milliseconds with mean ± relative stdev format.
Remove inline benchmarking from sections 3 and 4.
Separate eigvals into its own cell, fix capitalization, and restore eigvals timing.
Remove outdated note about cupy.linalg.eigvals not being implemented.
Remove unnecessary isinstance check before cp.asarray().
Rename estimate_device_exercise / generate_device_exercise back to estimate_device / generate_device.
Re-add checkpoint I/O to power iteration.

Asynchrony (Power Iteration)

Fix compute step NVTX annotations with accurate step ranges and per-step regions.
Limit warmup calls to 1 step to avoid unnecessary computation.

Cross-Cutting (Memory Spaces + Asynchrony)

Unify benchmark reporting to use milliseconds with mean ± relative stdev format.
Fix typos in example usage of cupyx.profiler.profile and NVTX.

Kernel Authoring (Copy)

Add configurable correctness check to the copy kernel launch function.
Add correctness check cell before profiling copy_blocked kernel.
Add output mode to copy kernel scripts to print problem size and dtype.
Apply title, TOC, section header, and text updates to solution notebooks.

Kernel Authoring (Book Histogram)

Improve plot formatting with titles and dataset size display.
Display dataset size in megabytes instead of bytes.
Apply title, TOC, section header, and text updates to solution notebooks.

copy-pr-bot · 2026-03-03T18:19:44Z

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github-actions · 2026-03-03T18:20:14Z

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brycelelbach · 2026-03-03T18:21:37Z

/ok to test e9e650d

github-actions · 2026-03-03T20:46:02Z

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brycelelbach · 2026-03-03T22:44:41Z

/ok to test eab9896

… plot formatting, add title and dataset size display.

…ctness check to copy kernel launch function.

… dataset size in megabytes instead of bytes. Made-with: Cursor

…cell before profiling copy_blocked kernel. Add a verification cell that runs the script immediately after the %%writefile cell, matching the pattern used in the book histogram notebook. Made-with: Cursor

…age of cpyx.profiler.profile and NVTX.

…ion header, and text updates to solution notebooks. These changes were made to the exercise notebooks in 2f5c4fc but were not applied to the corresponding solution notebooks. Made-with: Cursor

…y kernel scripts to print problem size and dtype. Made-with: Cursor

…power iteration. The savetxt checkpoint I/O was removed from the 05 memory spaces notebooks in 2f5c4fc. This I/O is needed to set up the narrative for Notebook 06 (Asynchrony), whose baseline is the synchronous device-to-host copy + file write pattern introduced here. Made-with: Cursor

…ance check before cp.asarray(). The isinstance(A, np.ndarray) guard added in 2f5c4fc is unnecessary because cp.asarray() already handles both cases: it copies a host array to the GPU, and is a no-op when the array is already on the GPU. Teaching users to call cp.asarray() unconditionally is the intended lesson. Made-with: Cursor

…ercise and generate_device_exercise back to estimate_device and generate_device. The _exercise suffix was added in 2f5c4fc but breaks the naming symmetry with estimate_host and generate_host. The host/device naming convention is cleaner and mirrors the pattern used in the Notebook 06 (Asynchrony) notebooks. Made-with: Cursor

… to avoid unnecessary computation. Made-with: Cursor

…e the same input matrix for host and device. Different matrices converge at different rates, so it's only valid to benchmark on the same inputs. Use A_host for both host and device benchmarks instead of comparing A_host (CPU) against A_device (GPU-generated). Made-with: Cursor

…econds with mean ± relative stdev format. - 05 Memory Spaces: Use cupyx.profiler.benchmark with mean/stdev/runs format. - 06 Asynchrony: Use time.perf_counter for single-run timing in ms. - 40/41 Kernel Authoring: Convert benchmark output from seconds to ms. - Rename timing variable from D to T across all notebooks. Made-with: Cursor

… own cell, fix capitalization, restore eigvals timing. - Split expensive np.linalg.eigvals call into a dedicated cell timed with time.perf_counter. - Report eigvals timing alongside host/device benchmarks. - Capitalize print labels consistently (Power Iteration, Relative Error). - Use "Timing Host"/"Timing Device" instead of "Timing CPU"/"Timing GPU". Made-with: Cursor

…tions with accurate step ranges and per-step regions. Made-with: Cursor

…g from sections 3 and 4. Restore the original style from before 2f5c4fc: just call the functions, print the estimates, and show both matrices side by side. Benchmarking belongs in section 5 where cupyx.profiler.benchmark is used properly. Made-with: Cursor

…t cupy.linalg.eigvals not being implemented. Made-with: Cursor

…CPU wall-clock times for both host and device. The benchmarking cell was using .gpu_times[0] for the device benchmark but .cpu_times for the host benchmark, which is an apples-to-oranges comparison. The GPU time measures only device execution, excluding kernel launch overhead, synchronization, and other CPU-side costs. The CPU time (wall-clock) is the end-to-end time, which is the fair metric for both. This was introduced in 0c365ed. Made-with: Cursor

brycelelbach force-pushed the fix/accelerated-python-memory-space-asynchrony-and-kernel-notebooks branch from 1a8ecc0 to bc7da88 Compare March 3, 2026 20:48

brycelelbach added 18 commits March 3, 2026 17:47

Tutorials/Accelerated Python/Kernel Authoring: Improve book histogram…

7c0e231

… plot formatting, add title and dataset size display.

Tutorials/Accelerated Python/Kernel Authoring: Add configurable corre…

7c88734

…ctness check to copy kernel launch function.

Tutorials/Accelerated Python/Kernel Authoring: Display book histogram…

166df50

… dataset size in megabytes instead of bytes. Made-with: Cursor

Tutorials/Accelerated Python/Kernel Authoring: Add correctness check …

fc9cdf7

…cell before profiling copy_blocked kernel. Add a verification cell that runs the script immediately after the %%writefile cell, matching the pattern used in the book histogram notebook. Made-with: Cursor

Tutorials/Accelerated Python/Power Iteration: Fix typos in example us…

c713c1e

…age of cpyx.profiler.profile and NVTX.

Tutorials/Accelerated Python/Kernel Authoring: Apply title, TOC, sect…

2f0ff1c

…ion header, and text updates to solution notebooks. These changes were made to the exercise notebooks in 2f5c4fc but were not applied to the corresponding solution notebooks. Made-with: Cursor

Tutorials/Accelerated Python/Kernel Authoring: Add output mode to cop…

0870f94

…y kernel scripts to print problem size and dtype. Made-with: Cursor

Tutorials/Accelerated Python/Asynchrony: Limit warmup calls to 1 step…

f949362

… to avoid unnecessary computation. Made-with: Cursor

Tutorials/Accelerated Python/Asynchrony: Fix compute step NVTX annota…

e3a5d94

…tions with accurate step ranges and per-step regions. Made-with: Cursor

Tutorials/Accelerated Python/Memory Spaces: Remove outdated note abou…

b5d19ee

…t cupy.linalg.eigvals not being implemented. Made-with: Cursor

brycelelbach force-pushed the fix/accelerated-python-memory-space-asynchrony-and-kernel-notebooks branch from eab9896 to 7f7e7a4 Compare March 3, 2026 22:48

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Tutorials/Accelerated Python: Fixes and improvements to memory spaces, asynchrony, and kernel authoring notebooks#148

Tutorials/Accelerated Python: Fixes and improvements to memory spaces, asynchrony, and kernel authoring notebooks#148
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Summary

Memory Spaces (Power Iteration)

Asynchrony (Power Iteration)

Cross-Cutting (Memory Spaces + Asynchrony)

Kernel Authoring (Copy)

Kernel Authoring (Book Histogram)

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