[Backends] Provide a variant of DeviceBuffer::resize that skip data copy

[tdavidcl]

closing issue #1502

[github-actions]

Thanks @tdavidcl for opening this PR!

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[gemini-code-assist]

Summary of Changes

Hello @tdavidcl, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a significant optimization to the DeviceBuffer class by providing a mechanism to resize buffers without the overhead of data copying when the existing data is no longer relevant. This enhancement offers greater control over memory management and can lead to performance improvements in scenarios where buffer contents are frequently discarded or reinitialized after resizing, directly addressing issue #1502.

Highlights

• Enhanced DeviceBuffer::resize: The resize method in DeviceBuffer now includes an optional keep_data boolean parameter, defaulting to true, allowing callers to explicitly control whether existing data is copied during reallocation.
• New resize_discard_data method: A new convenience method, resize_discard_data(size_t new_size), has been introduced. This method calls resize with keep_data set to false, providing a clear way to resize a buffer without preserving its current contents.
• Optimized free_alloc: The free_alloc() method, which previously called resize(0), has been updated to call resize_discard_data(0). This ensures that freeing allocated memory does not involve unnecessary data copying.

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[gemini-code-assist]

Code Review

This pull request introduces a useful optimization for DeviceBuffer::resize by allowing data to be discarded when resizing. The implementation of the feature itself seems correct. However, there are a couple of points to address. The documentation for the modified resize function and the new resize_discard_data function should be improved for clarity and consistency. More importantly, this change lacks corresponding tests. It is crucial to add unit tests to verify the new behavior, especially that resize(new_size, false) correctly discards data upon reallocation.

[github-actions]

Workflow report

workflow report corresponding to commit 55598ff
Commiter email is timothee.davidcleris@proton.me
GitHub page artifact URL GitHub page artifact link (can expire)

Pre-commit check report

Pre-commit check: ✅

trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
check for merge conflicts................................................Passed
check that executables have shebangs.....................................Passed
check that scripts with shebangs are executable..........................Passed
check for added large files..............................................Passed
check for case conflicts.................................................Passed
check for broken symlinks................................................Passed
check yaml...............................................................Passed
detect private key.......................................................Passed
No-tabs checker..........................................................Passed
Tabs remover.............................................................Passed
Validate GitHub Workflows................................................Passed
clang-format.............................................................Passed
black....................................................................Passed
ruff check...............................................................Passed
Check doxygen headers....................................................Passed
Check license headers....................................................Passed
Check #pragma once.......................................................Passed
Check SYCL #include......................................................Passed
No ssh in git submodules remote..........................................Passed

Test pipeline can run.

Clang-tidy diff report

No relevant changes found.
Well done!

You should now go back to your normal life and enjoy a hopefully sunny day while waiting for the review.

Doxygen diff with main

Removed warnings : 0
New warnings : 0
Warnings count : 7609 → 7609 (0.0%)

Detailed changes :