(03) dpdk: batch ownership and safety

[daniel-noland]

I know that the coverage report for this is empty.

Fixing that in a practical way requires n-vm. That is fine, it just arrives later in the stack. I may be able to pull those tests back here. Still working on that. That said, the logic itself is ready for review.

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📥 Commits

Reviewing files that changed from the base of the PR and between 8c620f5 and fecafd7.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (4)

• dpdk/Cargo.toml
• dpdk/src/mem.rs
• dpdk/src/queue/rx.rs
• dpdk/src/queue/tx.rs

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📝 Walkthrough

Walkthrough

The DPDK crate adds a fixed-capacity owning mbuf batch type. Bulk allocation, receive, and transmit APIs now use this type. Transmit returns packets that the PMD did not accept.

Changes

DPDK mbuf batches

Layer / File(s)	Summary
Mbuf batch allocation and ownership dpdk/Cargo.toml, dpdk/src/mem.rs	Pool::alloc_bulk returns MbufArray or MbufAllocError. MbufArray provides fixed-capacity storage, iteration, and bulk freeing. Mbuf::into_raw transfers ownership of a pointer.
Receive into owning batches dpdk/src/queue/rx.rs	RxQueue::receive returns an owning MbufArray and uses the shared MBUF_BURST capacity.
Transmit batches and return unsent packets dpdk/src/queue/tx.rs	TxQueue::transmit accepts an MbufArray, transfers accepted packets to the PMD, and returns the unaccepted tail.

Priority: ⬇️ Low

Merge Risk: ⚪ Minimal · up to fecaf

This change moves DPDK packet batches to an owning fixed-capacity type. It also returns packets the PMD did not accept instead of dropping them. No concrete merge-blocking risk was identified. Test coverage is acknowledged as deferred to a later PR in the stack.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 60.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 20 functions across 3 files. (1 skipped: …	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title identifies the DPDK batch ownership and safety changes described in the pull request.
Description check	✅ Passed	The description discusses coverage and testing for this change and states that the logic is ready for review.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

Docstring coverage is 60.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 20 functions across 3 files. (1 skipped: 1 unsupported.)

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 97 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
dpdk/src/mem.rs	0.00%	74 Missing ⚠️
dpdk/src/queue/tx.rs	0.00%	18 Missing ⚠️
dpdk/src/queue/rx.rs	0.00%	5 Missing ⚠️

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