fix: lock shared region before clearing proc slots in oom_check

[mesutoezdil]

oom_check called clear_proc_slot_nolock without holding the shrreg lock, unlike its other caller. Concurrent OOM across processes can race on the shared proc table. Now it locks around the call, same as init_proc_slot_withlock.

Summary by CodeRabbit

• Bug Fixes

  • Improved out-of-memory handling during resource allocation to safely retry after clearing an available process slot.

• Documentation

  • Clarified internal comments related to GPU allocation and resource tracking.

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[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: mesutoezdil
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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 14eed1f2-dbd8-4480-a191-e0c87de4156a

📥 Commits

Reviewing files that changed from the base of the PR and between 06e6980 and 57f548d.

📒 Files selected for processing (1)

• src/allocator/allocator.c

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📝 Walkthrough

Walkthrough

The allocator now protects OOM process-slot cleanup with shared-region locking, stores the cleanup result before retrying, and updates two nearby add_chunk comments.

Changes

Allocator OOM synchronization

Layer / File(s)	Summary
Protect OOM cleanup with shared-region locking src/allocator/allocator.c	oom_check wraps process-slot clearing with lock_shrreg() and unlock_shrreg(), uses the result for retry logic, and revises two add_chunk comments.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: archlitchi, chaunceyjiang

Poem

I’m a rabbit guarding slots in the night,
Locking shared regions snug and tight.
OOM hops back for one more try,
While comments wave as chunks pass by.
Carrots cheer the safer flight!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: locking the shared region before clearing proc slots in oom_check.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.

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• Create PR with unit tests

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[mesutoezdil]

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