[achirkin]

Switch to the new raft::launch_kernel API in a few places across cuVS as a preview before the full refactoring.

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[achirkin]

/ok to test

[achirkin]

/ok to test

[achirkin]

/ok to test

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

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📥 Commits

Reviewing files that changed from the base of the PR and between 24b0b17 and b9187cc.

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📒 Files selected for processing (3)

• cpp/src/neighbors/detail/cagra/search_multi_cta_kernel_launcher_jit.cuh
• cpp/src/neighbors/detail/cagra/search_multi_kernel_launcher_jit.cuh
• cpp/src/neighbors/detail/cagra/search_single_cta_kernel_launcher_jit.cuh

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📝 Summary

Summary by CodeRabbit

• Refactor
  • Updated GPU processing for CAGRA search operations to use a consistent launch approach. Existing search inputs and shared-memory behavior are retained, with no changes to the available search features.

Walkthrough

The CAGRA JIT launch paths now use raft::launch_kernel with typed kernel references instead of algorithm launcher dispatch calls. The changes also remove post-launch cudaPeekAtLastError() checks and pass sampling counts directly.

Changes

CAGRA JIT launches

Layer / File(s)	Summary
Multi-CTA search launches cpp/src/neighbors/detail/cagra/search_multi_cta_kernel_launcher_jit.cuh	The multi-CTA search paths use raft::launch_kernel with typed kernel references. They pass sampling counts directly and remove post-launch error checks.
Multi-kernel helper launches cpp/src/neighbors/detail/cagra/search_multi_kernel_launcher_jit.cuh	Random pickup, child-node distance, and filtering use raft::launch_kernel. The launches retain their applicable shared-memory settings, and the post-launch error checks are removed.
Single-CTA search launches cpp/src/neighbors/detail/cagra/search_single_cta_kernel_launcher_jit.cuh	Persistent, single-query, and multi-partition paths use raft::launch_kernel. Cooperative launch and shared-memory sizing are retained where applicable. Sampling counts are passed directly.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Refactor

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Merge Risk: ⚪ Minimal · up to b9187

The launch changes have no identified issue requiring a fix before merge.

Pre-merge checks | 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description check		The description directly states that the changes switch cuVS code to the new raft::launch_kernel API, which matches the changeset.
Title check		The title clearly and concisely identifies the main change: using raft::launch_kernel in CAGRA search JIT kernels.
Docstring Coverage		No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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[divyegala]

/merge