[https://nvbugs/6405665][test] Disable block reuse for KV cache comparison

[jiaganc]

Summary by CodeRabbit

• Tests

  • Updated an integration test comparison to handle cache behavior more consistently during chunked prefill scenarios.
  • Adjusted test settings so both paths use the same prompt-token calculation, improving the reliability of comparison results.

• Chores

  • Removed an outdated test waiver entry.

Description

Disable block reuse for TestKVCacheV2Llama::test_chunked_prefill_multi_request and remove its NVBug 6405665 waiver.

V1 and V2 use different source-block commit policies: V1 commits only full blocks, while V2 can commit a partial source block. For this test's short prompts, V2 can therefore reuse a partial prefix that V1 cannot, causing the strict output comparison to exercise different prompt-computation paths and produce numerically different greedy output. Disabling block reuse keeps the test focused on V1-versus-V2 scheduler correctness with equivalent prompt computation.

Test Coverage

• python3 -m py_compile tests/integration/defs/kv_cache/test_kv_cache_v2_scheduler.py
• pre-commit run --files tests/integration/defs/kv_cache/test_kv_cache_v2_scheduler.py tests/integration/test_lists/waives.txt
• git diff --check
• B300 diagnosis confirmed the divergence is caused by V2 partial-prefix reuse and disappears when partial reuse is disabled. The waiver removal re-enables the target test in CI.

PR Checklist

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[jiaganc]

Wait for #15633 first.

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📥 Commits

Reviewing files that changed from the base of the PR and between 0b65e4f and d1d0a67.

📒 Files selected for processing (2)

• tests/integration/defs/kv_cache/test_kv_cache_v2_scheduler.py
• tests/integration/test_lists/waives.txt

💤 Files with no reviewable changes (1)

• tests/integration/test_lists/waives.txt

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📝 Walkthrough

Walkthrough

A test for chunked prefill multi-request scenarios was updated to disable block reuse when comparing V1 and V2 KV cache managers, ensuring consistent prompt token computation. The corresponding skip waiver for this test was removed from the waives list.

Changes

KV Cache V2 Scheduler Test Fix

Layer / File(s)	Summary
Disable block reuse and remove test waiver tests/integration/defs/kv_cache/test_kv_cache_v2_scheduler.py, tests/integration/test_lists/waives.txt	The chunked prefill multi-request test now passes kv_extra={"enable_block_reuse": False} to the V1/V2 comparison helper with added explanatory comments, and the previously associated SKIP waiver entry for this test is removed from the waives list.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Suggested reviewers: yiqingy0, Superjomn

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly matches the main change: disabling block reuse for the KV cache comparison test.
Description check	✅ Passed	The description includes the issue, solution, test coverage, and checklist, and is mostly complete.
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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[tensorrt-cicd]

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PR_Github #57487 [ run ] completed with state SUCCESS. Commit: d1d0a67
/LLM/main/L0_MergeRequest_PR pipeline #46220 completed with status: 'SUCCESS'

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