[BugFix] Fix async scheduling + chunked prefill + preemption #28787
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Signed-off-by: Nick Hill <[email protected]>
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This pull request addresses a bug related to async scheduling, chunked prefill, and preemption. The core of the fix is in vllm/v1/core/sched/scheduler.py, where previously only a slice of token IDs was being sent for requests undergoing chunked prefill. This was incorrect as the connector requires the full list of tokens for prefix matching. The change correctly sends a full copy of the token IDs. To facilitate this, a copy() method was added to the ConstantList class. The re-enabling of previously skipped tests in tests/v1/e2e/test_async_scheduling.py validates the fix. The changes are correct, well-targeted, and I have no further recommendations.
DarkLight1337
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Nov 16, 2025
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…oject#28787) Signed-off-by: Nick Hill <[email protected]> Signed-off-by: Bram Wasti <[email protected]>
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Nov 26, 2025
…oject#28787) Signed-off-by: Nick Hill <[email protected]>
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…oject#28787) Signed-off-by: Nick Hill <[email protected]>
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…oject#28787) Signed-off-by: Nick Hill <[email protected]>
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…oject#28787) Signed-off-by: Nick Hill <[email protected]> Signed-off-by: Xingyu Liu <[email protected]>
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Small fix, took a while to track down 😅
The populated
all_token_idsshould never have been truncated since they are used to recover output ids following preemption in the async scheduling case.