[Tracking issue] [Help wanted]: Deprecate BlockManagerV1

[cadedaniel]

Anything you want to discuss about vllm.

We recently refactored the block allocation and management subsystem to improve its testability (PR https://github.com/vllm-project/vllm/pull/3492). We can replace the old implementation once the V2 is feature-complete and performant. This is a tracking issue for the remaining work.

Missing items:

• Prefix caching https://github.com/vllm-project/vllm/issues/3667
• CPU swapping https://github.com/vllm-project/vllm/issues/3666
• Sliding window support https://github.com/vllm-project/vllm/issues/3665
• Profile and optimize block manager V2 https://github.com/vllm-project/vllm/issues/4536