[RL][Feature] R3 Phase 2: routing data follows KVCache block lifecycl…

[gongshaotian]

…e (swap/storage/PD)

Implement Phase 2 of RoutingReplay (R3) to make routing data compatible with CPUPrefixCache swap, KVCacheStorage persistence, and PD disaggregation.

Key changes:

• Replace large GPU routing_replay_table (~3.8GB) with small transient buffer (~3.8MB)
• Add SharedMemory-based routing_host_buffer/routing_swap_buffer for cross-process access
• Routing data now follows KVCache blocks through GPU<->CPU swap (CTM numpy memcpy)
• Routing data persists/restores with KVCacheStorage (mooncake/file backends)
• PD disaggregation: P gathers prefill routing via ZMQ, D writes to routing_host_buffer
• Move routing aggregation from Worker to Engine/TokenProcessor layer
• AuxBlockDataSpec abstraction for extensible block-bound auxiliary data

Files: cache_data, cache_transfer_manager, prefix_cache_manager, common_engine, request, resource_manager_v1, forward_meta, moe, routing_indices_cache, pre_and_post_process, token_processor, gpu_model_runner

Motivation

💡 If this PR is a Cherry Pick, the PR title needs to follow the format by adding the [Cherry-Pick] label at the very beginning and appending the original PR ID at the end. For example, [Cherry-Pick][CI] Add check trigger and logic(#5191)

💡 如若此PR是Cherry Pick，PR标题需遵循格式，在最开始加上[Cherry-Pick]标签，以及最后面加上原PR ID，例如[Cherry-Pick][CI] Add check trigger and logic(#5191)

Modifications

Usage or Command

Accuracy Tests

Checklist

• Add at least a tag in the PR title.
  • Tag list: [[FDConfig],[APIServer],[Engine], [Scheduler], [PD Disaggregation], [Executor], [Graph Optimization], [Speculative Decoding], [RL], [Models], [Quantization], [Loader], [OP], [KVCache], [DataProcessor], [BugFix], [Docs], [CI], [Optimization], [Feature], [Benchmark], [Others], [XPU], [HPU], [GCU], [DCU], [Iluvatar], [Metax]]
  • You can add new tags based on the PR content, but the semantics must be clear.
• Format your code, run pre-commit before commit.
• Add unit tests. Please write the reason in this PR if no unit tests.
• Provide accuracy results.
• If the current PR is submitting to the release branch, make sure the PR has been submitted to the develop branch, then cherry-pick it to the release branch with the [Cherry-Pick] PR tag.

[paddle-bot]

Thanks for your contribution!

[codecov-commenter]

Codecov Report

❌ Patch coverage is 20.51282% with 310 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (release/2.5@2efab46). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
fastdeploy/cache_manager/cache_transfer_manager.py	8.84%	102 Missing and 1 partial ⚠️
...model_executor/layers/moe/routing_indices_cache.py	18.69%	100 Missing ⚠️
fastdeploy/output/token_processor.py	6.77%	54 Missing and 1 partial ⚠️
fastdeploy/engine/common_engine.py	5.55%	16 Missing and 1 partial ⚠️
fastdeploy/model_executor/pre_and_post_process.py	0.00%	16 Missing ⚠️
fastdeploy/cache_manager/prefix_cache_manager.py	18.18%	8 Missing and 1 partial ⚠️
fastdeploy/model_executor/layers/moe/moe.py	0.00%	4 Missing ⚠️
fastdeploy/engine/engine.py	0.00%	1 Missing and 1 partial ⚠️
fastdeploy/engine/request.py	77.77%	1 Missing and 1 partial ⚠️
fastdeploy/cache_manager/cache_data.py	93.33%	1 Missing ⚠️
... and 1 more

Additional details and impacted files

@@              Coverage Diff               @@
##             release/2.5    #7099   +/-   ##
==============================================
  Coverage               ?   68.69%           
==============================================
  Files                  ?      390           
  Lines                  ?    54465           
  Branches               ?     8565           
==============================================
  Hits                   ?    37413           
  Misses                 ?    14345           
  Partials               ?     2707           

Flag	Coverage Δ
GPU	68.69% <20.51%> (?)

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