From 7ff7f5c8eb98354d3776f6c60c90aebc2b41c1da Mon Sep 17 00:00:00 2001
From: Sumanth R Hegde <39546518+SumanthRH@users.noreply.github.com>
Date: Sat, 20 Jun 2026 07:09:09 -0700
Subject: [PATCH] Revert "Fix Stale Encoder Cache After Weight Update" (#46125)

---
 vllm/entrypoints/llm.py     | 6 ------
 vllm/v1/engine/async_llm.py | 6 ------
 2 files changed, 12 deletions(-)

diff --git a/vllm/entrypoints/llm.py b/vllm/entrypoints/llm.py
index 349091f4b7..892e5035ab 100644
--- a/vllm/entrypoints/llm.py
+++ b/vllm/entrypoints/llm.py
@@ -898,12 +898,6 @@ class LLM(BeamSearchOfflineMixin, PoolingOfflineMixin, OfflineInferenceMixin):
     def finish_weight_update(self) -> None:
         """Finish the current weight update."""
         self.llm_engine.collective_rpc("finish_weight_update")
-        # Invalidate cached state computed with the old weights so it isn't
-        # reused for subsequent requests:
-        # - prefix cache: KV blocks computed with the old weights
-        # - encoder cache: multimodal embeddings keyed only by mm_hash
-        self.llm_engine.reset_prefix_cache()
-        self.llm_engine.reset_encoder_cache()
 
     def __repr__(self) -> str:
         """Return a transformers-style hierarchical view of the model."""
diff --git a/vllm/v1/engine/async_llm.py b/vllm/v1/engine/async_llm.py
index 26b3f53d2c..419e15163a 100644
--- a/vllm/v1/engine/async_llm.py
+++ b/vllm/v1/engine/async_llm.py
@@ -1109,9 +1109,3 @@ class AsyncLLM(EngineClient):
     async def finish_weight_update(self) -> None:
         """Finish the current weight update."""
         await self.collective_rpc("finish_weight_update")
-        # Invalidate cached state computed with the old weights so it isn't
-        # reused for subsequent requests:
-        # - prefix cache: KV blocks computed with the old weights
-        # - encoder cache: multimodal embeddings keyed only by mm_hash
-        await self.reset_prefix_cache()
-        await self.reset_encoder_cache()