From ff1f68252c2b5b343aa6ef2aa14e6d4753ae4871 Mon Sep 17 00:00:00 2001
From: Faradawn Yang <73060648+faradawn@users.noreply.github.com>
Date: Mon, 11 Aug 2025 14:20:39 -0700
Subject: [PATCH] =?UTF-8?q?[fix]=20Set=20Radix=20tree=20root=20node=20hash?=
 =?UTF-8?q?=C2=A0to=20None=20=20-=20Nvidia=20Dynamo=20Integration=20(#9030?=
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Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
---
 python/sglang/srt/mem_cache/radix_cache.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/python/sglang/srt/mem_cache/radix_cache.py b/python/sglang/srt/mem_cache/radix_cache.py
index 21fe3b2b9..847a7dbbf 100644
--- a/python/sglang/srt/mem_cache/radix_cache.py
+++ b/python/sglang/srt/mem_cache/radix_cache.py
@@ -495,7 +495,7 @@ class RadixCache(BasePrefixCache):
         # One BlockStored per ``page_size`` chunk.
         if self.enable_kv_cache_events:
             # First chunk links to the last page of the parent node (if any).
-            if node.parent is None:
+            if node.parent is None or node != self.root_node:
                 parent_block_hash = None
             else:
                 last_page_start = (