Fix a bug in schedule_policy (#6276)

python/sglang/srt/managers/schedule_policy.py

@@ -468,6 +468,9 @@ class PrefillAdder:
             return AddReqResult.OTHER
 
         with self._lock_node(req.last_node):
+            if total_tokens > self.rem_total_tokens:
+                return AddReqResult.NO_TOKEN
+
             if (
                 enable_hierarchical_cache
                 and req.last_node_global is not None