Simple prefetch policy (#8692)

python/sglang/srt/server_args.py

@@ -203,6 +203,7 @@ class ServerArgs:
     hicache_io_backend: str = "kernel"
     hicache_mem_layout: str = "layer_first"
     hicache_storage_backend: Optional[str] = None
+    hicache_storage_prefetch_policy: str = "best_effort"
 
     # Double Sparsity
     enable_double_sparsity: bool = False
@@ -1626,6 +1627,13 @@ class ServerArgs:
             default=ServerArgs.hicache_storage_backend,
             help="The storage backend for hierarchical KV cache.",
         )
+        parser.add_argument(
+            "--hicache-storage-prefetch-policy",
+            type=str,
+            choices=["best_effort", "wait_complete", "timeout"],
+            default=ServerArgs.hicache_storage_prefetch_policy,
+            help="Control when prefetching from the storage backend should stop.",
+        )
 
         # Double Sparsity
         parser.add_argument(