Fix a distributed initialization error (#13843)

Signed-off-by: Zhiyu Cheng <zhiyuc@nvidia.com>

python/sglang/srt/model_loader/loader.py

@@ -61,6 +61,7 @@ from sglang.srt.connector.utils import parse_model_name
 from sglang.srt.distributed import (
     get_tensor_model_parallel_rank,
     get_tensor_model_parallel_world_size,
+    model_parallel_is_initialized,
 )
 from sglang.srt.layers.modelopt_utils import QUANT_CFG_CHOICES
 from sglang.srt.layers.quantization.base_config import QuantizationConfig
@@ -1863,7 +1864,10 @@ class ModelOptModelLoader(DefaultModelLoader):
             # Apply quantization
             mtq.quantize(model, quant_cfg, forward_loop=calibrate_loop)
 
-            if get_tensor_model_parallel_rank() == 0:
+            if (
+                not model_parallel_is_initialized()
+                or get_tensor_model_parallel_rank() == 0
+            ):
                 mtq.print_quant_summary(model)
 
             # Save checkpoint if path provided

python/sglang/srt/utils/common.py

@@ -1171,9 +1171,12 @@ def set_ulimit(target_soft_limit=65535):
 
 
 def rank0_log(msg: str):
-    from sglang.srt.distributed import get_tensor_model_parallel_rank
+    from sglang.srt.distributed import (
+        get_tensor_model_parallel_rank,
+        model_parallel_is_initialized,
+    )
 
-    if get_tensor_model_parallel_rank() == 0:
+    if not model_parallel_is_initialized() or get_tensor_model_parallel_rank() == 0:
         logger.info(msg)