make parallel loading flag a part of constants. (#12137)

src/diffusers/models/modeling_utils.py

@@ -42,9 +42,8 @@ from ..quantizers import DiffusersAutoQuantizer, DiffusersQuantizer
 from ..quantizers.quantization_config import QuantizationMethod
 from ..utils import (
     CONFIG_NAME,
-    ENV_VARS_TRUE_VALUES,
     FLAX_WEIGHTS_NAME,
-    HF_PARALLEL_LOADING_FLAG,
+    HF_ENABLE_PARALLEL_LOADING,
     SAFE_WEIGHTS_INDEX_NAME,
     SAFETENSORS_WEIGHTS_NAME,
     WEIGHTS_INDEX_NAME,
@@ -962,7 +961,7 @@ class ModelMixin(torch.nn.Module, PushToHubMixin):
         dduf_entries: Optional[Dict[str, DDUFEntry]] = kwargs.pop("dduf_entries", None)
         disable_mmap = kwargs.pop("disable_mmap", False)
 
-        is_parallel_loading_enabled = os.environ.get(HF_PARALLEL_LOADING_FLAG, "").upper() in ENV_VARS_TRUE_VALUES
+        is_parallel_loading_enabled = HF_ENABLE_PARALLEL_LOADING
         if is_parallel_loading_enabled and not low_cpu_mem_usage:
             raise NotImplementedError("Parallel loading is not supported when not using `low_cpu_mem_usage`.")
 

src/diffusers/utils/__init__.py

@@ -25,8 +25,8 @@ from .constants import (
     DIFFUSERS_DYNAMIC_MODULE_NAME,
     FLAX_WEIGHTS_NAME,
     GGUF_FILE_EXTENSION,
+    HF_ENABLE_PARALLEL_LOADING,
     HF_MODULES_CACHE,
-    HF_PARALLEL_LOADING_FLAG,
     HUGGINGFACE_CO_RESOLVE_ENDPOINT,
     MIN_PEFT_VERSION,
     ONNX_EXTERNAL_WEIGHTS_NAME,

src/diffusers/utils/constants.py

@@ -44,7 +44,7 @@ DIFFUSERS_REQUEST_TIMEOUT = 60
 DIFFUSERS_ATTN_BACKEND = os.getenv("DIFFUSERS_ATTN_BACKEND", "native")
 DIFFUSERS_ATTN_CHECKS = os.getenv("DIFFUSERS_ATTN_CHECKS", "0") in ENV_VARS_TRUE_VALUES
 DEFAULT_HF_PARALLEL_LOADING_WORKERS = 8
-HF_PARALLEL_LOADING_FLAG = "HF_ENABLE_PARALLEL_LOADING"
+HF_ENABLE_PARALLEL_LOADING = os.environ.get("HF_ENABLE_PARALLEL_LOADING", "").upper() in ENV_VARS_TRUE_VALUES
 
 # Below should be `True` if the current version of `peft` and `transformers` are compatible with
 # PEFT backend. Will automatically fall back to PEFT backend if the correct versions of the libraries are