Update appnvlm.py

appnvlm.py

@@ -13,6 +13,8 @@ def split_model():
     # Since the first GPU will be used for ViT, treat it as half a GPU.
     num_layers_per_gpu = math.ceil(num_layers / (world_size - 0.5))
     num_layers_per_gpu = [num_layers_per_gpu] * world_size
+    if not num_layers_per_gpu:
+    raise RuntimeError("No GPUs detected. NVML failed to initialize.")
     num_layers_per_gpu[0] = math.ceil(num_layers_per_gpu[0] * 0.5)
     layer_cnt = 0
     for i, num_layer in enumerate(num_layers_per_gpu):