fix: 仅在可用 CUDA 时启用 xformers 内存高效注意力

app.py

@@ -363,14 +363,16 @@ class Demo:
                 model_id = "stabilityai/sdxl-turbo"
                 euler_anc = EulerAncestralDiscreteScheduler.from_pretrained(model_id, subfolder="scheduler")
                 self.pipe = StableDiffusionXLPipeline.from_pretrained(model_id, scheduler=euler_anc, torch_dtype=self.weight_dtype).to(self.device)
-                self.pipe.enable_xformers_memory_efficient_attention()
+                if torch.cuda.is_available():
+                    self.pipe.enable_xformers_memory_efficient_attention()
                 self.guidance_scale = 1
                 self.num_inference_steps = 3
                 self.current_model = 'SDXL Turbo'
             else:
                 model_id = 'stabilityai/stable-diffusion-xl-base-1.0'
                 self.pipe = StableDiffusionXLPipeline.from_pretrained(model_id, torch_dtype=self.weight_dtype).to(self.device)
-                self.pipe.enable_xformers_memory_efficient_attention()
+                if torch.cuda.is_available():
+                    self.pipe.enable_xformers_memory_efficient_attention()
                 self.guidance_scale = 7.5
                 self.num_inference_steps = 20
                 self.current_model = 'SDXL'