Don't enable pytorch attention on AMD if triton isn't available. (#9747)

Author: comfyanonymous

comfy/model_management.py

@@ -22,6 +22,7 @@
 from comfy.cli_args import args, PerformanceFeature
 import torch
 import sys
+import importlib
 import platform
 import weakref
 import gc
@@ -336,12 +337,13 @@ def amd_min_version(device=None, min_rdna_version=0):
         logging.info("AMD arch: {}".format(arch))
         logging.info("ROCm version: {}".format(rocm_version))
         if args.use_split_cross_attention == False and args.use_quad_cross_attention == False:
-            if torch_version_numeric >= (2, 7):  # works on 2.6 but doesn't actually seem to improve much
-                if any((a in arch) for a in ["gfx90a", "gfx942", "gfx1100", "gfx1101", "gfx1151"]):  # TODO: more arches, TODO: gfx950
-                    ENABLE_PYTORCH_ATTENTION = True
-#            if torch_version_numeric >= (2, 8):
-#                if any((a in arch) for a in ["gfx1201"]):
-#                    ENABLE_PYTORCH_ATTENTION = True
+            if importlib.util.find_spec('triton') is not None:  # AMD efficient attention implementation depends on triton. TODO: better way of detecting if it's compiled in or not.
+                if torch_version_numeric >= (2, 7):  # works on 2.6 but doesn't actually seem to improve much
+                    if any((a in arch) for a in ["gfx90a", "gfx942", "gfx1100", "gfx1101", "gfx1151"]):  # TODO: more arches, TODO: gfx950
+                        ENABLE_PYTORCH_ATTENTION = True
+#                if torch_version_numeric >= (2, 8):
+#                    if any((a in arch) for a in ["gfx1201"]):
+#                        ENABLE_PYTORCH_ATTENTION = True
         if torch_version_numeric >= (2, 7) and rocm_version >= (6, 4):
             if any((a in arch) for a in ["gfx1201", "gfx942", "gfx950"]):  # TODO: more arches
                 SUPPORT_FP8_OPS = True