Expectations re-order and corrected FA3 skip (#39195)

* Fix Expectations and a FA3 skip

* Fixed docstring

* Added context for Default expectation

src/transformers/testing_utils.py

@@ -3338,17 +3338,25 @@ class Expectations(UserDict[PackedDeviceProperties, Any]):
         return [(unpack_device_properties(k), v) for k, v in self.data.items()]
 
     @staticmethod
-    def is_default(properties: DeviceProperties) -> bool:
-        return all(p is None for p in properties)
+    def is_default(expectation_key: PackedDeviceProperties) -> bool:
+        """
+        This function returns True if the expectation_key is the Default expectation (None, None).
+        When an Expectation dict contains a Default value, it is generally because the test existed before Expectations.
+        When we modify a test to use Expectations for a specific hardware, we don't want to affect the tests on other
+        hardwares. Thus we set the previous value as the Default expectation with key (None, None) and add a value for
+        the specific hardware with key (hardware_type, (major, minor)).
+        """
+        return all(p is None for p in expectation_key)
 
     @staticmethod
     def score(properties: DeviceProperties, other: DeviceProperties) -> float:
         """
         Returns score indicating how similar two instances of the `Properties` tuple are.
         Rules are as follows:
-            * Matching `type` adds one point, semi-matching `type` adds half a point (e.g. cuda and rocm).
+            * Matching `type` adds one point, semi-matching `type` adds 0.1 point (e.g. cuda and rocm).
             * If types match, matching `major` adds another point, and then matching `minor` adds another.
-            * Default expectation (if present) is worth 0.1 point to distinguish it from a straight-up zero.
+            * The Default expectation (None, None) is worth 0.5 point, which is better than semi-matching. More on this
+            in the `is_default` function.
         """
         device_type, major, minor = properties
         other_device_type, other_major, other_minor = other
@@ -3361,13 +3369,13 @@ class Expectations(UserDict[PackedDeviceProperties, Any]):
                 score += 1
                 if minor is not None and minor == other_minor:
                     score += 1
-        # Semi-matching device type
+        # Semi-matching device type, which carries less importance than the default expectation
         elif device_type in ["cuda", "rocm"] and other_device_type in ["cuda", "rocm"]:
-            score = 0.5
+            score = 0.1
 
         # Default expectation
         if Expectations.is_default(other):
-            score = 0.1
+            score = 0.5
 
         return score
 

tests/test_modeling_common.py

@@ -4306,7 +4306,7 @@ class ModelTesterMixin:
     def test_flash_attn_2_from_config(self):
         self.flash_attn_from_config(attn_implementation="flash_attention_2")
 
-    @require_flash_attn
+    @require_flash_attn_3
     @require_torch_gpu
     @mark.flash_attn_3_test
     @slow