diff --git a/i/llvm/utils/lit/lit/Test.py b/llvm/utils/lit/lit/Test.py
--- a/i/llvm/utils/lit/lit/Test.py
+++ b/llvm/utils/lit/lit/Test.py
@@ -404,4 +404,6 @@
         This can be used for test suites with long running tests to maximize
         parallelism or where it is desirable to surface their failures early.
         """
+        if '/'.join(self.path_in_suite) in self.suite.config.slowest_tests:
+            return True
         return self.suite.config.is_early
diff --git a/i/llvm/utils/lit/lit/TestingConfig.py b/llvm/utils/lit/lit/TestingConfig.py
--- a/i/llvm/utils/lit/lit/TestingConfig.py
+++ b/llvm/utils/lit/lit/TestingConfig.py
@@ -124,6 +124,8 @@
         self.limit_to_features = set(limit_to_features)
         # Whether the suite should be tested early in a given run.
         self.is_early = bool(is_early)
+        # List of slowest tests (to run early)
+        self.slowest_tests = {}
         self.parallelism_group = parallelism_group
         self._recursiveExpansionLimit = None