Avoid hangs on many-core Windows machines

doc/whatsnew/2/2.15/index.rst

@@ -94,3 +94,6 @@ Internal changes
   let the functional test fail with a default value.
 
   Refs #6891
+
+* Fixed an issue where many-core Windows machines (>~60 logical processors) would hang when
+  using the default jobs count.

pylint/lint/base_options.py

@@ -244,7 +244,8 @@ def _make_linter_options(linter: PyLinter) -> Options:
                 "short": "j",
                 "default": 1,
                 "help": "Use multiple processes to speed up Pylint. Specifying 0 will "
-                "auto-detect the number of processors available to use.",
+                "auto-detect the number of processors available to use, and will cap "
+                "the count on Windows to avoid hangs.",
             },
         ),
         (

pylint/lint/run.py

@@ -82,6 +82,11 @@ def _cpu_count() -> int:
         cpu_count = multiprocessing.cpu_count()
     else:
         cpu_count = 1
+    if sys.platform == "win32":
+        # Using too many child processes in Python 3 hits either hangs or a
+        # ValueError exception, and, has diminishing returns. Clamp to 56 to
+        # give margin for error.
+        cpu_count = min(cpu_count, 56)
     if cpu_share is not None:
         return min(cpu_share, cpu_count)
     return cpu_count