diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
@@ -14,7 +14,7 @@
from test.libregrtest.runtest import (
    findtests, runtest, get_abs_module,
    STDTESTS, NOTTESTS, PASSED, FAILED, ENV_CHANGED, SKIPPED, RESOURCE_DENIED,
-    INTERRUPTED, CHILD_ERROR, TEST_DID_NOT_RUN,
    PROGRESS_MIN_TIME, format_test_result, is_failed)
from test.libregrtest.setup import setup_tests
from test.libregrtest.utils import removepy, count, format_duration, printlist
@@ -114,6 +114,8 @@ def accumulate_result(self, result, rerun=False):
            self.run_no_tests.append(test_name)
        elif ok == INTERRUPTED:
            self.interrupted = True
        else:
            raise ValueError("invalid test result: %r" % ok)


diff --git a/Lib/test/libregrtest/runtest.py b/Lib/test/libregrtest/runtest.py
@@ -13,7 +13,7 @@
from test import support
from test.libregrtest.refleak import dash_R, clear_caches
from test.libregrtest.save_env import saved_test_environment
-from test.libregrtest.utils import print_warning


# Test result constants.
@@ -25,6 +25,7 @@
INTERRUPTED = -4
CHILD_ERROR = -5   # error in a child process
TEST_DID_NOT_RUN = -6

_FORMAT_TEST_RESULT = {
    PASSED: '%s passed',
@@ -35,6 +36,7 @@
    INTERRUPTED: '%s interrupted',
    CHILD_ERROR: '%s crashed',
    TEST_DID_NOT_RUN: '%s run no tests',
}

# Minimum duration of a test to display its duration or to mention that
@@ -75,7 +77,10 @@ def is_failed(result, ns):

def format_test_result(result):
    fmt = _FORMAT_TEST_RESULT.get(result.result, "%s")
-    return fmt % result.test_name


def findtestdir(path=None):
@@ -179,6 +184,7 @@ def runtest(ns, test_name):
        FAILED           test failed
        PASSED           test passed
        EMPTY_TEST_SUITE test ran no subtests.

    If ns.xmlpath is not None, xml_data is a list containing each
    generated testsuite element.

diff --git a/Lib/test/libregrtest/runtest_mp.py b/Lib/test/libregrtest/runtest_mp.py
@@ -13,7 +13,7 @@

from test.libregrtest.runtest import (
    runtest, INTERRUPTED, CHILD_ERROR, PROGRESS_MIN_TIME,
-    format_test_result, TestResult, is_failed)
from test.libregrtest.setup import setup_tests
from test.libregrtest.utils import format_duration

@@ -103,11 +103,12 @@ class ExitThread(Exception):


class MultiprocessThread(threading.Thread):
-    def __init__(self, pending, output, ns):
        super().__init__()
        self.pending = pending
        self.output = output
        self.ns = ns
        self.current_test_name = None
        self.start_time = None
        self._popen = None
@@ -126,6 +127,12 @@ def __repr__(self):
        return '<%s>' % ' '.join(info)

    def kill(self):
        self._killed = True

        popen = self._popen
@@ -136,6 +143,13 @@ def kill(self):
        # does not hang
        popen.stdout.close()
        popen.stderr.close()

    def _runtest(self, test_name):
        try:
@@ -154,7 +168,19 @@ def _runtest(self, test_name):
                        raise ExitThread

                    try:
                        stdout, stderr = popen.communicate()
                    except OSError:
                        if self._killed:
                            # kill() has been called: communicate() fails
@@ -163,7 +189,6 @@ def _runtest(self, test_name):
                        raise
                except:
                    self.kill()
-                    popen.wait()
                    raise

            retcode = popen.wait()
@@ -191,8 +216,7 @@ def _runtest(self, test_name):
                    err_msg = "Failed to parse worker JSON: %s" % exc

        if err_msg is not None:
-            test_time = time.monotonic() - self.start_time
-            result = TestResult(test_name, CHILD_ERROR, test_time, None)

        return MultiprocessResult(result, stdout, stderr, err_msg)

@@ -236,13 +260,16 @@ def __init__(self, regrtest):
        self.output = queue.Queue()
        self.pending = MultiprocessIterator(self.regrtest.tests)
        if self.ns.timeout is not None:
-            self.test_timeout = self.ns.timeout * 1.5
        else:
-            self.test_timeout = None
        self.workers = None

    def start_workers(self):
-        self.workers = [MultiprocessThread(self.pending, self.output, self.ns)
                        for _ in range(self.ns.use_mp)]
        print("Run tests in parallel using %s child processes"
              % len(self.workers))
@@ -274,8 +301,8 @@ def _get_result(self):
                return None

        while True:
-            if self.test_timeout is not None:
-                faulthandler.dump_traceback_later(self.test_timeout, exit=True)

            # wait for a thread
            timeout = max(PROGRESS_UPDATE, PROGRESS_MIN_TIME)
@@ -343,7 +370,7 @@ def run_tests(self):
            print()
            self.regrtest.interrupted = True
        finally:
-            if self.test_timeout is not None:
                faulthandler.cancel_dump_traceback_later()

        # a test failed (and --failfast is set) or all tests completed

diff --git a/Lib/test/libregrtest/win_utils.py b/Lib/test/libregrtest/win_utils.py
@@ -18,13 +18,14 @@
class WindowsLoadTracker():
    """
    This class asynchronously interacts with the `typeperf` command to read
-    the system load on Windows. Mulitprocessing and threads can't be used
    here because they interfere with the test suite's cases for those
    modules.
    """

    def __init__(self):
        self.load = 0.0
        self.start()

    def start(self):

diff --git a/Lib/test/test_regrtest.py b/Lib/test/test_regrtest.py
@@ -1121,6 +1121,33 @@ def test_garbage(self):
                                  env_changed=[testname],
                                  fail_env_changed=True)

    def test_cleanup(self):
        dirname = os.path.join(self.tmptestdir, "test_python_123")
        os.mkdir(dirname)