.. cmdoption:: -j N
Use *N* workers to compile the files within the given directory.
- If ``0`` is used, then the result of :func:`os.cpu_count()`
+ If ``0`` is used, then the result of :func:`os.process_cpu_count()`
will be used.
.. cmdoption:: --invalidation-mode [timestamp|checked-hash|unchecked-hash]
ThreadPoolExecutor now reuses idle worker threads before starting
*max_workers* worker threads too.
+ .. versionchanged:: 3.13
+ Default value of *max_workers* is changed to
+ ``min(32, (os.process_cpu_count() or 1) + 4)``.
+
.. _threadpoolexecutor-example:
An :class:`Executor` subclass that executes calls asynchronously using a pool
of at most *max_workers* processes. If *max_workers* is ``None`` or not
- given, it will default to the number of processors on the machine.
+ given, it will default to :func:`os.process_cpu_count`.
If *max_workers* is less than or equal to ``0``, then a :exc:`ValueError`
will be raised.
On Windows, *max_workers* must be less than or equal to ``61``. If it is not
different start method. See the :func:`os.fork` documentation for
further explanation.
+ .. versionchanged:: 3.13
+ *max_workers* uses :func:`os.process_cpu_count` by default, instead of
+ :func:`os.cpu_count`.
+
.. _processpoolexecutor-example:
ProcessPoolExecutor Example
This number is not equivalent to the number of CPUs the current process can
use. The number of usable CPUs can be obtained with
- ``len(os.sched_getaffinity(0))``
+ :func:`os.process_cpu_count`.
When the number of CPUs cannot be determined a :exc:`NotImplementedError`
is raised.
.. seealso::
- :func:`os.cpu_count`
+ :func:`os.cpu_count` and :func:`os.process_cpu_count`
.. function:: current_process()
callbacks and has a parallel map implementation.
*processes* is the number of worker processes to use. If *processes* is
- ``None`` then the number returned by :func:`os.cpu_count` is used.
+ ``None`` then the number returned by :func:`os.process_cpu_count` is used.
If *initializer* is not ``None`` then each worker process will call
``initializer(*initargs)`` when it starts.
.. versionadded:: 3.4
*context*
+ .. versionchanged:: 3.13
+ *processes* uses :func:`os.process_cpu_count` by default, instead of
+ :func:`os.cpu_count`.
+
.. note::
Worker processes within a :class:`Pool` typically live for the complete
:meth:`~multiprocessing.pool.Pool.terminate` manually.
*processes* is the number of worker threads to use. If *processes* is
- ``None`` then the number returned by :func:`os.cpu_count` is used.
+ ``None`` then the number returned by :func:`os.process_cpu_count` is used.
If *initializer* is not ``None`` then each worker process will call
``initializer(*initargs)`` when it starts.
of the ``optimize`` argument.
(Contributed by Irit Katriel in :gh:`108113`).
+* :mod:`multiprocessing`, :mod:`concurrent.futures`, :mod:`compileall`:
+ Replace :func:`os.cpu_count` with :func:`os.process_cpu_count` to select the
+ default number of worker threads and processes. Get the CPU affinity
+ if supported.
+ (Contributed by Victor Stinner in :gh:`109649`.)
+
+
New Modules
===========
_check_system_limits()
if max_workers is None:
- self._max_workers = os.cpu_count() or 1
+ self._max_workers = os.process_cpu_count() or 1
if sys.platform == 'win32':
self._max_workers = min(_MAX_WINDOWS_WORKERS,
self._max_workers)
# * CPU bound task which releases GIL
# * I/O bound task (which releases GIL, of course)
#
- # We use cpu_count + 4 for both types of tasks.
+ # We use process_cpu_count + 4 for both types of tasks.
# But we limit it to 32 to avoid consuming surprisingly large resource
# on many core machine.
- max_workers = min(32, (os.cpu_count() or 1) + 4)
+ max_workers = min(32, (os.process_cpu_count() or 1) + 4)
if max_workers <= 0:
raise ValueError("max_workers must be greater than 0")
self._initargs = initargs
if processes is None:
- processes = os.cpu_count() or 1
+ processes = os.process_cpu_count() or 1
if processes < 1:
raise ValueError("Number of processes must be at least 1")
if maxtasksperchild is not None:
if self.num_workers < 0:
# Use all CPUs + 2 extra worker processes for tests
# that like to sleep
- self.num_workers = (os.cpu_count() or 1) + 2
+ self.num_workers = (os.process_cpu_count() or 1) + 2
# For a partial run, we do not need to clutter the output.
if (self.want_header
cpu_count = os.cpu_count()
if cpu_count:
+ process_cpu_count = os.process_cpu_count()
+ if process_cpu_count and process_cpu_count != cpu_count:
+ cpu_count = f"{process_cpu_count} (process) / {cpu_count} (system)"
print("== CPU count:", cpu_count)
print("== encodings: locale=%s, FS=%s"
% (locale.getencoding(), sys.getfilesystemencoding()))
'getresgid',
'getresuid',
'getuid',
+ 'process_cpu_count',
'uname',
):
call_func(info_add, 'os.%s' % func, os, func)
def test_default_workers(self):
executor = self.executor_type()
- expected = min(32, (os.cpu_count() or 1) + 4)
+ expected = min(32, (os.process_cpu_count() or 1) + 4)
self.assertEqual(executor._max_workers, expected)
def test_saturation(self):
--- /dev/null
+:mod:`multiprocessing`, :mod:`concurrent.futures`, :mod:`compileall`:
+Replace :func:`os.cpu_count` with :func:`os.process_cpu_count` to select the
+default number of worker threads and processes. Get the CPU affinity if
+supported. Patch by Victor Stinner.
out, _ = p.communicate()
write_output(out, p.returncode)
- N = os.cpu_count()
+ N = os.process_cpu_count()
t = N * [None]
for i in range(N):
if not MAKE:
raise UnsupportedError('make')
- cores = os.cpu_count()
+ cores = os.process_cpu_count()
if cores and cores >= 3:
# this test is most often run as part of the whole suite with a lot
# of other tests running in parallel, from 1-2 vCPU systems up to
build_template = None
depend_target = None
install_target = 'install'
- jobs = os.cpu_count()
+ if hasattr(os, 'process_cpu_count'):
+ jobs = os.process_cpu_count()
+ else:
+ jobs = os.cpu_count()
module_files = (
os.path.join(PYTHONROOT, "Modules/_ssl.c"),
def getenv(self) -> Dict[str, Any]:
"""Generate environ dict for platform"""
env = os.environ.copy()
- env.setdefault("MAKEFLAGS", f"-j{os.cpu_count()}")
+ if hasattr(os, 'process_cpu_count'):
+ cpu_count = os.process_cpu_count()
+ else:
+ cpu_count = os.cpu_count()
+ env.setdefault("MAKEFLAGS", f"-j{cpu_count}")
platenv = self.host.platform.getenv(self)
for key, value in platenv.items():
if value is None:
projects / thirdparty / Python / cpython.git / commitdiff
