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| author | Victor Stinner <vstinner@python.org> | 2023-09-30 22:12:51 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-09-30 22:12:51 (GMT) |
| commit | c81521020d643b4a5183098470ef7e6470facefb (patch) | |
| tree | 9679b712dd9f4bfa003d6c8a0b188d34cf015025 /Doc | |
| parent | 2c234196ea30b9da370780204ed9068f1fb134c6 (diff) | |
| download | cpython-c81521020d643b4a5183098470ef7e6470facefb.zip cpython-c81521020d643b4a5183098470ef7e6470facefb.tar.gz cpython-c81521020d643b4a5183098470ef7e6470facefb.tar.bz2 | |
gh-109649: Add os.process_cpu_count() function (#109907)
* Refactor os_sched_getaffinity_impl(): move variable definitions to
their first assignment.
* Fix test_posix.test_sched_getaffinity(): restore the old CPU mask
when the test completes!
* Doc: Specify that os.cpu_count() counts *logicial* CPUs.
* Doc: Specify that os.sched_getaffinity(0) is related to the calling
thread.
Diffstat (limited to 'Doc')
| -rw-r--r-- | Doc/library/os.rst | 31 | ||||
| -rw-r--r-- | Doc/whatsnew/3.13.rst | 7 |
2 files changed, 31 insertions, 7 deletions
diff --git a/Doc/library/os.rst b/Doc/library/os.rst index 4ffd520..141ab0b 100644 --- a/Doc/library/os.rst +++ b/Doc/library/os.rst @@ -5141,8 +5141,12 @@ operating system. .. function:: sched_getaffinity(pid, /) - Return the set of CPUs the process with PID *pid* (or the current process - if zero) is restricted to. + Return the set of CPUs the process with PID *pid* is restricted to. + + If *pid* is zero, return the set of CPUs the calling thread of the current + process is restricted to. + + See also the :func:`process_cpu_count` function. .. _os-path: @@ -5183,12 +5187,11 @@ Miscellaneous System Information .. function:: cpu_count() - Return the number of CPUs in the system. Returns ``None`` if undetermined. - - 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))`` + Return the number of logical CPUs in the **system**. Returns ``None`` if + undetermined. + The :func:`process_cpu_count` function can be used to get the number of + logical CPUs usable by the calling thread of the **current process**. .. versionadded:: 3.4 @@ -5202,6 +5205,20 @@ Miscellaneous System Information .. availability:: Unix. +.. function:: process_cpu_count() + + Get the number of logical CPUs usable by the calling thread of the **current + process**. Returns ``None`` if undetermined. It can be less than + :func:`cpu_count` depending on the CPU affinity. + + The :func:`cpu_count` function can be used to get the number of logical CPUs + in the **system**. + + See also the :func:`sched_getaffinity` functions. + + .. versionadded:: 3.13 + + .. function:: sysconf(name, /) Return integer-valued system configuration values. If the configuration value diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst index 56618b9..484443a 100644 --- a/Doc/whatsnew/3.13.rst +++ b/Doc/whatsnew/3.13.rst @@ -163,6 +163,13 @@ opcode documented or exposed through ``dis``, and were not intended to be used externally. +os +-- + +* Add :func:`os.process_cpu_count` function to get the number of logical CPUs + usable by the calling thread of the current process. + (Contributed by Victor Stinner in :gh:`109649`.) + pathlib ------- |