[Python-checkins] bpo-33166: Change os.cpu_count to return active (real) processors (GH-15949)
Zachary Ware
webhook-mailer at python.org
Wed Sep 11 11:15:43 EDT 2019
https://github.com/python/cpython/commit/aa929273caca2f4e24e3aa9e790272fd4458ad35
commit: aa929273caca2f4e24e3aa9e790272fd4458ad35
branch: master
author: Steve Dower <steve.dower at python.org>
committer: Zachary Ware <zachary.ware at gmail.com>
date: 2019-09-11T16:15:39+01:00
summary:
bpo-33166: Change os.cpu_count to return active (real) processors (GH-15949)
files:
A Misc/NEWS.d/next/Windows/2019-09-11-14-42-04.bpo-36634.8Un8ih.rst
M Modules/posixmodule.c
diff --git a/Misc/NEWS.d/next/Windows/2019-09-11-14-42-04.bpo-36634.8Un8ih.rst b/Misc/NEWS.d/next/Windows/2019-09-11-14-42-04.bpo-36634.8Un8ih.rst
new file mode 100644
index 000000000000..1affdd81cbfa
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2019-09-11-14-42-04.bpo-36634.8Un8ih.rst
@@ -0,0 +1,2 @@
+:func:`os.cpu_count` now returns active processors rather than maximum
+processors.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 88d3d8323950..089572f4fdab 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -12204,23 +12204,9 @@ os_cpu_count_impl(PyObject *module)
{
int ncpu = 0;
#ifdef MS_WINDOWS
- /* Vista is supported and the GetMaximumProcessorCount API is Win7+
- Need to fallback to Vista behavior if this call isn't present */
- HINSTANCE hKernel32;
- static DWORD(CALLBACK *_GetMaximumProcessorCount)(WORD) = NULL;
- Py_BEGIN_ALLOW_THREADS
- hKernel32 = GetModuleHandleW(L"KERNEL32");
- *(FARPROC*)&_GetMaximumProcessorCount = GetProcAddress(hKernel32,
- "GetMaximumProcessorCount");
- Py_END_ALLOW_THREADS
- if (_GetMaximumProcessorCount != NULL) {
- ncpu = _GetMaximumProcessorCount(ALL_PROCESSOR_GROUPS);
- }
- else {
- SYSTEM_INFO sysinfo;
- GetSystemInfo(&sysinfo);
- ncpu = sysinfo.dwNumberOfProcessors;
- }
+ /* Declare prototype here to avoid pulling in all of the Win7 APIs in 3.8 */
+ DWORD WINAPI GetActiveProcessorCount(WORD group);
+ ncpu = GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
#elif defined(__hpux)
ncpu = mpctl(MPC_GETNUMSPUS, NULL, NULL);
#elif defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_ONLN)
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