diff options
| -rw-r--r-- | Misc/NEWS.d/next/Windows/2017-08-04-10-05-19.bpo-30581.OQhR7l.rst | 2 | ||||
| -rw-r--r-- | Modules/posixmodule.c | 19 |
2 files changed, 18 insertions, 3 deletions
diff --git a/Misc/NEWS.d/next/Windows/2017-08-04-10-05-19.bpo-30581.OQhR7l.rst b/Misc/NEWS.d/next/Windows/2017-08-04-10-05-19.bpo-30581.OQhR7l.rst new file mode 100644 index 0000000..6591fa0 --- /dev/null +++ b/Misc/NEWS.d/next/Windows/2017-08-04-10-05-19.bpo-30581.OQhR7l.rst @@ -0,0 +1,2 @@ +os.cpu_count() now returns the correct number of processors on Windows +when the number of logical processors is greater than 64. diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c index 111e4c9..ead2ea9 100644 --- a/Modules/posixmodule.c +++ b/Modules/posixmodule.c @@ -11028,9 +11028,22 @@ os_cpu_count_impl(PyObject *module) { int ncpu = 0; #ifdef MS_WINDOWS - SYSTEM_INFO sysinfo; - GetSystemInfo(&sysinfo); - ncpu = sysinfo.dwNumberOfProcessors; + /* Vista is supported and the GetMaximumProcessorCount API is Win7+ + Need to fallback to Vista behavior if this call isn't present */ + HINSTANCE hKernel32; + hKernel32 = GetModuleHandleW(L"KERNEL32"); + + static DWORD(CALLBACK *_GetMaximumProcessorCount)(WORD) = NULL; + *(FARPROC*)&_GetMaximumProcessorCount = GetProcAddress(hKernel32, + "GetMaximumProcessorCount"); + if (_GetMaximumProcessorCount != NULL) { + ncpu = _GetMaximumProcessorCount(ALL_PROCESSOR_GROUPS); + } + else { + SYSTEM_INFO sysinfo; + GetSystemInfo(&sysinfo); + ncpu = sysinfo.dwNumberOfProcessors; + } #elif defined(__hpux) ncpu = mpctl(MPC_GETNUMSPUS, NULL, NULL); #elif defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_ONLN) |