Specify that os.cpu_count() counts *logicial* CPUs

Author: vstinner

Doc/library/os.rst

@@ -5155,10 +5155,11 @@ Miscellaneous System Information
 
 .. function:: cpu_count(*, usable=False)
 
-   Return the number of CPUs in the system. Returns ``None`` if undetermined.
+   Return the number of logical CPUs in the system. Returns ``None`` if
+   undetermined.
 
-   If *usable* is true, return the number of CPUs the current process can use.
-   If the :func:`sched_getaffinity` function is available, return
+   If *usable* is true, return the number of logical CPUs the current process
+   can use.  If the :func:`sched_getaffinity` function is available, return
    ``len(os.sched_getaffinity(0))``, otherwise just return
    ``cpu_count(usable=False)``.