bpo-41710: gc_collect_main() uses _PyTime_GetPerfCounter() by vstinner · Pull Request #28676 · python/cpython
If the DEBUG_STATS debug flag is set, gc_collect_main() now uses
_PyTime_GetPerfCounter() instead of _PyTime_GetMonotonicClock() to
measure the elapsed time.
On Windows, _PyTime_GetMonotonicClock() only has a resolution of 15.6
ms, whereas _PyTime_GetPerfCounter() is closer to a resolution of 100
ns.