Hi Tony, On 11/30/2023 4:37 PM, Tony Luck wrote: > On Thu, Nov 30, 2023 at 03:40:52PM -0800, Reinette Chatre wrote: >> Hi Tony, >> >> On 11/30/2023 2:43 PM, Tony Luck wrote: >>> On Thu, Nov 30, 2023 at 01:47:10PM -0800, Reinette Chatre wrote: >> for something that does not change while not holding the hotplug lock. Reading its >> description more closely also makes me wonder if the later >> num_online_cpus() != num_present_cpus() >> should also maybe be >> num_online_cpus() != num_possible_cpus() ? >> It seems to more closely match the intention. > > This seems problematic. On a system that does support physical CPU > hotplug num_possible_cpus() may be some very large number. Reserving > space for CPUs that can be added later. None of those CPUs can be online > (obviously!). So this test would fail on such a system. Thank you for clarifying. It was not obvious to me how these bitmaps are different with physical hotplug. Reinette
