On Fri, Jul 03, 2020 at 06:56:27PM +0200, Peter Zijlstra wrote: > On Fri, Jul 03, 2020 at 05:57:49PM +0200, Uladzislau Rezki wrote: > > Hello, folk. > > > > I have a system based on AMD 3970x CPUs. It has 32 physical cores > > and 64 threads. It seems that "nr_cpu_ids" variable is not correctly > > set on latest 5.8-rc3 kernel. Please have a look below on dmesg output: > > > > <snip> > > urezki@pc638:~$ sudo dmesg | grep 128 > > [ 0.000000] IOAPIC[0]: apic_id 128, version 33, address 0xfec00000, GSI > > 0-23 > > [ 0.000000] smpboot: Allowing 128 CPUs, 64 hotplug CPUs > > This is your BIOS saying it needs 128 ids, 64 of which are 'empty'. > > I have a box like that as well, if it bothers you boot with: > "possible_cpus=64" or something. > OK, i got it. I thought that "cpu_possible_mask" strictly follows the rule: the number of CPUs in a system that physically are present.
Thanks, Peter! -- Vlad Rezki
