On 7/3/20 5:57 PM, 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 > [ 0.000000] setup_percpu: NR_CPUS:512 nr_cpumask_bits:512 nr_cpu_ids:128 > nr_node_ids:1
My 3950 do [ 0.005271] ACPI: SSDT 0x00000000CA1F5000 0003F1 (v02 ALASKA CPUSSDT 01072009 AMI 01072009) [ 0.108266] smpboot: Allowing 32 CPUs, 0 hotplug CPUs [ 0.111384] setup_percpu: NR_CPUS:8192 nr_cpumask_bits:32 nr_cpu_ids:32 nr_node_ids:1 (Fedora F32 5.6.18-300) What motherboard and BIOs do you use? > ... > [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=128, Nodes=1 > [ 0.000000] rcu: RCU restricting CPUs from NR_CPUS=512 to > nr_cpu_ids=128. > [ 0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=128 > urezki@pc638:~$ > <snip> > > For example SLUB thinks that it deals with 128 CPUs in the system what is > wrong if i do not miss something. Since nr_cpu_ids is broken(?), thus the > "cpu_possible_mask" does not correspond to reality as well. > > Any thoughts? > > Thanks! > > -- > Vlad Rezki
