Bug 2295026 - 6.8 kernel see all cpus, 6.9 only sees 1 cpu
Summary: 6.8 kernel see all cpus, 6.9 only sees 1 cpu
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel
Version: 40
Hardware: x86_64
OS: Linux
unspecified
high
Target Milestone: ---
Assignee: Fernando F. Mancera
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-07-01 19:38 UTC by jimccann
Modified: 2025-02-13 17:19 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2025-02-13 17:19:08 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)
boot of kernel 6.8.11 (121.57 KB, text/plain)
2024-07-01 19:38 UTC, jimccann
no flags Details
6.9.6 booted (122.86 KB, text/plain)
2024-07-01 20:09 UTC, jimccann
no flags Details

Description jimccann 2024-07-01 19:38:37 UTC
Created attachment 2038652 [details]
boot of kernel 6.8.11

Created attachment 2038652 [details]
boot of kernel 6.8.11

1. Please describe the problem:

I updated the kernel and new kernel only allows 1 cpu.


2. What is the Version-Release number of the kernel:
Linux 6.8.11-300.fc40.x86_64 to kernel-6.9.6-200.fc40.x86_64

3. Did it work previously in Fedora? If so, what kernel version did the issue
   *first* appear?  kernel-6.9.5-200.fc40.x86_64 (I think)

4. Can you reproduce this issue? If so, please provide the steps to reproduce
   the issue below: If I boot into 6.8.11 kernel I have 16 cpu show up in top. If I boot to 6.9.6 I only get 1 cpu in top.


5. Does this problem occur with the latest Rawhide kernel? Not sure.

6. Are you running any modules that not shipped with directly Fedora's kernel?: Nope.


7. Please attach the kernel logs. Done. With both kernels listed.

Comment 1 jimccann 2024-07-01 20:09:36 UTC
Created attachment 2038654 [details]
6.9.6 booted

Comment 2 jimccann 2024-07-01 20:12:03 UTC
Interesting....

Jul 01 12:03:44 kernel: TSC deadline timer available
Jul 01 12:03:44 kernel: CPU topo: Max. logical packages:   1
Jul 01 12:03:44 kernel: CPU topo: Max. logical dies:       1
Jul 01 12:03:44 kernel: CPU topo: Max. dies per package:   1
Jul 01 12:03:44 kernel: CPU topo: Max. threads per core:   1
Jul 01 12:03:44 kernel: CPU topo: Num. cores per package:     1
Jul 01 12:03:44 kernel: CPU topo: Num. threads per package:   1
Jul 01 12:03:44 kernel: CPU topo: Allowing 1 present CPUs plus 0 hotplug CPUs
Jul 01 12:03:44 kernel: CPU topo: Rejected CPUs 15

Comment 3 jimccann 2024-07-25 16:06:31 UTC
Any updates? Any comments?

Comment 4 Fernando F. Mancera 2024-08-13 21:05:14 UTC
Hi! Was the issue fixed with the latest updates? I am now digging into logs although this is not my area of expertise so it may take a lot :)

Comment 5 bighuskysf 2024-08-15 17:12:41 UTC
Issue is still present all the way to kernel 6.10.4

Here on a MacBook Pro 11,3 from late 2013

It seems to be a Fedora/RedHat specific issue, as other distros with kernels 6.9.x and 6.10.x all work fine.

Am still hoping for a fix, otherwise I will have to say goodbye to Fedora.

Comment 6 Fernando F. Mancera 2024-08-22 13:41:53 UTC
Thank you for confirming. I am working on it currently. Will let you know my findings.

Comment 7 Fernando F. Mancera 2024-08-22 14:01:46 UTC
Could you both provide `lscpu` command full output - it would be very useful for me to have all the details of your CPU.

Comment 8 bighuskysf 2024-08-22 15:44:27 UTC
> Fedora 40 - Kernel 6.8.11
> -------------------------
> 00:00.0 Host bridge: Intel Corporation Crystal Well DRAM Controller (rev 08)
> 00:01.0 PCI bridge: Intel Corporation Crystal Well PCI Express x16 Controller (rev 08)
> 00:01.1 PCI bridge: Intel Corporation Crystal Well PCI Express x8 Controller (rev 08)
> 00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05)
> 00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
> 00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
> 00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5)
> 00:1c.2 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3 (rev d5)
> 00:1c.3 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4 (rev d5)
> 00:1c.4 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #5 (rev d5)
> 00:1f.0 ISA bridge: Intel Corporation HM87 Express LPC Controller (rev 05)
> 00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 05)
> 01:00.0 VGA compatible controller: NVIDIA Corporation GK107M [GeForce GT 750M Mac Edition] (rev a1)
> 01:00.1 Audio device: NVIDIA Corporation GK107 HDMI Audio Controller (rev a1)
> 03:00.0 Network controller: Broadcom Inc. and subsidiaries BCM4360 802.11ac Dual Band Wireless Network Adapter (rev 03)
> 04:00.0 Multimedia controller: Broadcom Inc. and subsidiaries 720p FaceTime HD Camera
> 05:00.0 SATA controller: Samsung Electronics Co Ltd S4LN053X01 AHCI SSD Controller(Apple slot) (rev 01)
> 06:00.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:00.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:03.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:04.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:05.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:06.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 08:00.0 System peripheral: Intel Corporation DSL5520 Thunderbolt 2 NHI [Falcon Ridge 4C 2013]
> ======================================================================
> cat /proc/cpuinfo 
> processor	: 0
> vendor_id	: GenuineIntel
> cpu family	: 6
> model		: 70
> model name	: Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
> stepping	: 1
> microcode	: 0x1c
> cpu MHz		: 2593.451
> cache size	: 6144 KB
> physical id	: 0
> siblings	: 8
> core id		: 0
> cpu cores	: 4
> apicid		: 0
> initial apicid	: 0
> fpu		: yes
> fpu_exception	: yes
> cpuid level	: 13
> wp		: yes
> flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm cpuid_fault epb pti ssbd ibrs ibpb stibp tpr_shadow flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt dtherm ida arat pln pts vnmi md_clear flush_l1d
> vmx flags	: vnmi preemption_timer invvpid ept_x_only ept_ad ept_1gb flexpriority tsc_offset vtpr mtf vapic ept vpid unrestricted_guest ple shadow_vmcs
> bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit srbds mmio_unknown
> bogomips	: 5188.08
> clflush size	: 64
> cache_alignment	: 64
> address sizes	: 39 bits physical, 48 bits virtual
> power management:
> 
> processor	: 1
> vendor_id	: GenuineIntel
> ...
> 
> processor	: 2
> vendor_id	: GenuineIntel
> ...
> 
> processor	: 3
> vendor_id	: GenuineIntel
> ...
> 
> processor	: 4
> vendor_id	: GenuineIntel
> ...
> 
> processor	: 5
> vendor_id	: GenuineIntel
> ...
> 
> processor	: 6
> vendor_id	: GenuineIntel
> ...
> 
> processor	: 7
> vendor_id	: GenuineIntel
> ...
> ======================================================================
> kernel: smpboot: Allowing 8 CPUs, 0 hotplug CPUs
> kernel: setup_percpu: NR_CPUS:8192 nr_cpumask_bits:8 nr_cpu_ids:8 nr_node_ids:1
> kernel: SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=8, Nodes=1
> kernel: rcu:         RCU restricting CPUs from NR_CPUS=8192 to nr_cpu_ids=8.
> kernel: smpboot: CPU0: Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz (family: 0x6, model: 0x46, stepping: 0x1)
> kernel: .... node  #0, CPUs:      #1 #2 #3 #4 #5 #6 #7
> kernel: smp: Brought up 1 node, 8 CPUs
> 
> Fedora 40 - Kernel 6.10.4
> -------------------------
> 00:00.0 Host bridge: Intel Corporation Crystal Well DRAM Controller (rev 08)
> 00:01.0 PCI bridge: Intel Corporation Crystal Well PCI Express x16 Controller (rev 08)
> 00:01.1 PCI bridge: Intel Corporation Crystal Well PCI Express x8 Controller (rev 08)
> 00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05)
> 00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
> 00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
> 00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5)
> 00:1c.2 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3 (rev d5)
> 00:1c.3 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4 (rev d5)
> 00:1c.4 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #5 (rev d5)
> 00:1f.0 ISA bridge: Intel Corporation HM87 Express LPC Controller (rev 05)
> 00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 05)
> 01:00.0 VGA compatible controller: NVIDIA Corporation GK107M [GeForce GT 750M Mac Edition] (rev a1)
> 01:00.1 Audio device: NVIDIA Corporation GK107 HDMI Audio Controller (rev a1)
> 03:00.0 Network controller: Broadcom Inc. and subsidiaries BCM4360 802.11ac Dual Band Wireless Network Adapter (rev 03)
> 04:00.0 Multimedia controller: Broadcom Inc. and subsidiaries 720p FaceTime HD Camera
> 05:00.0 SATA controller: Samsung Electronics Co Ltd S4LN053X01 AHCI SSD Controller(Apple slot) (rev 01)
> 06:00.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:00.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:03.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:04.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:05.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 07:06.0 PCI bridge: Intel Corporation DSL5520 Thunderbolt 2 Bridge [Falcon Ridge 4C 2013]
> 08:00.0 System peripheral: Intel Corporation DSL5520 Thunderbolt 2 NHI [Falcon Ridge 4C 2013]
> ======================================================================
> cat /proc/cpuinfo 
> processor	: 0
> vendor_id	: GenuineIntel
> cpu family	: 6
> model		: 70
> model name	: Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
> stepping	: 1
> microcode	: 0x1c
> cpu MHz		: 3591.625
> cache size	: 6144 KB
> physical id	: 0
> siblings	: 1
> core id		: 0
> cpu cores	: 1
> apicid		: 0
> initial apicid	: 0
> fpu		: yes
> fpu_exception	: yes
> cpuid level	: 13
> wp		: yes
> flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm cpuid_fault epb pti ssbd ibrs ibpb stibp tpr_shadow flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt dtherm ida arat pln pts vnmi md_clear flush_l1d
> vmx flags	: vnmi preemption_timer invvpid ept_x_only ept_ad ept_1gb flexpriority tsc_offset vtpr mtf vapic ept vpid unrestricted_guest ple shadow_vmcs
> bugs		: cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit srbds mmio_unknown
> bogomips	: 5187.91
> clflush size	: 64
> cache_alignment	: 64
> address sizes	: 39 bits physical, 48 bits virtual
> power management:
> ======================================================================
> kernel: CPU topo: Limiting to 1 possible CPUs
> kernel: CPU topo: CPU limit of 1 reached. Ignoring further CPUs
> kernel: CPU topo: Max. logical packages:   1
> kernel: CPU topo: Max. logical dies:       1
> kernel: CPU topo: Max. dies per package:   1
> kernel: CPU topo: Max. threads per core:   1
> kernel: CPU topo: Num. cores per package:     1
> kernel: CPU topo: Num. threads per package:   1
> kernel: CPU topo: Allowing 1 present CPUs plus 0 hotplug CPUs
> kernel: CPU topo: Rejected CPUs 7

Comment 9 jimccann 2024-08-24 02:17:46 UTC
jimb0@fedora:~$ lscpu
Architecture:             x86_64
  CPU op-mode(s):         32-bit, 64-bit
  Address sizes:          39 bits physical, 48 bits virtual
  Byte Order:             Little Endian
CPU(s):                   16
  On-line CPU(s) list:    0-15
Vendor ID:                GenuineIntel
  Model name:             11th Gen Intel(R) Core(TM) i7-11700F @ 2.50GHz
    CPU family:           6
    Model:                167
    Thread(s) per core:   2
    Core(s) per socket:   8
    Socket(s):            1
    Stepping:             1
    CPU(s) scaling MHz:   41%
    CPU max MHz:          4900.0000
    CPU min MHz:          800.0000
    BogoMIPS:             4992.00
    Flags:                fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology 
                          nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_l
                          m abm 3dnowprefetch cpuid_fault epb ssbd ibrs ibpb stibp ibrs_enhanced tpr_shadow flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap avx512ifma 
                          clflushopt intel_pt avx512cd sha_ni avx512bw avx512vl xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp hwp_pkg_req vnmi avx512vbmi umip pku ospke avx512_vbmi2 gfni vaes
                           vpclmulqdq avx512_vnni avx512_bitalg avx512_vpopcntdq rdpid fsrm md_clear flush_l1d arch_capabilities
Virtualization features:  
  Virtualization:         VT-x
Caches (sum of all):      
  L1d:                    384 KiB (8 instances)
  L1i:                    256 KiB (8 instances)
  L2:                     4 MiB (8 instances)
  L3:                     16 MiB (1 instance)
NUMA:                     
  NUMA node(s):           1
  NUMA node0 CPU(s):      0-15
Vulnerabilities:          
  Gather data sampling:   Mitigation; Microcode
  Itlb multihit:          Not affected
  L1tf:                   Not affected
  Mds:                    Not affected
  Meltdown:               Not affected
  Mmio stale data:        Mitigation; Clear CPU buffers; SMT vulnerable
  Reg file data sampling: Not affected
  Retbleed:               Mitigation; Enhanced IBRS
  Spec rstack overflow:   Not affected
  Spec store bypass:      Mitigation; Speculative Store Bypass disabled via prctl
  Spectre v1:             Mitigation; usercopy/swapgs barriers and __user pointer sanitization
  Spectre v2:             Mitigation; Enhanced / Automatic IBRS; IBPB conditional; RSB filling; PBRSB-eIBRS SW sequence; BHI SW loop, KVM SW loop
  Srbds:                  Not affected
  Tsx async abort:        Not affected
jimb0@fedora:~$

Comment 10 bighuskysf 2024-08-24 17:54:05 UTC
Hi
had mistyped the commands in my previous post. Here for completeness

6.10.4
------
Architecture:             x86_64
  CPU op-mode(s):         32-bit, 64-bit
  Address sizes:          39 bits physical, 48 bits virtual
  Byte Order:             Little Endian
CPU(s):                   1
  On-line CPU(s) list:    0
Vendor ID:                GenuineIntel
  BIOS Vendor ID:         Intel(R) Corporation
  Model name:             Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
    BIOS Model name:      Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz  CPU @ 2.6GH
                          z
    BIOS CPU family:      198
    CPU family:           6
    Model:                70
    Thread(s) per core:   1
    Core(s) per socket:   1
    Socket(s):            1
    Stepping:             1
    CPU(s) scaling MHz:   95%
    CPU max MHz:          3800.0000
    CPU min MHz:          800.0000
    BogoMIPS:             5187.71
    Flags:                fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge m
                          ca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 s
                          s ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc 
                          arch_perfmon pebs bts rep_good nopl xtopology nonstop_
                          tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_c
                          pl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid 
                          sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer a
                          es xsave avx f16c rdrand lahf_lm abm cpuid_fault epb p
                          ti ssbd ibrs ibpb stibp tpr_shadow flexpriority ept vp
                          id ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms
                           invpcid xsaveopt dtherm ida arat pln pts vnmi md_clea
                          r flush_l1d
Virtualization features:  
  Virtualization:         VT-x
Caches (sum of all):      
  L1d:                    32 KiB (1 instance)
  L1i:                    32 KiB (1 instance)
  L2:                     256 KiB (1 instance)
  L3:                     6 MiB (1 instance)
  L4:                     128 MiB (1 instance)
NUMA:                     
  NUMA node(s):           1
  NUMA node0 CPU(s):      0
Vulnerabilities:          
  Gather data sampling:   Not affected
  Itlb multihit:          KVM: Mitigation: VMX disabled
  L1tf:                   Mitigation; PTE Inversion; VMX conditional cache flush
                          es, SMT disabled
  Mds:                    Mitigation; Clear CPU buffers; SMT disabled
  Meltdown:               Mitigation; PTI
  Mmio stale data:        Unknown: No mitigations
  Reg file data sampling: Not affected
  Retbleed:               Not affected
  Spec rstack overflow:   Not affected
  Spec store bypass:      Mitigation; Speculative Store Bypass disabled via prct
                          l
  Spectre v1:             Mitigation; usercopy/swapgs barriers and __user pointe
                          r sanitization

=================================================================================
6.8.11
------Architecture:             x86_64
  CPU op-mode(s):         32-bit, 64-bit
  Address sizes:          39 bits physical, 48 bits virtual
  Byte Order:             Little Endian
CPU(s):                   8
  On-line CPU(s) list:    0-7
Vendor ID:                GenuineIntel
  Model name:             Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
    CPU family:           6
    Model:                70
    Thread(s) per core:   2
    Core(s) per socket:   4
    Socket(s):            1
    Stepping:             1
    CPU(s) scaling MHz:   95%
    CPU max MHz:          3800.0000
    CPU min MHz:          800.0000
    BogoMIPS:             5188.04
    Flags:                fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge m
                          ca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 s
                          s ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc 
                          arch_perfmon pebs bts rep_good nopl xtopology nonstop_
                          tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_c
                          pl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid 
                          sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer a
                          es xsave avx f16c rdrand lahf_lm abm cpuid_fault epb p
                          ti ssbd ibrs ibpb stibp tpr_shadow flexpriority ept vp
                          id ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms
                           invpcid xsaveopt dtherm ida arat pln pts vnmi md_clea
                          r flush_l1d
Virtualization features:  
  Virtualization:         VT-x
Caches (sum of all):      
  L1d:                    128 KiB (4 instances)
  L1i:                    128 KiB (4 instances)
  L2:                     1 MiB (4 instances)
  L3:                     6 MiB (1 instance)
  L4:                     128 MiB (1 instance)
NUMA:                     
  NUMA node(s):           1
  NUMA node0 CPU(s):      0-7
Vulnerabilities:          
  Gather data sampling:   Not affected
  Itlb multihit:          KVM: Mitigation: VMX disabled
  L1tf:                   Mitigation; PTE Inversion; VMX conditional cache flush
                          es, SMT vulnerable
  Mds:                    Mitigation; Clear CPU buffers; SMT vulnerable
  Meltdown:               Mitigation; PTI
  Mmio stale data:        Unknown: No mitigations
  Reg file data sampling: Not affected
  Retbleed:               Not affected
  Spec rstack overflow:   Not affected
  Spec store bypass:      Mitigation; Speculative Store Bypass disabled via prct
                          l
  Spectre v1:             Mitigation; usercopy/swapgs barriers and __user pointe
                          r sanitization
  Spectre v2:             Mitigation; Retpolines; IBPB conditional; IBRS_FW; STI
                          BP conditional; RSB filling; PBRSB-eIBRS Not affected;
                           BHI Not affected
  Srbds:                  Mitigation; Microcode
  Tsx async abort:        Not affected

Comment 11 Fernando F. Mancera 2024-08-28 16:21:52 UTC
So just to provide an update. I am investigating why the kernel is limiting the number of CPUs to 1. So far I have found that "noapic" option is set and therefore that limits the number of CPUs to 1. I need to understand if noapic is being disabled on kernel configuration or runtime.

As this is not affecting everyone I suspect that is being set during runtime for some reason. Working on it now :)

Comment 12 Fernando F. Mancera 2024-08-28 16:29:38 UTC
Okay after some investigation, I noticed CPU management was reworked on 6.9 so..

7c0edad3643f4493c4dafa6f5dfcfb1a86432156 is very likely to be the one causing the issue. Or the series in general.

I am trying to follow the logic here and send a patch to understand what is going on. Non a trivial issue for me, sorry for the delay.

Comment 13 Fernando F. Mancera 2024-08-28 16:40:49 UTC
Jul 01 12:03:44 kernel: Command line: BOOT_IMAGE=(hd4,gpt5)/vmlinuz-6.9.6-200.fc40.x86_64 root=UUID=afc021ed-0d53-457c-ab05-b130e8c1abd4 ro rootflags=subvol=root noapic rhgb quiet

Yeah, this is booting with noapic option. I am investigating why is so.

Did any of you added this manually by any chance?

Comment 14 Fernando F. Mancera 2024-08-28 17:23:46 UTC
So a workaround would be to follow these steps:


- Get your default kernel:
$ sudo grubby --default-kernel
/boot/vmlinuz-6.10.0-rc2+

- Get your current boot options, please notice the "args" section
$ sudo grubby --info /boot/vmlinuz-6.10.0-rc2+
index=2
kernel="/boot/vmlinuz-6.10.0-rc2+"
args="quiet ro rootflags=subvol=root rhgb quite noapic"
root="UUID=fc905b42-6f41-4dbd-a554-1c714964b150"
initrd="/boot/initramfs-6.10.0-rc2+.img"
title="Fedora Linux (6.10.0-rc2+) 41 (Workstation Edition Prerelease)"
id="a48e46ceb39c496dac2991362099ac07-6.10.0-rc2+"

- Update your boot options, add the same args but remove "noapic" from the list
$ sudo grubby --args="ro rootflags=subvol=root rhgb quite" --update-kernel /boot/vmlinuz-6.10.0-rc2+

Then reboot.

That should solve your issue. Please, let me know your results. I am now investigating why noapic boot option is set :/

Comment 15 Fernando F. Mancera 2024-08-28 17:28:06 UTC
Oh, there is an errata on my latest comment. To remove the argument you need to do:

sudo grubby --remove-args="noapic" --update-kernel "/boot/vmlinuz-6.10.0-rc2+"

:)

Comment 16 jimccann 2024-09-06 20:47:26 UTC
So I did this command:

sudo grubby --remove-args="noapic" --update-kernel /boot/vmlinuz-6.10.7-200.fc40.x86_64 

Then TRIED to boot. It would just hang at the kernel. I then booted to my 6.8 kernel (all good)

Then did this command:

 sudo grubby --args="noapic" --update-kernel /boot/vmlinuz-6.10.7-200.fc40.x86_64

Then it booted up to 6.10 kernel but only 1 cpu. But during the booting process I noticed this error that I don't see when booting 6.8:

snd_hda_intel: 0000:00:1f.3: azx_get_response timeout, switching to single_cmd mode: last cmd=0x00836013


So still on 6.8 kernel at this time all cpus showing up.

Comment 17 Fernando F. Mancera 2024-09-07 09:11:49 UTC
Ah yes, that could happen. Some BIOS and CPUs do not get along with APIC and therefore they require the "noapic" option to work.

Anyway, I noticed there was a change in behavior from 6.8 to 6.9 and I've sent a patch to the kernel mailing list. Let's see what the maintainers think about this. https://lkml.org/lkml/2024/9/7/160

Comment 18 jimccann 2024-11-27 15:57:29 UTC
Curious and updates on the patch?

Comment 19 jimccann 2024-11-27 19:22:29 UTC
I think I found a solution that seems to be working.


jimb0@fedora:~$ sudo grubby --default-kernel
[sudo] password for jimb0: 
/boot/vmlinuz-6.11.8-200.fc40.x86_64
jimb0@fedora:~$ sudo grubby --remove-args="noapic" --update-kernel /boot/vmlinuz-6.11.8-200.fc40.x86_64 
jimb0@fedora:~$ sudo grubby --args="pci=nobar" --update-kernel /boot/vmlinuz-6.11.8-200.fc40.x86_64 
jimb0@fedora:~$ sudo grubby --info /boot/vmlinuz-6.11.8-200.fc40.x86_64
index=0
kernel="/boot/vmlinuz-6.11.8-200.fc40.x86_64"
args="ro rootflags=subvol=root rhgb quiet pci=nobar"
root="UUID=afc021ed-0d53-457c-ab05-b130e8c1abd4"
initrd="/boot/initramfs-6.11.8-200.fc40.x86_64.img"
title="Fedora Linux (6.11.8-200.fc40.x86_64) 40 (Workstation Edition)"
id="201c5c772cd648fa82fbcd70a27a6821-6.11.8-200.fc40.x86_64"
jimb0@fedora:~$ 

jimb0@fedora:~$ cat /proc/version 
Linux version 6.11.8-200.fc40.x86_64 (mockbuild@45b8acd92af44838bf2fb82dcc691ec7) (gcc (GCC) 14.2.1 20240912 (Red Hat 14.2.1-3), GNU ld version 2.41-37.fc40) #1 SMP PREEMPT_DYNAMIC Thu Nov 14 20:38:18 UTC 2024
jimb0@fedora:~$ 

I see all cpus (not just 1 cpu)

jimb0@fedora:~$ lscpu |grep 'CPU(s)'
CPU(s):                               16
On-line CPU(s) list:                  0-15
CPU(s) scaling MHz:                   23%
NUMA node0 CPU(s):                    0-15
jimb0@fedora:~$ 


System Information
	Manufacturer: HP
	Product Name: HP Pavilion Desktop TP01-2xxx
	Version:  
	UUID: 912c5ede-63c6-9d2a-ff01-ea2893bf6187
	Wake-up Type: Power Switch
	SKU Number: 318B0AA#ABA
	Family: 103C_53311M HP Pavilion Desktop PC

Comment 20 Fernando F. Mancera 2024-12-02 14:38:52 UTC
There are comments now: https://lore.kernel.org/lkml/87ttbnv75j.ffs@tglx/

I am sending a v2 now.

Comment 21 Fernando F. Mancera 2025-02-13 17:19:08 UTC
It is fixed now in F40, F41 and Rawhide.


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