Lenovo T490 extremely show with Ubuntu 20.20 running kernel 5.8

Bug #1901406 reported by Henning Kulander on 2020-10-25
18
This bug affects 3 people
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Undecided
Unassigned

Bug Description

After upgrading from 20.04 to 20.20 on my laptop, the machine became extremely slow. After a days work I noticed that it never got any faster, and the machine was a lot colder than usual. Running cat /proc/cpuinfo and sudo cpupower frequency-info I noticed that the CPU was locked to 400Mhz.

After some googling I found reports of people having trouble with CPU frequency governors on kernel 5.8. I tried to add intel_pstate=active to grub, but that didn't help.

My short term workaround is to choose the old 5.4 kernel from 20.04. With this kernel everything is snappy again! Currently it's running at 3.2 Ghz with little load.

CPU info from /proc/cpuinfo (with kernel 5.4):

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 142
model name : Intel(R) Core(TM) i7-8665U CPU @ 1.90GHz
stepping : 12
microcode : 0xd6
cpu MHz : 4551.153
cache size : 8192 KB
physical id : 0
siblings : 8
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 22
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 art 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 3dnowprefetch cpuid_fault epb invpcid_single ssbd ibrs ibpb stibp ibrs_enhanced tpr_shadow vnmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt intel_pt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp md_clear flush_l1d arch_capabilities
bugs : spectre_v1 spectre_v2 spec_store_bypass swapgs taa itlb_multihit srbds
bogomips : 4199.88
clflush size : 64
cache_alignment : 64
address sizes : 39 bits physical, 48 bits virtual
power management:
---
ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu50
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: hennikul 2402 F.... pulseaudio
 /dev/snd/pcmC0D0p: hennikul 2402 F...m pulseaudio
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
DistroRelease: Ubuntu 20.10
InstallationDate: Installed on 2019-09-02 (418 days ago)
InstallationMedia: Ubuntu 19.04 "Disco Dingo" - Release amd64 (20190416)
MachineType: LENOVO 20N2CTO1WW
Package: linux (not installed)
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.8.0-25-generic root=UUID=a36f1344-fd6c-40ef-a397-57f5a57594df ro intel_pstate=active quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 5.8.0-25.26-generic 5.8.14
RelatedPackageVersions:
 linux-restricted-modules-5.8.0-25-generic N/A
 linux-backports-modules-5.8.0-25-generic N/A
 linux-firmware 1.190
Tags: groovy wayland-session
Uname: Linux 5.8.0-25-generic x86_64
UpgradeStatus: Upgraded to groovy on 2020-10-23 (2 days ago)
UserGroups: adm cdrom dip docker lpadmin plugdev sambashare sudo
_MarkForUpload: True
dmi.bios.date: 01/19/2020
dmi.bios.release: 1.61
dmi.bios.vendor: LENOVO
dmi.bios.version: N2IET83W (1.61 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20N2CTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40697 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.16
dmi.modalias: dmi:bvnLENOVO:bvrN2IET83W(1.61):bd01/19/2020:br1.61:efr1.16:svnLENOVO:pn20N2CTO1WW:pvrThinkPadT490:rvnLENOVO:rn20N2CTO1WW:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T490
dmi.product.name: 20N2CTO1WW
dmi.product.sku: LENOVO_MT_20N2_BU_Think_FM_ThinkPad T490
dmi.product.version: ThinkPad T490
dmi.sys.vendor: LENOVO

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1901406

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

Changed in linux (Ubuntu):
status: New → Incomplete
Jouni Mettala (jouni-mettala) wrote :

Could you test if this regression is fixed in mainline kernel?
https://wiki.ubuntu.com/Kernel/MainlineBuilds

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tags: added: apport-collected groovy wayland-session
description: updated

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Changed in linux (Ubuntu):
status: Incomplete → Confirmed
Henning Kulander (hennikul) wrote :

I tried installing
linux-image-unsigned-5.8.16-050816-generic_5.8.16-050816.202010170731_amd64.deb

This seems to work a little bit better than the Ubuntu kernel, but not much. I've seen the freqency reaching 1300Mhz (of 4800Mhz). Now it's running on 500Mhz while trying to load IntelliJ. Current load is 9.5, so I would expect it to be running at full speed now.

Jouni Mettala (jouni-mettala) wrote :

So far 5.8.14 is known bad version. 5.8.16 is bit better. Could you test middle point 5.8.15?

Could you also test new upstream version v5.10-rc1?
https://kernel.ubuntu.com/~kernel-ppa/mainline/?C=N;O=D

Henning Kulander (hennikul) wrote :

I couldn't find any builds in the 5.10-rc1 folder you linked to, but instead I tried 5.9.1-050901-generic #202010170731. The performance seems good and I get frequencies above 3000Mhz, so I think the problem is fixed here.

I would like to stress that the problem IS NOT fixed in 5.8.16, it's just marginally better. Not useable for production use. 5.9.1 and 5.4 are very useable! So I don't see the point in testing 5.8.15.

tags: added: kernel-fixed-upstream

I have the same problem but on a Lenovo ThinkPad P43s (Intel(R) Core(TM) i7-8665U CPU @ 1.90GHz).

matiaslaporte (matiaslaporte) wrote :

I just wanted to chime in and say I have the same problem, also with a T490, although the processor is i7-8565U CPU @ 1.80GHz and I am running Kubuntu 20.10. Currently running kernel 5.8.0-28.

If there's any way I can help, let me know.

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