Aaaah, I can see plenty of this in syslog:

Oct 14 22:30:59 p5520 kernel: [ 9481.033687] CPU3: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.033688] CPU7: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.033718] CPU1: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.033719] CPU5: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.033720] CPU0: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.033720] CPU4: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.033722] CPU6: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.033722] CPU2: Package temperature above 
threshold, cpu clock throttled (total events = 5845)
Oct 14 22:30:59 p5520 kernel: [ 9481.034709] CPU3: Package temperature/speed 
normal
Oct 14 22:30:59 p5520 kernel: [ 9481.034710] CPU0: Package temperature/speed 
normal
Oct 14 22:30:59 p5520 kernel: [ 9481.034711] CPU4: Package temperature/speed 
normal
Oct 14 22:30:59 p5520 kernel: [ 9481.034711] CPU7: Package temperature/speed 
normal
Oct 14 22:30:59 p5520 kernel: [ 9481.034738] CPU2: Package temperature/speed 
normal
Oct 14 22:30:59 p5520 kernel: [ 9481.034738] CPU6: Package temperature/speed 
normal
Oct 14 22:30:59 p5520 kernel: [ 9481.034739] CPU1: Package temperature/speed 
normal
Oct 14 22:30:59 p5520 kernel: [ 9481.034740] CPU5: Package temperature/speed 
normal


So maybe it THINKS it overheats (although it does NOT) and throttles down...

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1797802

Title:
  Erratic behavior of intel pstate CPU frequency control

Status in linux package in Ubuntu:
  Incomplete

Bug description:
  I noticed that sometimes my Ubuntu 18.10 system feels sluggish. The
  other times everything works fine. I don't know what triggers this
  weird state. Suspend / resume? Maybe.

  At first I thought this was maybe just a "perception issue", but then
  when the sluggishness happened again, I fired up i7z and it looks that
  CPU frequency almost never got over ~1600 MHz, But my CPU is perfectly
  capable of going up to 4000 MHz!

  I tried to fix it by setting 
  echo 80 > /sys/devices/system/cpu/intel_pstate/min_perf_pct
  echo 80 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

  I hoped I would force the CPU into almost max performance state this
  way. And indeed, once I ran these commands, i7z showed steady 3100+
  MHz on all cores.

  Then something weird happened - when I run some mild load on the CPU,
  like just starting the IDE, during the startup the frequency **
  dropped back to about 800-1600 MHz ** and returned to 3100 MHz after
  the load was gone (IDE loaded).

  The CPU core temperatures shown by sensors / i7z are ok and typically
  at about 40-50 C when this slowdown happens, so this doesn't look like
  thermal throttling.

  Any ideas?

  ProblemType: Bug
  DistroRelease: Ubuntu 18.10
  Package: linux-image-4.18.0-10-generic 4.18.0-10.11
  ProcVersionSignature: Ubuntu 4.18.0-10.11-generic 4.18.12
  Uname: Linux 4.18.0-10-generic x86_64
  ApportVersion: 2.20.10-0ubuntu13
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  pkolaczk   3281 F.... pulseaudio
   /dev/snd/pcmC0D0c:   pkolaczk   3281 F...m pulseaudio
  CurrentDesktop: ubuntu:GNOME
  Date: Sun Oct 14 22:16:50 2018
  DistributionChannelDescriptor:
   # This is a distribution channel descriptor
   # For more information see 
http://wiki.ubuntu.com/DistributionChannelDescriptor
   canonical-oem-somerville-xenial-amd64-20160624-2
  HibernationDevice: RESUME=UUID=4836842e-0116-43c4-98b4-7a56427f81f1
  InstallationDate: Installed on 2017-04-12 (549 days ago)
  InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 
20160624-10:47
  MachineType: Dell Inc. Precision 5520
  ProcEnviron:
   TERM=xterm-256color
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=pl_PL.UTF-8
   SHELL=/bin/bash
  ProcFB: 0 inteldrmfb
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-10-generic 
root=UUID=7f76b1f0-8fef-41cc-86a2-99e554cb4d40 ro acpi_rev_override quiet 
splash iwlwifi.power_save=1 crashkernel=384M-:128M crashkernel=384M-:128M 
vt.handoff=1
  RelatedPackageVersions:
   linux-restricted-modules-4.18.0-10-generic N/A
   linux-backports-modules-4.18.0-10-generic  N/A
   linux-firmware                             1.175
  SourcePackage: linux
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 07/24/2018
  dmi.bios.vendor: Dell Inc.
  dmi.bios.version: 1.11.0
  dmi.board.name: 06X96V
  dmi.board.vendor: Dell Inc.
  dmi.board.version: A00
  dmi.chassis.type: 10
  dmi.chassis.vendor: Dell Inc.
  dmi.modalias: 
dmi:bvnDellInc.:bvr1.11.0:bd07/24/2018:svnDellInc.:pnPrecision5520:pvr:rvnDellInc.:rn06X96V:rvrA00:cvnDellInc.:ct10:cvr:
  dmi.product.family: Precision
  dmi.product.name: Precision 5520
  dmi.product.sku: 07BF
  dmi.sys.vendor: Dell Inc.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1797802/+subscriptions

-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to