CPU temperature increase for no apparent reasons after upgrading to Kernel 4.10 (from 4.8)

I am monitoring my machine using telegraf and collectd, and displaying the information in Grafana.

In the last week, the CPU temperature is a constant 35°C (average). But after upgrading to Kernel 4.10 the temperature raises to a constant 40°C (average). That's quite a significant bump. However, the frequency of the CPU is not changed, the machine load and CPU utilisation is rather stable, Disk activity and temperature is also stable, ambient (cabinet) temperature is also stable. So no apparent reason for this increase. In addition reverting back to Kernel 4.8 restore a stable 35°C CPU temperature.

The CPU temperature is monitored using libsensors. Running the command `sensors` is consistant with what my monitoring stack recorded. Grepping the /sys pseudo-filesystem for the temperature (e.g. /sys/bus/pci/drivers/k10temp/0000:00:18.3/hwmon/hwmon3/temp1_input) returns also consistant temperature.

When I boot to the "older" kernel (e.g. 4.8), the temperature returns to previous level (i.-e. 35°C).

I have no external means to verify if the CPU temperature is really 35 and 40°C. So I cannot tell if Kernel 4.8 (and 4.4) is simply reporting the temperature correctly (so the CPU is indeed 35°C) or incorrectly (the CPU is perhaps 40°C or other values). Same comment for Kernel 4.10.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-generic-hwe-16.04 4.10.0.27.30
ProcVersionSignature: Ubuntu 4.8.0-58.63~16.04.1-generic 4.8.17
Uname: Linux 4.8.0-58-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
Date: Mon Jul 24 12:51:04 2017
InstallationDate: Installed on 2014-02-09 (1260 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140208)
JournalErrors:
 Error: command ['journalctl', '-b', '--priority=warning', '--lines=1000'] failed with exit code 1: Hint: You are currently not seeing messages from other users and the system.
       Users in the 'systemd-journal' group can see all messages. Pass -q to
       turn off this notice.
 No journal files were opened due to insufficient permissions.
SourcePackage: linux-meta-hwe
UpgradeStatus: Upgraded to xenial on 2016-03-20 (490 days ago)