Intel bug freeze OPNsense and the solution

[ednt]

We were again unlucky!

After the problems with bridge and CARP on the same interface (-> kernel freeze)
we run into an other problem:

A new OPNsense always freeze at around 3am in the morning every day.

After a long time of searching and thinking we found the bug and a solution.

The bug:

Intel build a series of CPUs wich crash if they switch to idle state C2.
See here:

https://en.wikipedia.org/wiki/Silvermont

And look at Bay Trail issues on FreeBSD

Unfortunalty we used a mainboard with an J1900 CPU

You can check the current settings with

sysctl -a |grep cx

You can resolv that issue with entries in /etc/sysctl.conf

hw.acpi.cpu.cx_lowest=C1
dev.cpu.0.cx_lowest=C1
dev.cpu.1.cx_lowest=C1
dev.cpu.2.cx_lowest=C1
dev.cpu.3.cx_lowest=C1

To activate it by hand:

sysctl -f /etc/sysctl.conf

After a reboot this is done automatically.

This prevent the CPU to go in idle state C2 an it resolved our freeze problem.

[dphonov2]

What was your resolution to kernel freeze when running a bridge and CARP at the same time?

I seem to be exxperiencing the same thing.

No freezes until I enabled a VxLan and bridged my relevant interfaces.

Now, at some random interval, OPNSense just locks up.