Re: 5.4+: PAGE FAULT crashes the system multiple times per 24h

From: Udo van den Heuvel
Date: Tue Feb 11 2020 - 12:04:44 EST


On 10-02-2020 18:01, Gabriel C wrote:
> But try to boot a kernel with only what you need to boot when hunting bugs.
> As an example, if such a kernel works then you know for sure one of
> the option or a combination causes bugs.

These options are reasonable and necessary; so far things worked OK.
So why would they start being an issue?
And how can I even proceed when the kernel cannot find a rootfs anymore
while bisecting?
5.5.2 also has the page fault issue.
So why Linus does call 5.5.x 'stable' is beyond me.

How can I continue and find the root cause for the page fault hang?


> The force parameter is used to try to enable ACPI on HW has is OFF by
> default, you don't need that.

I booted 5.5.3 without acpi=force and dmesg output with `acpi` in it
looks similar.
So acpi=force wil be removed from future kernel commandlines.

>> We want to use discard on our ssd's.
>
> Use mount options?

Not enough to make it work for LUKS.

>> elevator=mq-deadline
>> We want a different scheduler for ssd versus hdd.
>
> If you really want that you should use udev rules for SSD/NVME/HDD/USB etc.

/etc/rc.d/rc.local is easier.
Look at the overhead of a service file.

Same as the overhead of NetworkManager versus a few kilobytes of
network-scripts.
But Fedora thinks otherwise....


Kind regards,
Udo