Arch Linux

colinh

Member

Registered: 2014-08-23

Posts: 19

How to increase log level?

I'm new to Arch, so any comments on what I may have done wrong along the way are welcome.

I have a Dell XPS 13 (2015) and, in accordance with the Wiki page, I'm trying it with 4.1.2.

I uncommented "testing" in pacman.conf, did pacman -Sy, pacman -S linux [and its dependencies] and then commented "testing" out again. I also ran mkinitcpio -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux.img.

So, when the power cord is plugged in, everything works fine. But on battery I get total freezes after a couple of minutes (only the keyboard backlight key works).

I've had a look at journalctl (after setting LogLevel in systemd-system.conf to debug) but can't see anything unusual.

I tried adding "debug loglevel=7 console=tty2" to the kernel options, but that just scrambles the tty (and nothing seems to get printed there anyway).

What am I doing wrong? (probably quite a lot...

jasonwryan

Anarchist

From: .nz

Registered: 2009-05-09

Posts: 30,426

Website

Re: How to increase log level?

For one, never pacman -Sy $package. Second, don't selectively enable [testing].

For your log level, 7 is the correct value.

This all sounds like an X-y problem, though. Why are you doing this? What problem are you actually trying to solve (with the newer kernel, that is)?

---

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Registered Linux User #482438

karol

Archivist

Registered: 2009-05-06

Posts: 25,440

Re: How to increase log level?

As of kernel 4.0, there is still some manual configuration and kernel patching required, after which Arch should run smoothly. However, using 4.1 via linux-mainline (from the AUR) is recommended for the best experience.

If you're not having any problems using the stock kernel, no need to change it. linux-mainline from the AUR is a better choice that cherrypicking packages from [testing].

colinh

Member

Registered: 2014-08-23

Posts: 19

Re: How to increase log level?

Thanks for the info about not mixing core and stable. And for pointing out the XY problem.

It's actually more of an XYZ... problem :-)

X: kernel 4.0.6 is mostly OK (on a 2015 Dell XPS13) except for internal mic, lack of palm detect and a slight problem with waking up from sleep. The Arch Wiki page for this laptop recommends the linux-mainline AUR kernel, which was 4.1.2 when that page was written. These problems aren't critical though. I don't use the mic. I try to be careful about not touching the trackpad and the wakeup problem is fixed (I'm using i3wm) by a quick shift-alt-R.

Y: So I installed 4.1.2 (testing) [mistake]. That kernel solves the wakeup (and mic?) problems, but freezes/locks up on my laptop after a few minutes, without there being any indication of the problem that I could see in journalctl. This problem seems to be reported/solved(?) in a couple of other threads active now.

https://bbs.archlinux.org/viewtopic.php?id=199681
https://bbs.archlinux.org/viewtopic.php?id=199112

Z: But I'd still like to be able to get much more detailed debug/logging information.

Just adding "debug" to the kernel options(*) results in lots more output during boot.

(*) BTW, what's the proper term for these? Kernel parameters, kernel options, boot options, kernel boot options?

Adding console=tty2 doesn't work as expected. I still get the same output on tty0 (1?) before X (the display manager, lxdm) starts. After switching to tty2 (ctrl-alt-F2) all I see is a messed up screen (like what you sometimes get after sending random characters to a terminal - usually fixed by "reset") ie. all characters, including space, are replaced with some other graphics chars.

After blindly logging in on tty2, "reset" doesn't help. And there are no further debug/log messages (before or after logging in).

So I seem to be misunderstanding something :-(