[Solved] Thermald and kernel 3.18.2 – CPU stalls

flannelhead · 2015-01-15 19:23:20

After today's update to kernel 3.18.2, my system went into an unusable state. Sometimes it wouldn't even get into X (I have autologin to X enabled), sometimes I could open Firefox and then X server locked up. However, in that state the system still responded to the power button and started the shutdown process. The shutdown then stuck because systemd was waiting for some services to shut down. During the waiting, I got kernel messages like the following:

Jan 15 13:28:42 laatumasiina kernel: INFO: rcu_preempt detected stalls on CPUs/tasks: {} (detected by 3, t=18002 jiffies, g=-112, c=-113, q=6604)
Jan 15 13:29:42 laatumasiina kernel: INFO: rcu_preempt self-detected stall on CPU { 3}  (t=18000 jiffies g=-111 c=-112 q=7220)
Jan 15 13:32:42 laatumasiina kernel: INFO: rcu_preempt self-detected stall on CPU { 3}  (t=72003 jiffies g=-111 c=-112 q=8979)

So apparently everything wasn't right with the CPUs. I tried disabling some kernel parameters, systemd services which could affect the kernel somehow etc. Finally, I noticed that disabling thermald (I'm using it because I'm on a laptop) helped – I've now run the new kernel for a good while, doing everyday tasks with no lockups. Furthermore, I tested running thermald manually, and indeed I experienced the same kind of lockup again. I also tested thermald-git, which gave the same problems.

I'm posting this just in case anyone else has the same problems with the new kernel and thermald. So the temporary solution seems to be disabling thermald. I'm going to see if this issue persists with future kernel versions. If it does, I'll file an issue on GitHub. Too bad it is quite hard to provide debug information about this, because the lockups are somewhat random. Should anyone have a clue of what might be happening, I'm all ears and willing to give debug information. I don't really know where to start, because debugging low level kernel issues is a completely new regime for me and it's a bit hard to find where to start.

If you think this belongs to the AUR subforum, don't hesitate to move it.

E: forgot to add information about hardware. This is happening on an Asus Zenbook UX32VD. The CPU is Intel i5-3317U.

UPDATE: The problem seems to be gone with kernel 3.19.2.

Last edited by flannelhead (2015-03-22 20:58:17)

WonderWoofy · 2015-01-16 05:58:12

It seems like your goal with this post is to try to help others seeing something similar. In that case, it would probably be a good idea to post your hardware info as well. Namely, your processor make and model would be good.

As a side note, I'll mention that my Minnowboard MAX with an Intel Atom E3825 seems to be working fine with thermald and 3.8.*

flannelhead · 2015-01-16 16:55:59

WonderWoofy wrote:

It seems like your goal with this post is to try to help others seeing something similar. In that case, it would probably be a good idea to post your hardware info as well. Namely, your processor make and model would be good.
As a side note, I'll mention that my Minnowboard MAX with an Intel Atom E3825 seems to be working fine with thermald and 3.8.*

Yep, thanks for notifying. I added the CPU model to the top post.

Also, I'm now running linux-mainline 3.19rc4, and haven't seen those hiccups so far. So luckily, this issue might not be anything too permanent and it's likely already fixed in mainline. I'll wait for the next few kernel upgrades and mark this thread as solved when I can run thermald on the official kernel again.

boxofrox · 2015-01-31 18:05:20

Thanks, flannelhead. You're a life saver. I just got bit by this exact same problem when I upgraded my kernel from 3.17.4 to 3.18.4.

Also on Asus Zenbook Prime UX32VD with i7-3517U CPU.

flannelhead · 2015-03-22 20:57:20

Now it seems that thermald runs just fine again and causes no problems with kernel 3.19.2. Marking this as solved.

Arch Linux

#1 2015-01-15 19:23:20

[Solved] Thermald and kernel 3.18.2 – CPU stalls

#2 2015-01-16 05:58:12

Re: [Solved] Thermald and kernel 3.18.2 – CPU stalls

#3 2015-01-16 16:55:59

Re: [Solved] Thermald and kernel 3.18.2 – CPU stalls

#4 2015-01-31 18:05:20

Re: [Solved] Thermald and kernel 3.18.2 – CPU stalls

#5 2015-03-22 20:57:20

Re: [Solved] Thermald and kernel 3.18.2 – CPU stalls

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