systemd-udevd high CPU usage

feiticeir0 · Posted: Tue Apr 22, 2014 10:36 pm Post subject: systemd-udevd high CPU usage

Hi all !

Recently i've started having a problem with systemd-udevd . I noticed my computer was getting slow. Even a small operation like alt+tab is slow...
Using TOP, i get this:

feiticeir0 · Posted: Wed Apr 23, 2014 8:25 am Post subject:

Well, I've dig a bit more and I think I've solved it, but a lit more usage is needed.

I've just upgrade (to a unstable version in portage) the nvidia drivers and apparently I don't have this problem anymore.

I'll wai and see !

Cheers

Bruno
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disperato · Tux's lil' helper Joined: 27 Apr 2004 Posts: 120

I'm having similar issues, on similar system. Let me explain.

starting from a few weeks ago, my computer start to hang with a frozen display (showing the last picture shown while working), frozen keyboard, frozen mouse.
I could not even use the ctrl+print (+S, +U, +B) sequence to safely reboot, had to rudely press the button, reboot with a key, fix partitions (need to avoid xfs corruption) and finally reboot.
The incident happened in various conditions, so could not say a specific program is the culprit. Didn't try ssh-ing to the laptop because hadn't time to configure it properly, nor the dmesg, rc.log and such were helpful in the slightest. The only thing clue I can tell, is I was using X (xfce4, precisely).

Hardware: intel+nvidia gfx 770m
Drivers: i915 from kernel; nvidia 334 from nvidia-drivers
Daemons: no bumblebee activated by default (I'm still getting used to it, so not using this so often, and *important* not using it when the freeze accidents happened. And have to say this is a very unfriendly way of using this infamous double cards hell, which highly discourage use of gpu, while keeping the intel video bus hot anyway: this fad is yet another stupid, idiotic way to engineer a system).

This nightmare stopped when I disabled the discrete GPU nvidia from BIOS. Obviously this is experimental, because it doesn't make sense having such a cpu and do not use it.
A few days after that (yesterday) I started using kernel from gentoo-sources-3.14.1. The problem had disappeared by disabling dGPU, and kept away using this new kernel, too.
I bet the solution was disabling dGPU.

Everything was going fine, up to a few minutes ago, when fans spiked up and 100% cpu was being used by a udev process as stated by "top". Top signalled that another udev process was running too, using a smaller and usual cpu percentage (around 3%). Had to restart udev to get rid of the offending udev task.
Checking console 0, I found the messages:

feiticeir0 · Posted: Wed Apr 23, 2014 9:37 am Post subject:

Hi disperato.

Thanks for the reply.

My laptop never hanged or crashed, just gets really really really slow... It's painful trying to work like that.

In my case, I can't deactivate the nvidia card on my BIOS - i don't have that option

Last night, after i posted this thread, i've updated the nvidia-drivers -( I have bumblebee working, but i don't use much the nvidia card - when i play games - rarely - I try the nvidia card, but is not very often.) and everything seemed OK - but only today i can tell for sure if that worked or not. If it's ok, I'll open a bug for that version of the nvidia-drivers.

Best regards

Bruno Santos
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feiticeir0 · Posted: Wed Apr 23, 2014 10:41 pm Post subject:

No... Still the same thing.... I'm really getting annoyed by this...

No clues whatsoever...
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feiticeir0 · Posted: Wed Apr 23, 2014 10:47 pm Post subject:

Well, if i stop bumblebee, the messages stop and systemd-udevd stops !

Is this a bumblebee bug ???
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disperato · Tux's lil' helper Joined: 27 Apr 2004 Posts: 120

I'm fighting (on a system never reformatted and constantly grown-updated-moved for 10 years or so, the time I've been a gentoo user) with the same beasts these days, nvidia-drivers (+xorg-server), bumblebee, and had one only incident with udevd behaving like your case, this is why I felt my case was similar. Now I'm realizing there is another difference, huge indeed, other than the difference between computer crashes and painfully slow marches: you have systemd-udevd, mine is openrc+udev

Intrigued by this fact I searched a bit on my system, just to discover that I don't have systemd installed and recalled that it is an alternative to the gentoo default openrc.
I have udevd, though, and only once had the slowing defect that is affecting your system. As for my issues, everything is working very fine (now, after much struggling, no more missed wake-up from sleep, no more errors from bumblebee, etc.).

Hence my question is: do you need systemd? Maybe systemd-udevd is fighting with udevd? May be that bumblebee is defaulting to use system-udevd that conflicts with udevd eating cpu/ram or filling some bus?

The answer to the first question is quick: if you are a >=gnome-3.8 user it's yes, otherwise can be discovered by:

feiticeir0 · Posted: Thu Apr 24, 2014 1:17 pm Post subject:

Hi disperato !

Well, that's right, i'm a Gnome 3 user. I just love it, but always considering others - when i have the time and patient to try them... I've used KDE, xfce, openbox, fluxbox, etc... I'm not settled yet !

I'll deepen the search for the cause of the problem and try to find out what is causing this... Bumblebee is a serious candidate . The funny thing is, it doesn't start right away, after the system boots... After an hour or so, i start noticing the slowness of the system and it's when i check top and see the systemd-udevd problem... and monitoring udev i start seeing those lines about the nvidia card...

I'll try and update bumblebee and see if it stops the problem...

Thanks for your replys.

Best regards

Bruno
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Royal_ts · n00b Joined: 23 May 2011 Posts: 44 Location: Leipzig

Hey!

Was you research successfully? I got the same problem and obviously udevd crashed because there is no db in

superpwnzormegaman · n00b Joined: 23 May 2014 Posts: 2

Hi

I had a similiar issue, I think i fixed it by changing the bumlbebeed.service file in

.maverick · Apprentice Joined: 29 Jan 2004 Posts: 159 Location: Bonn

The same happens to me, too. Did anyone find anything helpful, yet? This thread is about the only thing that comes up when looking for the symptoms ...

Bert Reynolds · n00b Joined: 19 Oct 2014 Posts: 1

I just had this too.

I fixed it by cleaning up the udev db.

Running: udevadm info -c

V3n3RiX · n00b Joined: 08 Nov 2014 Posts: 3

Well, after 1 day of hunting what causes the problem I think I found it. Indeed plugin-container from firefox causes the nvidia module to be loaded. None of the above solutions worked for me. I managed to find the way plugin-container loads the nvidia module : it uses nvidia-modprobe binary . So I took away executable permissions from it and now everything works : full hw accelerated flash, and udevd is calm.

Ant P. · Watchman Joined: 18 Apr 2009 Posts: 6920

ulenrich · Veteran Joined: 10 Oct 2010 Posts: 1483