Arch Linux

Moosbart

Member

Registered: 2013-06-19

Posts: 14

I don't get NMI watchdog disabled

from what i read in the forums it makes me think i don't need/want watchdog running on my laptop. However, it seems i cannot disable it. dmesg and top show me some watchdog things are running:

$ dmesg | grep watchdog
[    0.110010] NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter.

and

$ top -bn1 | grep watchdog
   12 root      20   0       0      0      0 R   0.0  0.0   0:00.00 watchdog/0
   13 root      20   0       0      0      0 R   0.0  0.0   0:00.00 watchdog/1

i created a file:

$ cat /etc/sysctl.d/disable_watchdog.conf
kernel.nmi_watchdog = 0

dmesg still shows the above output. although when i put "nmi_watchdog = 0" in the kernel line the dmesg output is gone, but still there are the two processes shown by top.

a second file blacklist two modules which i thought were responsible for starting watchdog. they dont get loaded anymore but still watchdog runs

$ cat /etc/modprobe.d/watchdog.conf 
blacklist iTCO_wdt 
blacklist iTCO_vendor_support

is there anything else i could try?

bohoomil

Member

Registered: 2010-09-04

Posts: 2,376

Website

Re: I don't get NMI watchdog disabled

Put this

# Turn OFF NMI watchdog
kernel.nmi_watchdog = 0

to your /etc/sysctl.conf and reboot your computer.

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Moosbart

Member

Registered: 2013-06-19

Posts: 14

Re: I don't get NMI watchdog disabled

thank you for the reply, unfortunately it doesn't help. dmesg and top still report watchdog enabled and running.

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: I don't get NMI watchdog disabled

Can you check the actual contents of /proc/sys/kernel/nmi_watchdog?  Is it the zero you are trying to make it?

Moosbart

Member

Registered: 2013-06-19

Posts: 14

Re: I don't get NMI watchdog disabled

yes it is zero. there are two other files: /proc/sys/kernel/watchdog and /proc/sys/kernel/watchdog_thresh containing 0 and 10, respectively.

jrussell

Member

From: Cape Town, South Africa

Registered: 2012-08-16

Posts: 510

Re: I don't get NMI watchdog disabled

Isn't there a difference between the hardware watchdog and the software watchdog? Which thread did you read that makes you think you don't need watchdog?
I see there is https://www.archlinux.org/packages/extr … /watchdog/ in the repos, and its not insatlled on my system but I have:

jason-laptop% dmesg | grep watch
[    0.103290] NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter

I think you read somewhere that you don't need the software watchdog https://www.archlinux.org/packages/extr … /watchdog/ as apposed to the watchdog you are trying to disable. I also read a thread discussing software watchdog on arch, cant find it though.

Last edited by jrussell (2013-06-26 15:41:08)

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WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: I don't get NMI watchdog disabled

@jrussell, the HW watchdog consumes power, and is very rarely used on desktop/laptops.  It is much more common to find amongst embedded machines and servers.  So disabling it for your laptop is particularly sane because it is reducing power consumption from a function you probably aren't using anyway.

jrussell

Member

From: Cape Town, South Africa

Registered: 2012-08-16

Posts: 510

Re: I don't get NMI watchdog disabled

@jrussell, the HW watchdog consumes power, and is very rarely used on desktop/laptops.  It is much more common to find amongst embedded machines and servers.  So disabling it for your laptop is particularly sane because it is reducing power consumption from a function you probably aren't using anyway.

I see, so the HW watchdog is enabled by default on arch then from what I can tell?

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WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: I don't get NMI watchdog disabled

I see, so the HW watchdog is enabled by default on arch then from what I can tell?

Typically, you can just set /proc/sys/kernel/watchdog to zero, and it should be done with.  I'm not sure why this is not working for the OP.

@OP, can you set kernel.watchdog=0 as well and then test?

Last edited by WonderWoofy (2013-06-26 15:54:45)

Moosbart

Member

Registered: 2013-06-19

Posts: 14

Re: I don't get NMI watchdog disabled

@OP, can you set kernel.watchdog=0 as well and then test?

it doesn't change any. am confused now about the hardware and software watchdog. not sure which one i want to disable. lol.
my aim was: less processes running, less power consumption, turn off the reboot functionality when cpu hangs.

Last edited by Moosbart (2013-06-26 16:02:43)

jrussell

Member

From: Cape Town, South Africa

Registered: 2012-08-16

Posts: 510

Re: I don't get NMI watchdog disabled

@OP, can you set kernel.watchdog=0 as well and then test?

it doesn't change any. am confused now about the hardware and software watchdog. not sure which one i want to disable. lol.

haha sorry you dont have the software watchdog be default unless you installed it as far as I know, you are dealing with the hardware watchdog I think.

You can see if the software watchdog is installed with

pacman -Q watchdog

It probably isnt installed

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Moosbart

Member

Registered: 2013-06-19

Posts: 14

Re: I don't get NMI watchdog disabled

ok, thanks, it seems not installed. query returns: error: package 'watchdog' was not found

Moosbart

Member

Registered: 2013-06-19

Posts: 14

Re: I don't get NMI watchdog disabled

just for the record, where i read about: For Notebook users watchdogs are useless

panth0r

Member

Registered: 2012-08-14

Posts: 6

Re: I don't get NMI watchdog disabled

Moosbart: have you found a solution or does anybody have more suggestions?

Thanks!