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Tags: 16.04   mount   debug  
Link: πŸ” See Original Answer on Ask Ubuntu πŸ”—

URL: https://askubuntu.com/q/848237
Title: How do I get rid of /sys/kernel/debug/tracing?
ID: /2016/11/11/How-do-I-get-rid-of-_sys_kernel_debug_tracing_
Created: November 11, 2016    Edited:  June 12, 2020
Upload: November 24, 2022    Layout:  post
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At first I thought the problem had something to do with your Linux net-services revealed by uname -a command. I’m on Ubuntu 16.04 desktop so had little hope I could solve these two questions. I read up on the situation from this link: (redhat.com - Realtime Tuning Guide) that discusses /sys/kernel/debug/tracing/

Question 1: How did β€œdebugfs on /sys/kernel/debug” get mounted?

Imagine my surprise learning on my system kernel tracing was also enabled:

# cat /proc/sys/kernel/ftrace_enabled
1

Also when I type mount, this is one of the lines that appears:

debugfs on /sys/kernel/debug type debugfs (rw,relatime)

I rebooted my kernel 4.4.0-47 to 4.4.0-45 then to 4.8.5 and finally to 3.13.0-92. ALL these versions have /sys/kernel/debug mounted.

To answer your question (paraphrased) β€œhow did this happen?” -> it happens to everyone.

Question 2: How do I get rid of it?

To answer your question β€œhow do I get rid of it?”, use:

sudo umount debugfs

Note this only works for current session.

Summary Thoughts

Even though trace is enabled on all Ubuntu kernel versions I’ve tested, it is not activated until you tell it to start monitoring a specific event. After an event is activated then it will slow down your CPU.

Basically I would not worry about this…

⇧ Intel SkyLake Blank Screen on Ubuntu 16.10 Cut or limit internet connection to other wifi devices  β‡©