Bug 1544096

Summary: msg="Your kernel does not support cgroup rt runtime"
Product: [Fedora] Fedora Reporter: Pierre Juhen <pierre.juhen>
Component: dockerAssignee: Daniel Walsh <dwalsh>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 27CC: adimania, admiller, amurdaca, dwalsh, fkluknav, ichavero, jcajka, lsm5, marianne, nalin, santiago, vbatts
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Hardware: x86_64   
OS: Linux   
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Last Closed: 2018-02-11 15:24:16 UTC Type: Bug
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Description Pierre Juhen 2018-02-10 09:15:54 UTC 
Description of problem:

docker shows messages 
msg="Your kernel does not support cgroup rt runtime" 
at startup

Version-Release number of selected component (if applicable):

1.13.1-44.git584d391.fc27

is not present in version 

docker-1.13.1-26.gitb5e3294.fc27.x86_64

How reproducible:
Always
Comment 1 Daniel Walsh 2018-02-11 10:58:43 UTC 
Not sure what you are reporting.

docker-1.13.1-44.git584d391.fc27 seems to be current in Fedora 27. Does this have support for the cgroup rt runtime?
Comment 2 Pierre Juhen 2018-02-11 14:52:03 UTC 
In latest release, when docker starts, if you do a :

systemctl status docker, 

there is a warning :

msg="Your kernel does not support cgroup rt runtime" 

This is not the case with previous version : 

docker-1.13.1-26.gitb5e3294.fc27.x86_64

with the same kernel.

This seems to be a regression in docker (I did a downgrade of docker, it solves this "issue").

Regards,
Comment 3 Antonio Murdaca 2018-02-11 15:14:50 UTC 
This is not an issue. Very likely we back ported RT-kernel feature and that's just saying that your kernel doesn't support Real Time features. The warning is innocuous