Docker on CentOS 7.2: kernel:unregister_netdevice: waiting for lo to become free. Usage count = 1

Question

I'm running Docker on CentOS 7, from time to time there's the following message displayed:

Message from syslogd@dev-master at Mar 29 17:23:03 ...
  kernel:unregister_netdevice: waiting for lo to become free. Usage count = 1

I've googled a lot, read a lot of resources found and tried many ways like keeping my system updated, upgrading kernel etc, but the message still keeps showing up, it's not too often but sooner or later I'll see it. Also I found issue for this problem on docker github is still open, then my questions are:

1. What does this message mean? Could somebody give me a simple explanation why docker causes it?
2. Is there any workaround for this?
3. If it could not be fixed yet(the issue is still open), will it affect the server or services running inside docker container? Will it be a serious performance issue because it also happens on our production servers?

Docker version:

Client:
 Version:      1.11.1
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   5604cbe
 Built:        Wed Apr 27 00:34:42 2016
 OS/Arch:      linux/amd64

Server:
 Version:      1.11.1
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   5604cbe
 Built:        Wed Apr 27 00:34:42 2016
 OS/Arch:      linux/amd64

OS info:

CentOS 7, with kernel version: 4.6.0-1.el7.elrepo.x86_64

I really appreciate for any info/tips or resources, thanks a lot.

Solution

Your best source of information is the issue you linked to docker#5618. This is a kernel bug, and has not yet been resolved. The issue is "triggered" by docker because starting/stopping containers also creates network interfaces for containers when they are created/destroyed.

Comments

[shizhz]

Thanks for your info, could you please give some info for my 3rd question?

[thaJeztah]

Difficult to tell; it really depends on your situation. Some people never run into the issue, some do.

[jeremy.mooer]

Quick suggestion. Each line of your docker file (say your executing RUN 10 times in a row) will create an intermediary docker image. If you are able, you could combine some of them -- e.g., if you have 2 RUNs together, then && them together (again -- if it makes sense).