Configuration of the repository

Installing the repository

To install this repo, as a root user, enter the following command:

• Fedora 35: $ dnf copr enable ycollet/audinux
• Fedora 33, 34: $ dnf copr enable ycollet/linuxmao

To list all the package provided by this repo (you must enable the repo before):

$ dnf list --available | grep ycollet

To list the last 20 updated packages:

• Fedora 35: $ dnf repoquery --repoid=copr:copr.fedorainfracloud.org:ycollet:audinux --queryformat "%45{name} %{evr} %{buildtime}" | sort -r -k3 | head --lines=20
• Fedora 33, 34: $ dnf repoquery --repoid=ycollet-linuxmao --queryformat "%45{name} %{evr} %{buildtime}" | sort -r -k3 | head --lines=20

Installing the real time kernel

You can install the real time kernel. We will be able to select at boot time the real time kernel:

$ dnf install kernel-rt-mao

This command will install the last available RT kernel (the 5.11.4.rt11 as of today).

You can install some old kernel versions like 5.10.35.rt39:

$ dnf install kernel-rt-mao-5.10.35.rt39

Configuring the system

Before using the real time kernel, you need to fine tune /etc/security/limits.d/95-jack.conf. This file is installed by the jack-audio-connection-kit package. Under Fedora 34, you have the following content:

# Default limits for users of jack-audio-connection-kit

@jackuser - rtprio 70
@jackuser - memlock 4194304

@pulse-rt - rtprio 20
@pulse-rt - nice -20

You can add a “@jackuser - nice -20” line and comment all the @pulse-rt lines. Here is the result:

# Default limits for users of jack-audio-connection-kit

@jackuser - rtprio 90
@jackuser - memlock 4194304
@jackuser - nice -20

#@pulse-rt - rtprio 20
#@pulse-rt - nice -20

And then, add yourself to the jackuser group:

# as a root user
$ usermod -a -G jackuser <my_user_id>

And then log off from your session and log in again so that the changes can take effect.

With the latest kernel, there is a problem with AMD/Radeon graphic cards. This is a combination of problem between the kernel graphic driver and the xorg server. One way to wark around this problem is to deactivate the graphic acceleration layer of xorg. Add a file /etc/X11/xorg.conf.d/disable-gpu.conf with the following content:

Section "Extensions"
    Option "GLX" "Disable"
EndSection

The article “Configure Fedora to practice and compose music” talk a little bit more on this topic.