sudo dnf install jack-audio-connection-kit-dbus qjackctl rtirq realTimeConfigQuickScan
sudo usermod -a -G audio,jackuser,users `whoami`
$ cat /etc/security/limits.d/95-jack.conf:
@jackuser - rtprio 90
@jackuser - nice -19
@jackuser - memlock 209715200
$ cat /etc/udev/rules.d/40-timer-permissions.rules
KERNEL=="rtc0", GROUP="audio"
KERNEL=="hpet", GROUP="audio"
Check system settings for audio performance (be careful https://bugzilla.redhat.com/show_bug.cgi?id=1541399):
$ SOUND_CARD_IRQ=23 realTimeConfigQuickScan
== GUI-enabled checks ==
Checking if you are root... no - good
Checking filesystem 'noatime' parameter... found - warning
/ does not have the 'noatime' parameter set
/boot does not have the 'noatime' parameter set
/home does not have the 'noatime' parameter set
For more information, see http://wiki.linuxmusicians.com/doku.php?id=system_configuration#filesystems
Checking CPU Governors... CPU 0: 'performance' CPU 1: 'performance' CPU 2: 'performance' CPU 3: 'performance' - good
Checking swappiness... 10 - good
Checking for resource-intensive background processes... none found - good
Checking checking sysctl inotify max_user_watches... >= 524288 - good
Checking access to the high precision event timer... readable - good
Checking access to the real-time clock... readable - good
Checking whether you're in the 'audio' group... yes - good
Checking for multiple 'audio' groups... no - good
yes - good.
Checking the ability to prioritize processes with chrt... yes - good
Checking kernel support for high resolution timers... found - good
Kernel with Real-Time Preemption... not found - not good
Kernel without real-time capabilities found
For more information, see http://wiki.linuxmusicians.com/doku.php?id=system_configuration#installing_a_real-time_kernel
Checking if kernel system timer is set to 1000 hz... found - good
Checking kernel support for tickless timer... found - good
== Other checks ==
Checking filesystem types... ok.
ok.
Run jackd:
sudo cpupower frequency-set -g performance
pasuspender qjackctl
After mixxx start:
sudo renice -10 -p `pidof jackd` && sudo renice -10 -p `pidof mixxx`