I realise this may be considered a form of heresy, but I am attempting to get jack running with a dummy backend on Ubuntu 18.04 under windows subsystem for linux 2 (WSL2). Remarkably this does actually work. However, only if I execute jack as root (i.e. using sudo) can it obtain permissions for real-time scheduling, which is not ideal.
I think I have all the normal Ubuntu settings in place but don’t know what differences might exist between normal Ubuntu and the version that exists with WSL2.
The output of running realtimeconfigquickscan is pasted below, Does anyone have any pointers of where to look?
P.S. Apologies if this or something like it has been discussed before. Is there a way to search the archives of this list that I am missing?
$ perl ./realTimeConfigQuickScan.pl
== GUI-enabled checks ==
Checking if you are root... no - good
Checking filesystem 'noatime' parameter... 4.19.104 kernel - good
(relatime is default since 2.6.30)
cat: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu4/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu5/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu6/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu7/cpufreq/scaling_governor: No such file or directory
Checking CPU Governors... CPU 0: '' CPU 1: '' CPU 2: '' CPU 3: '' CPU 4: '' CPU 5: '' CPU 6: '' CPU 7: '' - not good
Set CPU Governors to 'performance' with 'cpupower frequency-set -g performance' or 'cpufreq-set -c <cpunr> -g performance' (Debian/Ubuntu)
See also: http://linuxmusicians.com/viewtopic.php?f=27&t=844
Checking swappiness... 60 - not good
** vm.swappiness is larger than 10
Set swappiness by adding 'vm.swappiness=10' to /etc/sysctl.conf and rebooting
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... not found - not good
/dev/hpet not found.
Checking access to the real-time clock... not found - not good
/dev/rtc not found (perhaps create a symlink?).
Checking whether you're in the 'audio' group... yes - good
Checking for multiple 'audio' groups... no - good
chrt: failed to set pid 0's policy: Operation not permitted
Checking the ability to prioritize processes with chrt... no - not good
Could not assign a 80 rtprio SCHED_FIFO value. Set up limits.conf.
For more information, see http://wiki.linuxaudio.org/wiki/system_configuration#limitsconfaudioconf
Checking kernel support for high resolution timers... found - good
Kernel with Real-Time Preemption... not found - not good
Kernel without 'threadirqs' parameter or real-time capabilities found
For more information, see https://wiki.linuxaudio.org/wiki/system_configuration#do_i_really_need_a_re…
Checking if kernel system timer is high-resolution... found - good
Checking kernel support for tickless timer... found - good
== Other checks ==
Checking filesystem types... ok.
** Set $SOUND_CARD_IRQ to the IRQ of your soundcard to enable more checks.
Find your sound card's IRQ by looking at '/proc/interrupts' and lspci.
The FFADO project announces the availability of FFADO version 2.4.4.
This is a non-critical update. The only change since version 2.4.3 is the
disabling of the optional device registration dialog. The data gathered is
of peripheral value these days, making its ongoing collection unnecessary.
FFADO version 2.4.4 is available as a tarball:
Formal release notes are at
(on behalf of the FFADO project)