Arch Linux

0.6.2
rtstatus: corrected bug showing error when no internal audio cards
rtmonitorirq: usage has changed, now you can simply call rtmonitorirq without parameter.

0.6.2
added for convenience some .desktop files for launching the scripts

0.6.1
RTMONITORIRQ
Now supports whatever number of processor cores
RTAPP
added manualdec option
manualdec: same as manual but the priority will decrease by one step from the first to the last application

0.6
Now rtstatus is more complete.
Added rtcheck, rttest, rtmonitorirq

RTMONITORIRQ

For checking the realtime utilization you can start rtmonitorirq.
Usage: rtmonitorirq <irq>
Example: rtmonitorirq 23
This will show the name of devices connected to the specified irq and the IRQs/Second parameter.
If the same irq of an audio device is used by another device you will see that IRQs/Second will be > 0 also when the audio card is disconnected.

RTTEST

rttest will show the latency of your system using first only with cyclictest (STANDARD TEST) and after with both hackbench and cyclictest (STRESS TEST). The package rt-tests is a dependency.
If the results of STANDARD TEST are much higher than the results of STRESS TEST and you have an Intel processor you could add a line like
intel_idle.max_cstate=0
to your Grub or Syslinux kernel line in configuration file.

RTCHECK

rtcheck will show some important information about your system:
1) Type of kernel (realtime or not)
2) rtc0 and hpet max user frequency
3) CPU scaling status
4) System latency
5) Audio group members
6) pam-limits
7) Realtime max priority and max memory allocation

0.5.2
Added rtmonitoriq (you must install itop or itop-git)
Now rtstatus should show audio cards addresses and names when there are multiple internal or firewire cards installed.
Little improvements on bash code.

0.5.1
Little improvments on bash code.

Before running rtapp, have a look at the config file located
at /etc/rtapp/rtapp.conf and make sure the defaults
are OK.

--------------------------------

For the variables RTIRQ_PRIO_DECR, RTIRQ_PRIO_HIGH, RTIRQ_PRIO_DECR, RTIRQ_NAME_LIST see rtirq documentation.

# Here you can list the applications that you want give realtime priority
# jack and jackdbus shoud not be included in this list.
APPLICATIONS="mpd hqplayer hqplayerd mediacenter20 networkaudiod deadbeef"

# Maximum value MAX_PRIORITY for application priority. This must be (RTIRQ_PRIO_DECR + 1) < MAX_PRIORITY <= (RTIRQ_PRIO_HIGH - (RTIRQ_PRIO_DECR * <number of items in RTIRQ_NAME_LIST>))
MAX_PRIORITY="80"

# manual: the applications priority will have the value set in MAX_PRIORITY
# auto: the value will be a step (RTIRQ_PRIO_DECR) under the minimum value of priority set by rtirq (this value depends on the number of items in RTIRQ_NAME_LIST and the number of audio hardware connected to the same USB bus)
# autodec: same as auto but the priority will decrease by one step from the first to the last application
MODE="auto"

-------------------------------

To start rtapp, you must first start the systemctl timer:
# systemctl start rtapp.timer

Then you can enable the service at boot:
# systemctl enable rtapp.timer

rtapp.timer will call rtapp.service in /usr/lib/systemd/system

rtapp will check the priority of audio applications every 60 seconds.
If you wanto to change this please edit OnUnitActiveSec in /usr/lib/systemd/system/rtapp.timer

RTRESET

rtreset will reset all real time priority (irq and applications) to SCHED_OTHER

RTSTATUS

rtstatus will show the status of irq and applications realtime priorities.
It is also very useful for checking if your audio card is sharing IRQ with another device since it is showing the Vendor and Product names!
(cat /proc/interrupts instead will be useless because it will not show cards names)