After configuring debian ardour still running at normal priotity

Hi
I configured my debian system as per @x42 instructions in the topic Debian 12 configuration

It seems to be running ok, though not supercharged
System monitor shows it to be running with Normal priority
image
How should I investigate this?
Many thanks

That looks like nice level; you need to check realtime priority.
This is from htop output, for example:
image

I don’t remember the best tool for displaying the RT priorities from CLI. I think ps with -l to show long listing, pri will be realtime priority, and ni will be the standard nice level.

Thanks Chris
Heres what i get from htop

ps -l
image

Does this look right?

I have got
@audio rtprio 95
in /etc/security/limits.conf
so I thought that the realtime priority would be 95
Have I misunderstood?

That is the limit, the actual value will be configured somewhere.
Are you using Pipewire? I think that defaults to using priority 80 by default, so seeing Ardour threads with priority of 79 and 81 seems right.

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Yes, PRI -81 … -70 looks right. You could confiugre htop to also show thread policy…

Using htop, I notice that only one of my Ardour 8.12 pids is running with priority -81. the other ardour pids though are running with priority 20. is this optimal and if not, any thoughts on most efficient way to fix this?

limits.conf shows:
@audio - memlock unlimited
@audio - rtprio 90

running ubuntu studio 24.04

as a possible fix, i found:
sh

sudo renice 0 -p <pid>

but not sure this is correct…

Yeah, you do not want your graphical interface threads running with high realtime priority, it will interfere with the audio processing.

You should not use sudo to change the priority of a process that you started under your user account, and nice does not apply to realtime processes.

Stop trying to “fix” things which are not broken and go make some music.

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lol.

this is how i learn in my off time… which i do when i am not recording or writing.

Thanks for your helpful explanation. Im using alsa for ardour, though pipewire is part of Debian Trixie and it runs anyway.
Do I need to stop Pipewire? Would it improve anything?

Thanks Robin
I dont know what thread policy is and Its not listed in the manpage.
Would it be an important thing to show in this case?

I think you may have read too quickly… I asked if this is “optimal” or does something need fixing?

Binary question…

Clearly other people have questions about the same thing…

Not really.

Ardour will be talking directly to ALSA and the specific audio device it’s using will, effectively, have been removed as far as other applications are concerned, including Pipewire.

Pipewire will continue to run in parallel and, if you have another audio interface (such as onboard audio or HDMI) it will probably try to use it. And if it does, you may get audio from other desktop applications, but not through the audio device that Ardour is using.

The Pipewire daemon will consume more CPU cycles, obviously, but unless it’s handling other audio applications, not enough to worry about.

It certainly shouldn’t impact on what Ardour is doing in any way.

Cheers,

Keith

Many thanks for this Keith

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