JACK and nice values

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arifd
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JACK and nice values

Post by arifd »

I noticed that When JACK installs, it adds a configuration file for the audio group... and inside it (/etc/security/limits.d/audio.conf)

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@audio   -  nice      -19
this line is commented out. Does or does not the audio group not want to have the highest priority?

Also under

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ps -lu <username>
we can see jackdbus has a niceness of '0' doesn't it also want a high priority?
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LAM
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Re: JACK and nice values

Post by LAM »

I'm good with the default value aka i didn't uncomment that line.
But you are free to experiment, just remember what you changed in case you mess up. :D

in mix, nobody can hear your screen

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raboof
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Re: JACK and nice values

Post by raboof »

arifd wrote: Wed Jan 06, 2021 10:09 am I noticed that When JACK installs, it adds a configuration file for the audio group... and inside it (/etc/security/limits.d/audio.conf)

Code: Select all

@audio   -  nice      -19
this line is commented out. Does or does not the audio group not want to have the highest priority?
There are 2 mechanisms to prioritize processes relative to each other: 'rtprio' and 'nice'. 'rtprio' is 'strong', 'nice' is 'softer'. If allowed, Jack will use 'rtprio', and in that case it does not need 'nice' anymore.
arifd wrote: Wed Jan 06, 2021 10:09 am Also under

Code: Select all

ps -lu <username>
we can see jackdbus has a niceness of '0' doesn't it also want a high priority?
I haven't checked, but it is possible that jackdbus has multiple threads, and only the threads that are on the critical path have adjusted nice/rtprio values. You might need to play with the 'ps' parameters a bit to see those.
arifd
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Re: JACK and nice values

Post by arifd »

Intersting. Honestly, I figure the JACK gods know far better which tweaks to conduct, that I probably haven't stumbled on a linux performance goldmine!

Fingers crossed for Pipewire. If they do this right, it could be a game changer!!
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LAM
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Re: JACK and nice values

Post by LAM »

If you care about extreme performances don't look at Pipewire, at least for now. :lol:
viewtopic.php?f=27&t=22150&p=127127&hil ... re#p127127

in mix, nobody can hear your screen

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