Linux Lite Studio (1)
Low latency kernel
Hi, everyone!
I started this thread hoping that there are people here interested in audio production on Linux, specifically, on Linux Lite. I know there are targeted distros, but I am interested as said above, in a “Linux Lite Studio" flavor.
Thus, the title “Linux Lite Studio”.
Maybe they can help (or get help!).
Since the beginning is a kernel mattter, and then lots of specific applications, I suppose there are many here who can help find solutions and improvements.
From this perspective, a basic requirement is a lowlatency kernel.
Searching in Linux Lite’s kernel list (Lite Tweaks —>Kernel Install), I found only generic kernels.
Since nothing else is specified, the only alternative left, was Synaptic.
On a standard installation, the System Info App, reports “Linux 5.15.0.89-generic”.
So, I figured out I need to find its counter-part, “Linux 5.15.0.89-lowlatency”.
I found the kernel, installed it, and now (after reboot) is loaded.
The System Info App, reports “Linux 5.15.0.89-lowlatency”.
While in theory a “generic” kernel should be usable, in fact, there are specific settings at kernel level that need to be active, such as “threadirqs”.
While this is relative simple to solve, for the “-generic” kernel, there are specific settings that are unavailable in this type of kernel. That makes things go sideways when speaking of latency and DSP (Digital Signal Processing) long chains: DAW setup, many tracks, many plugins.
In order to make JACK work properly, I ndeed to have those kernel options.
Here is a common message issued by JACK:
“Cannot create RT messagebuffer thread: Operation not permitted (1)”.
There are others also.
Although JACK runs, the problem is that I got xruns (frame droppings) with the “-generic” kernel.
Main problem here, is the latency. Since latency is a huge story, I’ll skip the details and say that each and every piece of “something”, where “something” means both hardware and software, has a specific latency. The bad thing is that this is additive so the longer the DSP chain, the greater the lateny hence, the more xruns.
The lower the latency, the better are the results in the audio process (recording, playing, mastering).
The kernel options needed, i.e., are the following:
CONFIG_HAVE_LATENCYTOP_SUPPORT=y
CONFIG_LATENCYTOP=y
This is possible only with the said type of kernel.
Those settings, are needed to use a latency monitoring tool, called “LatencyTOP”, which is very similar with “Top” and “Htop”, except it is specifically designed for pro-audio use.
