Realtime Kernel

Questions about applications and software
Forum rules
Before you post please read how to get help
Post Reply
buscon
Level 1
Level 1
Posts: 35
Joined: Tue Sep 19, 2017 4:27 pm

Realtime Kernel

Post by buscon »

hi all,

I would like to install a realtime kernel, as I work on audio application that needs fast (low latency) capabilities.
So far I have been using the lowlatency kernel with ok results, still I experience xruns and realtime kernels should help with that.

I was not able to find proper information about it, maybe someone can point me in the right direction?
I hope I do not have to compile the kernel for that :)
User avatar
Kadaitcha Man
Level 11
Level 11
Posts: 3605
Joined: Mon Aug 27, 2012 10:17 pm

Re: Realtime Kernel

Post by Kadaitcha Man »

buscon wrote:
Wed Feb 26, 2020 9:41 am
I was not able to find proper information about it
Define 'proper information'.
Coming to a thread near you: Lots of bragging about my AMD 5950X. Currently delayed due to high demand.
It's pronounced kad-eye-cha, not kada-itcha.
buscon
Level 1
Level 1
Posts: 35
Joined: Tue Sep 19, 2017 4:27 pm

Re: Realtime Kernel

Post by buscon »

Kadaitcha Man wrote:
Wed Feb 26, 2020 4:07 pm
buscon wrote:
Wed Feb 26, 2020 9:41 am
I was not able to find proper information about it
Define 'proper information'.
Proper information about how to install it from a repository for Ubuntu 18.04.
It seems like to Ubuntu/Debian repository offers such a kernel.
User avatar
JoeFootball
Level 9
Level 9
Posts: 2917
Joined: Tue Nov 24, 2009 1:52 pm
Location: /home/usa/mn/minneapolis/joe

Re: Realtime Kernel

Post by JoeFootball »

buscon wrote: Proper information about how to install it from a repository for Ubuntu 18.04.
It seems like to Ubuntu/Debian repository offers such a kernel.
"Early on in Linux audio production, Real-Time kernels were the only way to get low- and no-latency audio for professional audio applications. However, since Linux 2.6, the real-time stack has been part of the Linux kernel, having a kernel patched with a real-time stack is no longer necessary."

Ubuntu source: https://help.ubuntu.com/community/Ubunt ... TimeKernel
User avatar
MrEen
Level 22
Level 22
Posts: 15169
Joined: Mon Jun 12, 2017 8:39 pm

Re: Realtime Kernel

Post by MrEen »

Hi buscon.

You might want to peruse through this thread on LinuxMusicians and give some consideration to the Liquorix kernel as mentioned in this post. This is a very new kernel, so if your system is quite old, it may not be a good fit for you. The poster that mentions it is using a system that is over 5 years old, so anything newer than that should be fine.

There are also plenty of good nuggets in that thread, and you might want to join that forum as well if you haven't already.
buscon
Level 1
Level 1
Posts: 35
Joined: Tue Sep 19, 2017 4:27 pm

Re: Realtime Kernel

Post by buscon »

JoeFootball wrote:
Wed Feb 26, 2020 5:28 pm
buscon wrote: Proper information about how to install it from a repository for Ubuntu 18.04.
It seems like to Ubuntu/Debian repository offers such a kernel.
"Early on in Linux audio production, Real-Time kernels were the only way to get low- and no-latency audio for professional audio applications. However, since Linux 2.6, the real-time stack has been part of the Linux kernel, having a kernel patched with a real-time stack is no longer necessary."

Ubuntu source: https://help.ubuntu.com/community/Ubunt ... TimeKernel
this is generally true, but for having real time audio applications, real time still better than lowlatency.
buscon
Level 1
Level 1
Posts: 35
Joined: Tue Sep 19, 2017 4:27 pm

Re: Realtime Kernel

Post by buscon »

MrEen wrote:
Wed Feb 26, 2020 5:29 pm
Hi buscon.

You might want to peruse through this thread on LinuxMusicians and give some consideration to the Liquorix kernel as mentioned in this post. This is a very new kernel, so if your system is quite old, it may not be a good fit for you. The poster that mentions it is using a system that is over 5 years old, so anything newer than that should be fine.

There are also plenty of good nuggets in that thread, and you might want to join that forum as well if you haven't already.
Thanks a lot for posting such thread. the Liquorix kernel should work on my machine too, I will try it out.
User avatar
Pjotr
Level 22
Level 22
Posts: 15911
Joined: Mon Mar 07, 2011 10:18 am
Location: The Netherlands (Holland)
Contact:

Re: Realtime Kernel

Post by Pjotr »

You might benefit from the easy control over specialized kernels provided by the Linux Mint tools from gm10:
https://launchpad.net/~gm10/+archive/ub ... mint-tools

I've used his kernel tool yesterday to install a Mainline kernel on the computer of someone who (unfortunately) needed it. Note that you need to enable access to Mainline and specialized kernels first in the Preferences section of his Update Manager (tab Expert).
Tip: 10 things to do after installing Linux Mint 20 Ulyana
Keep your Linux Mint healthy: Avoid these 10 fatal mistakes
Twitter: twitter.com/easylinuxtips
All in all, horse sense simply makes sense.
Hoser Rob
Level 16
Level 16
Posts: 6826
Joined: Sat Dec 15, 2012 8:57 am

Re: Realtime Kernel

Post by Hoser Rob »

JoeFootball wrote:
Wed Feb 26, 2020 5:28 pm
buscon wrote: Proper information about how to install it from a repository for Ubuntu 18.04.
It seems like to Ubuntu/Debian repository offers such a kernel.
"Early on in Linux audio production, Real-Time kernels were the only way to get low- and no-latency audio for professional audio applications. However, since Linux 2.6, the real-time stack has been part of the Linux kernel, having a kernel patched with a real-time stack is no longer necessary."

Ubuntu source: https://help.ubuntu.com/community/Ubunt ... TimeKernel
I've suspected this myself, thx for some confirmation. It's like all those users trying to get all their hardware decoding options for their video players going when hardware decoding for video file playback hasn't been necessary for 15 to 20 years. The mpv devs even recommend turning it off because of reliability issues with some codecs. This seems similar to me.
User avatar
trytip
Level 13
Level 13
Posts: 4927
Joined: Tue Jul 05, 2016 1:20 pm

Re: Realtime Kernel

Post by trytip »

the only realtime you need is ulimit -r -l what do have for this in terminal?
mint03@mint03:~$ ulimit -r -l
real-time priority (-r) 99
max locked memory (kbytes, -l) unlimited

mint03@mint03:~$
Image
buscon
Level 1
Level 1
Posts: 35
Joined: Tue Sep 19, 2017 4:27 pm

Re: Realtime Kernel

Post by buscon »

trytip wrote:
Thu Feb 27, 2020 9:45 am
the only realtime you need is ulimit -r -l what do have for this in terminal?
mint03@mint03:~$ ulimit -r -l
real-time priority (-r) 99
max locked memory (kbytes, -l) unlimited

mint03@mint03:~$
Thanks for the information and yes, I set already these values on my computer, so it is already correct.

In the meanwhile I found out two relevant things:
  • using an external screen (through the USB-C port) increases the xruns
  • one of the USB plug of my computer seems not able to handle the sound card
Post Reply

Return to “Software & Applications”