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Questions tagged [realtime]

Related to the use of Ubuntu as a real-time OS, whether through use of a patch, replacement kernel or other method. This is often desired in the context of industries such as automation and CNC machines, as well as certain audio applications. Questions may relate to specific real-time patches/kernels, integrating those patches/kernels on an Ubuntu system, or using an RT Ubuntu system in a given application.

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Real time kernel for Nvidia and WSL2

I am trying to set up a real time kernel (Preempt_RT) for a Franka Emika robot. My computer is running on Nvidia, and I have read that Nvidia and Linux RT don't go together. In addition, I am using ...
bot24's user avatar
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1 vote
1 answer
138 views

Debugging RCU stalls on Ubuntu Server 22.04, 5.15-realtime

I am trying to isolate CPUs on an AMD EPYC 8534PN (64C/128T). Unfortunately, I see the RCU stalls and the server crashes over and over. And I am not really sure what I am doing wrong. The crashes only ...
ninjab3s's user avatar
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39 views

GRUB: Boot generic kernel instead of realtime ONLY on next boot

I've been looking all over for this, it must be possible but the closest answer i could find is this one: How can I get grub2 to boot a different option only on the next boot? This is for a laptop ...
dolt's user avatar
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1 answer
285 views

Lost Wifi adapter after real-time kernel update - Need help fixing drivers?

I am working on a Dell Precision 5770 laptop which has Ubuntu Jammy 20.04.3. I was able to install the realtime kernel using ubuntu pro sudo pro enable realtime-kernel and it worked fine. However, ...
rodnram's user avatar
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215 views

5.15.0-1051-realtime kernel release notes

On my 22.04.3 LTE machine I have upgraded the kernel from 5.15.0-1050-realtime to 5.15.0-1051-realtime. Where could find I a document summarizing the fixes and changes between two subsequent kernel ...
Andrew Sergeev's user avatar
1 vote
1 answer
65 views

Realtime kernel on webserver with MySQL

Enabling realtime kernel will it increase the performance on Apache and MySQL webserver?
ind's user avatar
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How do I upgrade to RealTime kernel with a ZFS hardrive?

I have enabled the realtime kernel, but when booting I fail to load the ZFS modules. As a result, I drop into a BusyBox shell. Is there a way to fix this in Ubuntu 22? ` 22.04.1-Ubuntu SMP ...
Chris's user avatar
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1 answer
378 views

Tuned-admin profile realtime does not work for ubuntu 20.04

I would isolate cores using tuned realtime profile. I have modfiled /etc/tuned/realtime-variables.conf # Examples: isolated_cores=0-7 # # # Uncomment the 'isolate_managed_irq=Y' bellow if you want ...
Wei Qiu's user avatar
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1 answer
1k views

Installing PREEMPT_RT kernel on ubuntu 20.04.5 LTS (focal)

I am trying to install a real kernel that I need for an application (controlling a UR robot) and I followed the UR driver tutorial on git hub on how to install it. First I ran the command: $ uname -r ...
Hamzalihi's user avatar
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990 views

How do I install custom (real-time) Linux kernel headers?

Some background I've successfully patched a Linux kernel with the PREEMPT_RT patch, configured it, built it, and booted from it. The steps I took: Patched kernel 5.4.230 with PREEMPT_RT # Get kernel ...
branchwithlink's user avatar
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2 answers
2k views

How do I fully remove the Realtime Kernel?

I'm having an issue uninstalling the Realtime Kernel. I sort of installed it as I misunderstood what it actually is (I confused it with livepatching). I've followed this guide and managed to "...
Matthieu B's user avatar
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1 answer
828 views

Is Ubuntu Core 22.04.1 Real Time not avaliable for personal use?

I've recently deployed the Ubuntu Core 22 Real time OS into a raspberry pi 4 in order to deploy an application using the real time feature they announced recently. When I run $uname -a I can not see ...
Domenec's user avatar
1 vote
0 answers
220 views

Trigger PipeWire To Conect Application to Application

When I launch an application (e.g. firefox or chrome) I just want to automatically connect that application to an ardour input and nothing else. Instead whenever I launch firefox, for example, it ...
physiii's user avatar
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225 views

Significant process slow down when the CPU is under increased work load

I am testing the communication latency between a microcontroller(teensy4.1) and my desktop computer (ubuntu 20.04.3 with 5.15 kernel patched with PREEMPT-RT) The microcontroller is directly connected ...
KWang's user avatar
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1 vote
1 answer
710 views

Unable to boot RT kernel at grub advance option after RT patch installation

I have successfully installed the rt patch follow the guide from Installing real time patch for Ubuntu 20.04 . At the grub boot option, I am able to see the 5.19-generic and 5.19-rt options. when I ...
michaeldylann's user avatar
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1 answer
80 views

Ubuntu LTS Desktop - How can I configure complete synchronisation between two desktop computers. Applications, Settings, Files and folders?

I need to set a realtime synchronisation between 2 or 3 Ubuntu LTS Desktops. All applications, all files and folders, all setting, all changes in a real time. And if somebody, makes changes of one of ...
Vladimir Dimitrov's user avatar
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45 views

Installation Ubuntu server on top of an existing one

Actually I'm developing a web application using PHP and realtime Chat application and notications using NodeJs. In a Local network There is an ubuntu server to connect some windows machines to make a ...
Aisthesis Cronos's user avatar
0 votes
1 answer
12k views

Installing real time patch for Ubuntu 20.04

I am trying to install Real time patch on ubuntu 20.04 I followed many steps and for each trial it took about 4 hours to complete. Unfortunately none of these trials worked (in the links below). I ...
Ibraheem's user avatar
3 votes
2 answers
329 views

Capture script output to add datetime to ouput in realtime

I'm looking to capture the output of a shell script execution in real time to enrich it with information giving the date and time. To illustrate, I have for example a script of this type that I must ...
Thomas W's user avatar
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0 answers
326 views

What are the risks to update 18.04.5 kernel (5.4.0-74) to the latest 5.4.125 to match the PREEMP_RT patch?

Good day everyone! I see that uname -r returns 5.4.0-74 in my 18.04.5 I don't see any version like this at kernel.org. Why the dash? I hear that Ubuntu makes changes to their kernel. This suggests ...
keith bradley's user avatar
1 vote
1 answer
1k views

Ubuntu 20.04 setting PREEMPT_RT - Loading initial ramdisk

I am trying to update the kernel of Ubuntu from 5.8.0-50-generic to 5.9.1-rt20 (because there was no patches for 5.8.*, not sure why), but the system freezes after Loading initial ramdisk. Same thing ...
Meta-chan's user avatar
1 vote
0 answers
158 views

Ubuntu Studio 20.10 Loopback / Monitor Microphone Realtime

How could I further reduce delay? Audacity seems to add a bit more delay. So I have routed input to output, and enabled realtime, through QjackCtl. I still notice quite a bit of delay. I am at the ...
StudioTester's user avatar
1 vote
0 answers
215 views

Using RT kernel with Nvidia on Ubuntu Mate

I'm trying to use the linux-rt kernel in Ubuntu Mate. It installs and runs fine. The rub is, I need to retain Nvidia mode, as the laptop's hdmi output runs solely through the external card. With the ...
Thomas Furnari's user avatar
1 vote
0 answers
286 views

RT Patch on Raspberry pi 4 running ubuntu 18.04 LTS

So I've been using ubuntu 18.04 LTS on a raspberry pi 4 with 4GB RAM. I've found multiple articles explaining how install a preempt rt patch on AMD based systems but have been unable to so on my raspi....
Prateek Mahajan's user avatar
1 vote
0 answers
589 views

Support RTOS in Ubuntu 18.04 OS

I have installed Ubuntu 18.04 OS in my system, for configuring the Petalinux in my PC so that I can build real time application. For that, I have some queries related to this. How to enable realtime ...
Nithin sri parambudur's user avatar
2 votes
1 answer
255 views

Bash SH - Set a new var name including in that name another var

I just need to create an incremental var name inside a loop. The variable must use "in the var name the number of the cycle". Example inside a loop: # on Cycle=1 MyVar$Cycle=Exec$Cycle # (equal to ...
MauSH's user avatar
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0 answers
1k views

Unable to fix Real Time Permissions with Ubuntu Studio Control

What I expected to happen: Use the Ubuntu Studio Control app to set up real time (low latency) permissions What happened instead: When I click the button to fix real time permissions, it gives me a ...
semitones's user avatar
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1 vote
0 answers
254 views

Do we have any ways to retrieve the list of process and threads which are in runnable state(not running state) in ubuntu?

My requirement is to do dynamic cpu shielding in C program based on the queue length of runnable threads(but not running threads which are waiting for CPU availablity) in Realtime operating systems-(...
Siva Raj's user avatar
6 votes
1 answer
10k views

How do I get the newest lowlatency-kernel on 18.04 LTS?

When installing the linux-lowlatency package on 18.04 LTS, the lowlatency-kernel version 4.15 is installed, while the -generic kernel has been updated to 4.18 since the LTS release. 4.18 linux-...
Prototype700's user avatar
2 votes
0 answers
26 views

How can I efficiently record 3d games/3d programs in real-time?

As per subject would like to efficiently record 3d games/3d apps running full screen. I have an Nvidia 2080 Ti and I've heard about NVENC and obs-studio. Has anyone any suggestion? Can I just use it ...
Emanuele's user avatar
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0 votes
1 answer
489 views

Installing old kernel 3.4.69 in Linux 18.04 LTS

Can I possibly install a kernel 3.4.69 in place of the kernel 4.15? I have tried to do it for 3.4.4 and have been unsuccessful. What can I do? I really need 3.4.69 for Etherlab 2.1.
S_whynot's user avatar
1 vote
1 answer
549 views

Error in build while installing RTAI in Ubuntu 18.04

I am trying to install RTAI 5.0.1 on Ubuntu 18.04 LTS in Linux Kernel 4.1.18. I was following this tutorial. But unfortunately I am stuck in this part make -j `getconf _NPROCESSORS_ONLN` deb-pkg ...
S_whynot's user avatar
0 votes
1 answer
2k views

(initramfs) /cow format specified as aufs and no support found

I added a Real-Time patch to my existing Ubuntu 14.04 kernel to make it soft RT Linux. I've the steps for RT Linux here https://stackoverflow.com/questions/51669724/install-rt-linux-patch-for-ubuntu ...
Abhay Nayak's user avatar
2 votes
0 answers
119 views

Why is the canary starving? [duplicate]

I'm running Kubuntu 14.04 and my machine is nearly locked up. I apparently have a canary problem. Here is the log just before the bird started chirping: May 10 21:38:06 Morchella NetworkManager[1010]...
Paul A.'s user avatar
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1 vote
1 answer
4k views

Making Liquorix default kernel with native NVIDIA drivers for Ubuntu 16.04 for enhanced gaming and realtime functionality

I've been interested in running the Liquorix kernel for gaming and realtime performance enhancements. It's a pretty straight foward installation, but I found that it was incompatible with NVIDIA ...
ylluminate's user avatar
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3 votes
1 answer
5k views

Low Latency Kernel Downsides? [duplicate]

I'm considering moving from stock Ubuntu to Ubuntu Studio. My only concern is the low latency kernel. I've looked into what exactly it is, and know it will be great for my audio work, but I am ...
AdLinux's user avatar
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2 votes
1 answer
4k views

Problem with real-time clock since upgrading to Ubuntu 17.10

SEE UPDATES BELOW I recently upgraded from Ubuntu 17.04 to Ubuntu 17.10 using the software update process. The update completed without any errors, and Ubuntu 17.10 is now running without any major ...
pbmilley's user avatar
0 votes
1 answer
1k views

Realtime equalizer?

What realtime equalizers are there that work with JACK? I have heard of Calf Studio Gear, but not sure if it will work or how good it is. Ones that won't work are: pulseaudio-equalizer, jackeq, jamin....
Smiith's user avatar
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1 vote
0 answers
527 views

How to integrate Xenomai 3 with Nvidia cuda?

I use Ubuntu 16.04.2 64bits. I heard that Xenomai 2.x/3.x could not support Nvidia CUDA drivers. Is that true? If yes, how to solve it? Is there exist any software that can allocate one CPU ...
sam's user avatar
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23 votes
2 answers
115k views

timedatectl- NTP Sync cannot set to yes [duplicate]

I tried so much different things of installing ntpq or other stuff but nothing works. I dont can change it to yes. I hope someone can help here. I had Ubuntu 16.04 This is my terminal output of the ...
Scholli's user avatar
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3 votes
0 answers
1k views

Does Ubuntu Core support real-time?

Does Ubuntu Core's kernel support (hard) real-time? If not, is it using a standard kernel, which can be patched with the CONFIG_PREEMPT_RT set?
mystery's user avatar
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0 votes
1 answer
2k views

ulimit: Unknown option “-r”

I'm trying to get JACK running in RT mode and I need to determine whether I'm allowed the necessary real time priority. Around the internet I found that ulimit -r or more genreally ulimit -a can tell ...
zegkljan's user avatar
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1 vote
1 answer
2k views

JACK cannot start in realtime mode despite membership in audio group

My jack server is unable to start in realtime mode despite me being in the audio group. This is my setup: zegkljan@eddie:~$ lsb_release -r Release: 16.10 zegkljan@eddie:~$ echo $USER zegkljan ...
zegkljan's user avatar
  • 428
0 votes
1 answer
613 views

How to install realtime kernel on Ubuntu Live USB

I am using Ubuntu Live USB stick 16.04.1 with boot toram and persistence option. So far best sounding setup for audio streaming (Firefox+AdobeFlash+Tidal). It is also best setup in terms of usability ...
Miroslaw Kotecki's user avatar
0 votes
1 answer
418 views

Question about the RTAI and version Of kernel

I have a ubuntu 3.8.0-29 geniric and the gcc 4.6.3 . I will to install the RTAI , what is the version of kernel and the version of kernel to download ?
MohaMed's user avatar
0 votes
1 answer
1k views

How install Real Time Application Interface (RTAI) in ubuntu 14.04

I have Ubuntu 14.04 and I want to install rtai , my version kernel is : 3.16.0-30-generic. How to install the Real Time Application Interface Rtai of kernel 3.16.0-30-generic?
Karim Michel's user avatar
0 votes
1 answer
283 views

Problems compiling a kernel (3.4.110) on xubuntu 15.10

I am not sure if i am in the right forum for this, because it's more of a debian/kernel thing, but it is worth a try. I have to set up a linux system to work with EtherCAT ( for a machine control ). ...
ajtim's user avatar
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1 vote
1 answer
377 views

Hard disk's too slow to play a huge raw AVI file

I have a huge AVI file. The video player (VLC) stops every about 10 seconds because the HDD doesn't read fast enough. (details here) I want to be able to play this video. Anyone knows a workaround? ...
842Mono's user avatar
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0 votes
1 answer
853 views

VLC can't play large raw avi 1080p video

I recorded a huge raw avi video using SimpleScreenRecorder but it can't be played smoothly. Every about 10 seconds the video stops to render. How can I avoid this. I don't think my computer can't ...
842Mono's user avatar
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5 votes
1 answer
6k views

How to get to a perfect jackd configuration that works trouble-free and out of the box?

While working on a PPA to provide binaries for Sonic Pi, the users of the PPA binaries keep stumbling over jackd. How to make things easier for them? Sonic Pi is an educational music tool that ...
hez's user avatar
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