Debian 8 (jessie)

What other apps and distros do you use to round out your studio?

Moderators: khz, MattKingUSA

tizo
Established Member
Posts: 18
Joined: Tue Dec 16, 2014 10:54 pm

Debian 8 (jessie)

Post by tizo »

Hi there,

I'm new to the list, but have some experience about playing music and audio production with GNU/Linux. I have a pristine installation of Debian 8 with XFCE for using with audio. I was going to compile a custom Kernel with RT patch, when I noted that the patch was not ready for the Kernel version that comes with jessie (3.16.0). After a little research, I have seen that Thomas Gleixner, the principal maintainer of RT patch, is a little tired of having no funds for this work, and from now on, will start to do the work just as a hobby (http://lwn.net/Articles/617140/). Just for the records, I have tried different distributions and/or kernels over the last years, and a custom RT patched kernel in Debian (with XFCE an innecesary services deactivated), has been by far the best solution to obatin the lowest latencies without xruns.

As a consequence, I have been thinking about the future of RT kernels, and other alternatives. So I would like to hear your opinion about the following items:

* Are you still using RT patched kernels for playing music an audio productions?. Or are you trusting in newer hardware and newer kernels that have some improvements to achieve lower latencies?. In the first case, wouldn't be great to organize a site or something to make donations for Thomas to continue to develop RT patch in a more professional way?.

* In the meanwhile, I am thinking on compiling the jessie stock Kernel withouth RT of course, but with some configurations as "CONFIG_HZ=1000" and "CONFIG_NO_HZ=y". Is not so difficult to compile a Kernel in de "Debian way" after doing it one or two times. Any ideas of wich other configurations would be good to achieve low latencies?.

* I have read about other Kernels that seems promising for audio production. They are Cadence, Tango, Siduction, etc. Some of them have the RT patch applied (of course, versions lowers than 3.16.0) and some not. What do you think about those?. Any clue on how to use them on Debian jessie?.

Thanks very much,

tizo

User avatar
GMaq
Established Member
Posts: 1795
Joined: Fri Sep 25, 2009 1:42 pm

Re: Debian 8 (jessie)

Post by GMaq »

Hi,

In my experience the need for RT patching almost became obsolete a few years ago when the ability to prioritize IRQ's and use 'rtirq' entered the mainline kernel... but then USB-2 class-compliant devices began to appear and work with Linux and it seems many of them benefit significantly from RT preempt. In my own small studio we have a Presonus 1818VSL and my son has a Focusrite Scarlett 2i2, both of these devices perform with MUCH lower latencies using an RT Kernel, on the other hand an older Mackie ONYX Mixer with the FireWire option does not show any better performance when using RT vs. lowlatency kernels and an M-Audio 1010LT PCI card also performs almost equally well with either kernel..

As far as I'm concerned it is almost completely dependent on the hardware combinations you are using including both the PC itself and whatever Audio hardware you are using it with. I think there will always be cases in Audio work that necessitate an RT option. In AV Linux this is done by shipping an optional RT kernel right on the LiveDVD so the user can choose after installing, it would certainly be a sad thing to see RT optional kernels disappear from distros like Debian (Ubuntu has already abandoned it years ago) and to have end-users have to once again resorting to building their own..

User avatar
khz
Established Member
Posts: 1447
Joined: Thu Apr 17, 2008 6:29 am
Location: German

Re: Debian 8 (jessie)

Post by khz »

Jup The future of realtime Linux
There is a rt-sources-3.14.25_p22 Kernel, boots fine with Intel, but not with AMD (my testing). >> http://gpo.zugaina.org/sys-kernel/rt-sources
FZ - Does humor belongs in Music?
GNU/LINUX@AUDIO ~ /Wiki $ Howto.Info && GNU/Linux Debian installing >> Linux Audio Workstation LAW
  • I don't care about the freedom of speech because I have nothing to say.

lazyklimm
Established Member
Posts: 244
Joined: Tue Jul 23, 2013 4:59 pm

Re: Debian 8 (jessie)

Post by lazyklimm »

>I have read about other Kernels that seems promising for audio production. They are Cadence, Tango, Siduction, etc. Some of them have the RT patch applied (of course, versions lowers than 3.16.0) and some not. What do you think about those?. Any clue on how to use them on Debian jessie?.

I use liquorix one, works better for me

User avatar
thetotalchaos
Established Member
Posts: 184
Joined: Mon Sep 29, 2014 8:29 pm
Contact:

Re: Debian 8 (jessie)

Post by thetotalchaos »

In order to use the generic Linux kernel in Audio, it should have at least 'PREEMPT' option enabled. You can check this with the command 'uname -a' like:

Code: Select all

$ uname -a
Linux totalchaos 3.17.6-1-ARCH #1 SMP PREEMPT Sun Dec 7 23:43:32 UTC 2014 x86_64 GNU/Linux
This option gives you the ability to have realtime priorities. Without it you must have a very powerful hardware, and/or you don't attempt to have low-latency settings. Note that the stock Debian kernel doesn't have this option, but the default kernels in Trisquel and Arch has it.
Check out my latest music album The girl with the stars in her eyes
https://totalchaos-music.bandcamp.com/a ... n-her-eyes

User avatar
khz
Established Member
Posts: 1447
Joined: Thu Apr 17, 2008 6:29 am
Location: German

Re: Debian 8 (jessie)

Post by khz »

Compile your own Kernel.
Example for Gentoo: http://gentoostudio.org/index.php/manua ... the-kernel
Processor type and features --->
Preemption Model (Fully Preemptible Kernel (RT)) --->
( ) No Forced Preemption (Server)
( ) Voluntary Kernel Preemption (Desktop)
( ) Preemptible Kernel (Low-Latency Desktop)
(X) Fully Preemptible Kernel (RT)

Processor type and features --->
Timer frequency (1000 HZ) --->
(X) 1000 HZ
Normal Kernel you have only

Code: Select all

(X) Preemptible Kernel (Low-Latency Desktop)
.
I have currently a .17 Low-Latency Desktop Kernel, everything fine.
FZ - Does humor belongs in Music?
GNU/LINUX@AUDIO ~ /Wiki $ Howto.Info && GNU/Linux Debian installing >> Linux Audio Workstation LAW
  • I don't care about the freedom of speech because I have nothing to say.

tizo
Established Member
Posts: 18
Joined: Tue Dec 16, 2014 10:54 pm

Re: Debian 8 (jessie)

Post by tizo »

GMaq wrote:Hi,

In my experience the need for RT patching almost became obsolete a few years ago when the ability to prioritize IRQ's and use 'rtirq' entered the mainline kernel... but then USB-2 class-compliant devices began to appear and work with Linux and it seems many of them benefit significantly from RT preempt. In my own small studio we have a Presonus 1818VSL and my son has a Focusrite Scarlett 2i2, both of these devices perform with MUCH lower latencies using an RT Kernel, on the other hand an older Mackie ONYX Mixer with the FireWire option does not show any better performance when using RT vs. lowlatency kernels and an M-Audio 1010LT PCI card also performs almost equally well with either kernel..

As far as I'm concerned it is almost completely dependent on the hardware combinations you are using including both the PC itself and whatever Audio hardware you are using it with. I think there will always be cases in Audio work that necessitate an RT option. In AV Linux this is done by shipping an optional RT kernel right on the LiveDVD so the user can choose after installing, it would certainly be a sad thing to see RT optional kernels disappear from distros like Debian (Ubuntu has already abandoned it years ago) and to have end-users have to once again resorting to building their own..
Thanks for your response. In my case, I have been using a cheap Beringher USB card, and in this case, the RT patched kernels have performed much better. It was my mistake to generalize that case for all the universe of combinations. However, I don't know on what you are working on, but (and I am guessing here) when playing midi instruments, RT Kernels seems to be more important than for audio production.

Just for the records, I don't even know if Debian will provide an RT compiled Kernel for jessie (besides that I have no problem in compile my own one). I have just mentioned that RT patch development cycle is in danger, and this problem is not pertinent to a particular distribution.

AV Linux seems promising, but I am so used to work with Debian (I work on IT), that I would prefer to continue like this. I am just looking for the best Kernel to work with it for playing midi instruments an audio productions.

tizo
Established Member
Posts: 18
Joined: Tue Dec 16, 2014 10:54 pm

Re: Debian 8 (jessie)

Post by tizo »

khz wrote:There is a rt-sources-3.14.25_p22 Kernel, boots fine with Intel, but not with AMD (my testing). >> http://gpo.zugaina.org/sys-kernel/rt-sources
Thanks khz. I know that the RT patch is ready for 3.14 kernels; what is interesting here that the sources are already patched. If a custom compiled "on the Debian way" 3.16 Kernel (with no RT of course) does not perform too well with my hardware, maybe I'll try this option.

tizo
Established Member
Posts: 18
Joined: Tue Dec 16, 2014 10:54 pm

Re: Debian 8 (jessie)

Post by tizo »

lazyklimm wrote:>I have read about other Kernels that seems promising for audio production. They are Cadence, Tango, Siduction, etc. Some of them have the RT patch applied (of course, versions lowers than 3.16.0) and some not. What do you think about those?. Any clue on how to use them on Debian jessie?.

I use liquorix one, works better for me
Thanks lazyklimm. Using Liquorix kernels in Debian seems to be really easy (http://www.instructables.com/id/Install ... sed-Linux/). Do you know what configurations does it have that makes it suitable for working with audio?.

tizo
Established Member
Posts: 18
Joined: Tue Dec 16, 2014 10:54 pm

Re: Debian 8 (jessie)

Post by tizo »

khz wrote:Compile your own Kernel.
Of course. I am willing to do that. Only that I prefer to do it in the Debian way (I am used to do it), but 3.16 RT patch is not ready, and Debian jessie is not providing 3.14 kernels.

tizo
Established Member
Posts: 18
Joined: Tue Dec 16, 2014 10:54 pm

Re: Debian 8 (jessie)

Post by tizo »

thetotalchaos wrote:In order to use the generic Linux kernel in Audio, it should have at least 'PREEMPT' option enabled. You can check this with the command 'uname -a' like:

Code: Select all

$ uname -a
Linux totalchaos 3.17.6-1-ARCH #1 SMP PREEMPT Sun Dec 7 23:43:32 UTC 2014 x86_64 GNU/Linux
This option gives you the ability to have realtime priorities. Without it you must have a very powerful hardware, and/or you don't attempt to have low-latency settings. Note that the stock Debian kernel doesn't have this option, but the default kernels in Trisquel and Arch has it.
Thanks thetoalchaos. So I think that compiling 3.16 generic kernel with "CONFIG_HZ=1000", "CONFIG_NO_HZ=y" and "CONFIG_PREEMPT=y" will be my first shot. Do you reccomend other options?. What about the options listed in https://wiki.ubuntu.com/UbuntuStudio/rtirq to use rtirq script?

User avatar
khz
Established Member
Posts: 1447
Joined: Thu Apr 17, 2008 6:29 am
Location: German

Re: Debian 8 (jessie)

Post by khz »

tizo wrote:Only that I prefer to do it in the Debian way (I am used to do it), but 3.16 RT patch is not ready,
The .14-rt is the newest https://www.kernel.org/pub/linux/kernel/projects/rt/
(Gentoo/Debian/Arch/... it's all GNU/Linux)
tizo wrote:to use rtirq script?
http://wiki.linuxaudio.org/wiki/system_ ... tion#rtirq
FZ - Does humor belongs in Music?
GNU/LINUX@AUDIO ~ /Wiki $ Howto.Info && GNU/Linux Debian installing >> Linux Audio Workstation LAW
  • I don't care about the freedom of speech because I have nothing to say.

tizo
Established Member
Posts: 18
Joined: Tue Dec 16, 2014 10:54 pm

Re: Debian 8 (jessie)

Post by tizo »

As for now, my first shot is working like a charm. 3.16 kernel recompiled wit options CONFIG_PREEMPT=y, CONFIG_HZ=1000, CONFIG_NO_HZ_IDLE=y and CONFIG_IRQ_FORCED_THREADING=y (the last one is enabled by default in stock Debian kernel 3.16). I have neither tried rtirq script yet, nor disabled any services, but still listening to an ardour proyect with 23 tracks (no plugins yet), and using Internet with 0 xrun!.

I will be posting about the progress with other uses. Thanks you all!.

asbak
Established Member
Posts: 647
Joined: Thu Sep 11, 2014 3:04 pm

Re: Debian 8 (jessie)

Post by asbak »

I have two major problems on Jessie

One being the standard kernel (can't seem to get rid of intermittent xruns with a RME PCI card)
getting jack2 to work reliably

Because there's an nVidia card on the computer and a recent driver got loaded which requires a 3.16 kernel it looks like the system isn't coming up when booting it with older RT kernels. (Presumably the video hangs). So not having a recent RT kernel is a bit of a letdown. The information on creating a PREEMPT kernel is interesting though, thanks for this.

Jack2 just never seems to work properly, when left running for hours it will eventually start xrunning by itself. It is unreliable when using audio apps, working fine for a while and then suddenly either xrunning or hanging audio apps. Basically, it seems near unusable. Are there viable options out there to avoid jack altogether or to configure it in such a way that it actually works reliably? Is jack1 more reliable?

juki
Established Member
Posts: 67
Joined: Sun Mar 29, 2009 10:45 pm

Re: Debian 8 (jessie)

Post by juki »

Debian Jessie works very wll here with jackd1 and Liquorix kernel.

Post Reply