Re: [LAU] OS for realtime operation

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To: Moshe Werner <moshwe@...>
Cc: <linux-audio-user@...>
Date: Tuesday, January 10, 2012 - 12:07 am

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Hi Moshe,
The same here Ubuntu 10.04 with kernel 2.6.39 manually compiled, with
THREADIRQS enabled (which is the most important part of the RT kernel,
according to what I've learned here and read over there in the grid)

I can get 5.8 ms latency without xruns BUT having the WIFI disabled (no
IRQs are shared but it still cause a lot of xruns....)

I'm not a kernel expert, but I can say that you don't need to use a RT
Kernel in order to have a low latency. [1]

For instance, if you decide to give a try with Ubuntu, you can use the
default kernel and configure jack to use RT scheduling [2].
If that kernel is not suitable for you (I mean, you get a lot of xruns),
then you can use the PREEMPT or RT Kernels that are included in the
Official Ubuntu Repositories (which are configured in the apt sources
automatically) and see how it works before going to a manual kernel
compillation.

[1] http://jackaudio.org/realtime_vs_realtime_kernel
[2] http://jackaudio.org/linux_rt_config

Good luck and have fun.

2012/1/9 Moshe Werner

> Wow!

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Hi Moshe, The same here Ubuntu 10.04 with kernel 2.6.39 manually compil=
ed, with THREADIRQS enabled (which is the most important part of the RT ker=
nel, according to what I've learned here and read over there in the gri=
d)

I can get 5.8 ms latency without xruns BUT having the WIFI disabled (no=
IRQs are shared but it still cause a lot of xruns....)I'm not =
a kernel expert, but I can say that you don't need to use a RT Kernel i=
n order to have a low latency. [1]

For instance, if you decide to give a try with Ubuntu, you can use the =
default kernel and configure jack to use RT scheduling [2].If that kern=
el is not suitable for you (I mean, you get a lot of xruns), then you can u=
se the PREEMPT or RT Kernels that are included in the Official Ubuntu Repos=
itories (which are configured in the apt sources automatically) and see how=
it works before going to a manual kernel compillation.

[1] http:/=
/jackaudio.org/realtime_vs_realtime_kernel
[2] http://jackaudio.org/linux_rt_config

Good luck and have fun.2012/1/9 Moshe We=
rner <moshwe@gmail=
.com
>

Wow!Thank you for your knowledgeable inputs!It=
indeed seems that the openSuse distro is going into the direction of usual=
office use, too bad cause I already got accustomed to it.Will look=
into the options you listed. (Kxstudio probably try it out with Arch, or T=
ango studio)

Something little OT, but what exactly is the difference between Windows=
/Mac, where one doesn't need an rt kernel to run realtime processes, an=
d Linux which needs one? Please excuse my ignorance for as I said I&#39=
;m more the audio guy than computer guy.

Really appreciate your opinions!MosheOn Mon, Jan 9, 2012 at 11:06 PM, Jeremy Jongepier <jeremy@autostatic.com> wrote:

On 0=
1/09/2012 03:24 PM, Moshe Werner wrote:

Hi everyone,

after many years of studio work using the openSuse distro with the
kernel-rt from Jan Engelhard it seems that he no longer continues his great=

work on rt kernels.
Being more on the recording engineer side of things and not a Linux expert<=
br>
(user yes, expert no) I really fret at the thought of patching and
compiling my own kernel package.

I would like to hear your opinions on what distro is solid for audio work
and has a reliable rt kernel.
Also I would appreciate if you could explain the degree of difficulty and
learning curve of the specific distro.

My system:
Intel i7 950
Gigabyte motherboard
6 Gb ram
Rme HDSP 9652 audio interface

Appreciate your answers.

Moshe

P.S. I tried to use Ubuntu on the same machine I use openSuse 11.2 on and
got pretty bad results regarding latency and x runs on jack 2.

Hello Moshe,

Ubuntu 10.04 here with the Tango Studio real-time kernel. Latency-wise I ca=
n go as low as the soundcard allows. If I have any xruns that shouldn't=
be there I search just as long until it's solved. I still prefer Ubunt=
u because it is one of the biggest distro's and that comes with some ad=
vantages. I'm also very fond of the PPA system (Personal Package Archiv=
es) and that Ubuntu is akin of Debian. I've used Fedora and Mandriva (b=
oth RPM based) for a long time but prefer the Debian way for a lot of thing=
s (packaging, filesystem layout). Also Ubuntu LTS releases just work, at le=
ast, in my experience. And they're stable, especially after the first p=
oint release (10.04 is at 10.04.3 now).

I'm also dabbling with Arch at the moment. I like it, it was a lot like=
coming home but Arch also has some major drawbacks. The packaging system i=
s a huge security flaw, especially when you use AUR. Anyone can upload anyt=
hing (this is possible with Ubuntu PPA's too but it's a lot harder)=
. Other than that AUR is simply amazing, compared to Debian/Ubuntu packagin=
g is a breeze. Other thing are the rough edges. Ubuntu is polished, especia=
lly when it comes to the desktop experience. I've come to appreciate th=
at through the years so I had a rough time getting font rendering right for=
instance, and it still doesn't look and feel like on my Ubuntu install=
. But Arch does have its pros. It's a rolling release so you only have =
to install it once and then you're good to go for years to come. This w=
ill also ensure that you're always running a pretty up to date system. =
Which could also be a disadvantage. I'm a Jack1 user for instance but a=
lso a seq24 user and seq24 doesn't work with Jack transport with versio=
ns > 0.118.x. So 0.121.x that is in Arch at the moment doesn't fly f=
or me. The biggest pros for me are the configurability and that everything =
is so well documented. I LOVE opening a terminal on Arch and configure stuf=
f that way because it's so easy and fun.

I'm not very fond of specialized multimedia/audio distro's. I want =
to configure a system the way I want, most of the distro's do things a =
different way or just wrong in my opinion. Also most of these distro's =
are driven by incredibly small communities or simply just one person. Conti=
nuity is not assured. I do check them every now and then and cherry pick th=
e good stuff and integrate it on my own system. If I'd have to choose a=
multimedia distro though I would most certainly choose AVLinux, closely fo=
llowed by Tango Studio. GMaq and Jof are simply very knowledgable guys and =
listen well to what users have to say.

In your case I think Arch might be a bit too much expert. If you're com=
ing from OpenSuSE you might want to try Fedora with the CCRMA repo or give =
Ubuntu another try, it is a Linux flavour after all so Jack should be able =
to run with acceptable latencies. Or stick with OpenSuSE and hope someone i=
s willing to take over maintaining a real-time kernel.

Best,

Jeremy
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Linux-audio-user@lists.linuxaudio.org

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Messages in current thread:
[LAU] OS for realtime operation, Moshe Werner, (Mon Jan 9, 2:24 pm)
Re: [LAU] OS for realtime operation, Carlos sanchiavedraz, (Wed Jan 11, 2:43 pm)
Re: [LAU] OS for realtime operation, Josh Lawrence, (Thu Jan 12, 8:07 pm)
Re: [LAU] OS for realtime operation, Carlos sanchiavedraz, (Fri Jan 13, 12:02 pm)
Re: [LAU] OS for realtime operation, david, (Wed Jan 11, 5:05 pm)
Re: [LAU] OS for realtime operation, Dave Phillips, (Wed Jan 11, 2:47 pm)
Re: [LAU] OS for realtime operation, Carlos sanchiavedraz, (Thu Jan 12, 8:11 am)
Re: [LAU] OS for realtime operation, david, (Thu Jan 12, 8:25 am)
Re: [LAU] OS for realtime operation, Carlos sanchiavedraz, (Thu Jan 12, 4:08 pm)
Re: [LAU] OS for realtime operation, david, (Thu Jan 12, 6:00 pm)
Re: [LAU] OS for realtime operation, michael noble, (Tue Jan 10, 12:47 am)
Re: [LAU] OS for realtime operation, Ronald Stewart, (Tue Jan 10, 1:05 am)
Re: [LAU] OS for realtime operation, Jeremy Jongepier, (Mon Jan 9, 9:06 pm)
Re: [LAU] OS for realtime operation, Moshe Werner, (Mon Jan 9, 10:01 pm)
Re: [LAU] OS for realtime operation, Jeremy Jongepier, (Tue Jan 10, 9:02 am)
Re: [LAU] OS for realtime operation, Paul Davis, (Tue Jan 10, 12:44 pm)
Re: [LAU] OS for realtime operation, tee, (Thu Jan 12, 4:15 pm)
Re: [LAU] OS for realtime operation, david, (Fri Jan 13, 4:59 am)
Re: [LAU] OS for realtime operation, Raffaele Morelli, (Fri Jan 13, 7:45 am)
Re: [LAU] OS for realtime operation, Nicola Pandini, (Sat Jan 14, 10:38 am)
Re: [LAU] OS for realtime operation, Moshe Werner, (Mon Feb 20, 7:38 am)
Re: [LAU] OS for realtime operation, david, (Fri Jan 13, 8:43 am)
Re: [LAU] OS for realtime operation, fred, (Tue Jan 10, 7:17 pm)
Re: [LAU] OS for realtime operation, Moshe Werner, (Wed Jan 11, 1:11 pm)
Re: [LAU] OS for realtime operation, Fons Adriaensen, (Wed Jan 11, 2:55 pm)
Re: [LAU] OS for realtime operation, Brett McCoy, (Wed Jan 11, 1:39 pm)
Re: [LAU] OS for realtime operation, Diego Simak, (Tue Jan 10, 12:07 am)
Re: [LAU] OS for realtime operation, Jeremy Jongepier, (Tue Jan 10, 8:15 am)
Re: [LAU] OS for realtime operation, gene heskett, (Tue Jan 10, 2:43 pm)
Re: [LAU] OS for realtime operation, Jeremy Jongepier, (Tue Jan 10, 3:13 pm)
Re: [LAU] OS for realtime operation, Hartmut Noack, (Mon Jan 9, 5:29 pm)
Re: [LAU] OS for realtime operation, Moshe Werner, (Mon Jan 9, 5:53 pm)
Re: [LAU] OS for realtime operation, Hartmut Noack, (Mon Jan 9, 9:05 pm)
Re: [LAU] OS for realtime operation, Raffaele Morelli, (Mon Jan 9, 3:05 pm)
Re: [LAU] OS for realtime operation, Moshe Werner, (Mon Jan 9, 3:23 pm)
Re: [LAU] OS for realtime operation, Raffaele Morelli, (Tue Jan 10, 7:02 am)
Re: [LAU] OS for realtime operation, Fons Adriaensen, (Mon Jan 9, 4:03 pm)
Re: [LAU] OS for realtime operation, Joe Hartley, (Mon Jan 9, 3:58 pm)
Re: [LAU] OS for realtime operation, Moshe Werner, (Mon Jan 9, 4:24 pm)