23 Jul
2003
23 Jul
'03
4:49 a.m.
Hi list
I remember leading somewhere over a year ago that the low latency patch
maybe was making it's way into the actual kernel, something about Linus
needed to approve it or something. Is this still underway?
--
peace, love & harmony
Atte
23 Jul
23 Jul
5:44 a.m.
Hallo,
Atte André Jensen hat gesagt: // Atte André Jensen wrote:
I remember leading somewhere over a year ago that the
low latency patch
maybe was making it's way into the actual kernel, something about Linus
needed to approve it or something. Is this still underway?
The preemptible kernel patch is now part of the 2.5/6 series. It gives
quite good latency, so I heard. Which brings up these questions:
* Who is already using a 2.5 kernel?
* How's it working? Would you recommend going 2.5?
* What is needed to use 2.5?
* When will 2.6 come out?
I'd be glad to hear some comments.
ciao
--
Frank Barknecht _ ______footils.org__
6:11 a.m.
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Frank Barknecht wrote:
| Hallo,
| Atte André Jensen hat gesagt: // Atte André Jensen wrote:
|
|>I remember leading somewhere over a year ago that the low latency patch
|>maybe was making it's way into the actual kernel, something about Linus
|>needed to approve it or something. Is this still underway?
|
| The preemptible kernel patch is now part of the 2.5/6 series. It gives
| quite good latency, so I heard. Which brings up these questions:
|
| * Who is already using a 2.5 kernel?
| * How's it working? Would you recommend going 2.5?
| * What is needed to use 2.5?
| * When will 2.6 come out?
|
| I'd be glad to hear some comments.
|
| ciao
I think low latency and preempt patches are backported on 2.4
and installed by default on desktop installations
in mainstream distros such as Mandrake and RedHat.
Someone to confirm ? How to check if this is right or wrong ?
Nyco
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1:07 p.m.
Nicolas VERITE (Nÿco) escribio el 23/07/03 09:59:
I think low latency and preempt patches are backported
on 2.4
and installed by default on desktop installations
in mainstream distros such as Mandrake and RedHat.
I don't know about RedHat, but I don't think Mandrake 9.1 installs a
patched kernel by default. Nevertheless, you have easy access to one of
them given that contrib sources are setup for urpmi:
# urpmi kernel-multimedia
Check out this glorious article, "The Mandrake Audio Workstation HowTo".
http://www.desktoplinux.com/articles/AT8018846552.html
For RedHat, I think Planet CCRMA is also including a "multimedia"
patched kernel.
Regards, Ismael
1:56 p.m.
On 2003.07.23 10:54, Ismael Valladolid Torres wrote:
I don't know about RedHat, but I don't think
Mandrake 9.1 installs a
patched kernel by default. Nevertheless, you have easy access to one
of them given that contrib sources are setup for urpmi:
# urpmi kernel-multimedia
Check out this glorious article, "The Mandrake Audio Workstation
HowTo".
http://www.desktoplinux.com/articles/AT8018846552.html
Hehe, thanks for the citation. :-)
Danny is currently working on the multimedia kernel for Mandrake 9.2
beta, which will be based on 2.4.21 and include some extra scheduling
patches in addition to low-lat and pre-empt. I have been testing it
lately and it shows marked improvement in latency with jackit over the
current multimedia kernel.
Austin
1:17 p.m.
On Wed 23/07/2003 09:59:47, "Nicolas VERITE (Nÿco)" wrote:
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Hash: SHA1
Frank Barknecht wrote:
| Hallo,
| Atte André Jensen hat gesagt: // Atte André Jensen wrote:
|
|>I remember leading somewhere over a year ago that the low latency patch
|>maybe was making it's way into the actual kernel, something about Linus
|>needed to approve it or something. Is this still underway?
|
| The preemptible kernel patch is now part of the 2.5/6 series. It gives
| quite good latency, so I heard. Which brings up these questions:
|
| * Who is already using a 2.5 kernel?
| * How's it working? Would you recommend going 2.5?
| * What is needed to use 2.5?
| * When will 2.6 come out?
|
| I'd be glad to hear some comments.
|
| ciao
I think low latency and preempt patches are backported on 2.4
and installed by default on desktop installations
in mainstream distros such as Mandrake and RedHat.
Someone to confirm ? How to check if this is right or wrong ?
cat /proc/sys/kernel/lowlatency
is one thing ...
and the config options in the kernel are these:
CONFIG_LOLAT=y
CONFIG_LOLAT_SYSCTL=y
CONFIG_PREEMPT=y
If you have the .config for your kernel you can grep for these to see
if they are turned on. debian keeps a copy of your kernel's config file
in /boot, not sure if/where other distros put it.
Nyco
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6:14 a.m.
Frank Barknecht wrote:
Hallo,
Atte André Jensen hat gesagt: // Atte André Jensen wrote:
me.
I remember leading somewhere over a year ago that
the low latency patch
maybe was making it's way into the actual kernel, something about Linus
needed to approve it or something. Is this still underway?
The preemptible kernel patch is now part of the 2.5/6 series. It gives
quite good latency, so I heard. Which brings up these questions:
* Who is already using a 2.5 kernel? * How's it working? Would you recommend going 2.5?
fine. EXCEPT: DO NOT USE TAGGED COMMAND QUEUING FOR ATA DISKS !!!!!!
sorry for yelling, but this thing ate 200G worth of data....
:)
other than that, it's been quite well-behaved.
* What is needed to use 2.5?
/usr/src/linux/Documentation/Changes
expect to update a number of userspace tools, most notably modutils.
* When will 2.6 come out?
when it's ready :)
you might be happy to hear that linus has released 2.6.0-test1. not that
this has any significance whatsoever. :)
--
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the threat or use of force against the territorial integrity or
political independence of any state, or in any other manner
inconsistent with the Purposes of the United Nations.
-- Charter of the United Nations, Article 2.4
Jörn Nettingsmeier
Kurfürstenstr 49, 45138 Essen, Germany
http://spunk.dnsalias.org (my server)
http://www.linuxdj.com/audio/lad/ (Linux Audio Developers)
7:32 a.m.
Hallo,
Joern Nettingsmeier hat gesagt: // Joern Nettingsmeier wrote:
I'm running Debian unstable, so I probably already have most of these.
I expected this answer. ;) 2.4 had a very long 2.4.0-testX phase, but
at least this has started the beta phase for the next version.
Actually I'm asking for experiences with 2.5 because I'm writing an
article on setting up a Linux audio workstation and I'm wondering if I
should cover the 2.5-series in more depth than just saying: "2.5 has
better latency built in, but use it only if you know what you're
doing". But then, maybe instead of explaining how to patch the
2.4-kernel, I could just say: "install 2.5 and enable ALSA. Now on to
installing Jack..." ;)
ciao
--
Frank Barknecht _ ______footils.org__
Frank Barknecht wrote:
Thanks for that info! But we all have backups. haven't we. (/me
blushes)
* How's it working? Would you recommend going
2.5?
fine. EXCEPT: DO NOT USE TAGGED COMMAND QUEUING FOR ATA DISKS !!!!!!
sorry for yelling, but this thing ate 200G worth of data....
:)
other than that, it's been quite well-behaved. * What is
needed to use 2.5?
/usr/src/linux/Documentation/Changes
expect to update a number of userspace tools, most notably modutils. * When will 2.6
come out?
when it's ready :)
you might be happy to hear that linus has released 2.6.0-test1. not that
this has any significance whatsoever. :) 
12:14 p.m.
On Wed, Jul 23, 2003 at 11:18:54AM +0200, Frank Barknecht wrote:
I'm
running Debian unstable, so I probably already have most of these.
actually, you'll probably have to get 'module-init-tools' for modules to load
properly under 2.5/2.6. It sits alongside the old 2.4 one, and doesn't cause any
problem with older kernels.
The other problem I've had is that when trying to use devfsd with the 2.5/2.6 kernel,
permissions on some of the /dev nodes are set wrong causing all sorts of problems trying
to run stuff. I've generally found it better to not use devfs with 2.5/2.6 for now ..
A patch is also available for the nvidia closed-source drivers at http://www.minion.de/ to
allow building against 2.5/2.6.
otherwise, I've been using the 2.6 kernel a fair bit and have been having very good
experiences. I've noticed some audio stuttering in neverwinter nights using an audigy2
w/ alsa that I never experienced with 2.4, but generally 2.5/2.6 feels faster.
later,
Steve
* What is needed to use 2.5?
/usr/src/linux/Documentation/Changes
expect to update a number of userspace tools, most notably modutils. 
3 p.m.
On Wed, Jul 23, 2003 at 06:57:59AM -0700, Stephen Hassard wrote:
On Wed, Jul 23, 2003 at 11:18:54AM +0200, Frank
Barknecht wrote:
I'm
running Debian unstable, so I probably already have most of these.
actually, you'll probably have to get 'module-init-tools' for modules to load
properly under 2.5/2.6. It sits alongside the old 2.4 one, and doesn't cause any
problem with older kernels.
module-init-tools will move the respective tools from modutils out of the way
by renaming them to "*.modutils"
Modules are now configured in /etc/modprobe.conf and /etc/modprobe.d/*,
'update-modules' will build /lib/modules/modprobe.conf out of these.
When changing your 2.4.x config in /etc/modutils/* you now need to run
'update-modules.modutils' to build /etc/modules.conf.
cheers,
Christian Henz
* What is needed to use 2.5?
/usr/src/linux/Documentation/Changes
expect to update a number of userspace tools, most notably modutils. 
6:48 a.m.
The preemptible kernel patch is now part of the 2.5/6
series. It gives
quite good latency, so I heard. Which brings up these questions:
* Who is already using a 2.5 kernel?
$ uname -ra
Linux mtg62 2.5.72 #1 Wed Jun 18 13:55:19 CEST 2003 i686 unknown unknown GNU/Linux
:-)
* How's it working? Would you recommend going 2.5?
Very well. I have rebooted only once, after a 15 day uptime, when an rmmod of a
SCSI driver module did not return (but no freeze of the kernel itself). So as
far as I can see, it is very stable. It is not the latest 2.5.72, but I would
say that in general things have only improved since then.
As for audio, first of all it is very nice to have ALSA included, and as far
low latency/responsiveness, I can only see that it "feels" good. I have not
run any of the stress tests though, but under a normal workload, I get no
underruns. What is more, with 2.4.20 I had, even with the LL en PE patches,
some problems with underruns and X getting slugish during heavy disk access.
I suppose the 2.5.72 kernel has better support for the IDE DMA on my mainboard.
* What is needed to use 2.5?
What do you mean? Some guts and a bit patience I guess :-)
Maarten
7:22 a.m.
On Wed, Jul 23, 2003 at 10:33:47AM +0200, Maarten de Boer wrote:
low latency/responsiveness, I can only see that it
"feels" good. I have not
run any of the stress tests though, but under a normal workload, I get no
underruns. What is more, with 2.4.20 I had, even with the LL en PE patches,
Hey Maarten :)
Could you run latencytest when you have some spare time ?
I would be very interested in the results.
Do you have any IDE disks in there or is it an all scsi system ?
best regards,
Vincent
8:42 a.m.
Could you run latencytest when you have some spare
time ?
I would be very interested in the results.
I will, when I have some spare time. Don't hold your breath though :-)
Do you have any IDE disks in there or is it an all
scsi system ?
The harddisk is IDE, the SCSI is only for an external CD burner.
Maarten
7:29 a.m.
Maarten de Boer wrote:
As for audio, first of all it is very nice to have ALSA
included, and as far
low latency/responsiveness
What version of ALSA is in the kernels, both 2.5* and 2.6?
And isn't it better to compile the drivers from sources, and keep them
updated
regularly?
-- Rossen
8:01 a.m.
On Wed, Jul 23, 2003 at 06:24:48PM +0900, rossen wrote:
Maarten de Boer wrote:
AFAIK, alsa in 2.6 is the very latest.
Updates happen in the mainline kernel tree, as alsa is accepted.
There is no need for a separate tree, as that would only mean overhead.
regards,
vincent
As for audio, first of all it is very nice to have
ALSA included, and as far
low latency/responsiveness
What version of ALSA is in the kernels, both 2.5* and 2.6?
And isn't it better to compile the drivers from sources, and keep them
updated
regularly?
7590
days inactive
7590
days old
linux-audio-user@lists.linuxaudio.org
14 comments
12 participants
participants (12)
-
"Nicolas VERITE (Nÿco)" -
Atte André Jensen -
Austin -
Christian Henz -
Eric Dantan Rzewnicki -
Frank Barknecht -
Ismael Valladolid Torres -
Joern Nettingsmeier -
Maarten de Boer -
rossen -
Stephen Hassard -
Vincent Touquet