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#1 2005-06-14 10:29:36

blitze
Member
From: Melbourne, Australia
Registered: 2004-03-19
Posts: 54

Kernel26mm alternative?

Would it be possible to have a standard 26 kernel with a realtime module that can be loaded and unlaoded at the users will?

Would save us having to deal with having 2 kernel boot options and associated display driver issues.

Am I dreaming?  :?


Leave ones footprint not in the physical world but the in the world of the mind.

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#2 2005-06-14 12:05:31

iphitus
Forum Fellow
From: Melbourne, Australia
Registered: 2004-10-09
Posts: 4,927

Re: Kernel26mm alternative?

what's this 'realtime' module you speak of?

if its the RT patches that have been touted around they dont really offer any improvements unless you are doing some heavyweight audio or video editing......

iphitus

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#3 2005-06-14 12:38:39

dtw
Forum Fellow
From: UK
Registered: 2004-08-03
Posts: 4,439
Website

Re: Kernel26mm alternative?

there's plenty of alternatives to mm too - just not binaries

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#4 2005-06-14 17:06:20

phrakture
Arch Overlord
From: behind you
Registered: 2003-10-29
Posts: 7,879
Website

Re: Kernel26mm alternative?

blitze wrote:

Would it be possible to have a standard 26 kernel with a realtime module that can be loaded and unlaoded at the users will?

Would save us having to deal with having 2 kernel boot options and associated display driver issues.

Am I dreaming?  :?

I don't understand... what is a "realtime" module? how would this save you from dealing with multiple boot options? is this a feature from mm that you want in the stock kernel?

I'm confizzled

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#5 2005-06-14 19:23:16

Gullible Jones
Member
Registered: 2004-12-29
Posts: 4,863

Re: Kernel26mm alternative?

Are you talking about the RTC module? That's available in all kernels...

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#6 2005-06-14 23:46:50

blitze
Member
From: Melbourne, Australia
Registered: 2004-03-19
Posts: 54

Re: Kernel26mm alternative?

Realtime kernel options in a module for insertion when I want to Audio work utlising Jack with realtime as a user not root.  Instead of having to run a separate kernel26mm which would require shutting down then restarting the system from a cold boot (to intialise sound hardware) and then dealing with Nvidia driver issues due to the different kernel.

If the module is called the RTC and gives the same funtionality to the standard kernel26 as the the kernel26mm then yes.  If not, then what are my options?

Is that a bit clearer?


Leave ones footprint not in the physical world but the in the world of the mind.

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#7 2005-06-15 00:01:18

Dusty
Schwag Merchant
From: Medicine Hat, Alberta, Canada
Registered: 2004-01-18
Posts: 5,986
Website

Re: Kernel26mm alternative?

RTC is the realtime clock...

It sounds you you just want modprobe... that's installed by default.

I think we're still confused as to what you want.

Dusty

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#8 2005-06-15 02:09:19

Gullible Jones
Member
Registered: 2004-12-29
Posts: 4,863

Re: Kernel26mm alternative?

Oh... A realtime kernel? I don't think kernel26mm provides that. There might be a  realtime patchset out there somewhere...

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#9 2005-06-15 06:13:48

jochen
Member
From: Germany
Registered: 2004-06-01
Posts: 102

Re: Kernel26mm alternative?

The "realtime module": http://sourceforge.net/projects/realtime-lsm/

Neri wrote why this can't be included in stock kernel here:
http://bbs.archlinux.org/viewtopic.php?t=9356&start=15

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#10 2005-06-15 09:28:43

blitze
Member
From: Melbourne, Australia
Registered: 2004-03-19
Posts: 54

Re: Kernel26mm alternative?

Yea, someone knows what I'm talking about.  Can it be done and save many of us a Linux dual boot for when we want to work with audio?


Leave ones footprint not in the physical world but the in the world of the mind.

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#11 2005-06-15 10:56:50

neri
Forum Fellow
From: Victoria, Canada
Registered: 2003-05-04
Posts: 553

Re: Kernel26mm alternative?

blitze wrote:

Yea, someone knows what I'm talking about.  Can it be done and save many of us a Linux dual boot for when we want to work with audio?

Blitze, you wouldn't need a dual boot setup. Just compile your own kernel and make sure that you "modprobe realtime gid=92" in your rc.local.

This would work around the issues I described in the other post and have
things working out of the box. I just say it is no solution for the stock
kernel cuz of the possible combinations.

Just to let you know there is a bug(feature request) due to capabilities
module open.
http://bugs.archlinux.org/index.php?do=details&id=2354

The two possible "solutions" for stock kernel are the following:
1. ship realtime-lsm with some sort of a loader script that kicks capability
b4 realtime-lsm is loaded, yet I dunno where to write it to and how to
involve it. A possible hack might be to abuse an rc.d deamon script for
that. This would also require, that capability is loaded as standard in one
of the startup scripts. The deamon script kicks capability and loads
realtime on start and reverses that on stop. Nice side effect is that we
could determine the gid in a conf.d script.

2. negotiate the loading of modules on startup like here:

if [ -f /lib/modules/`uname -r`/extra/realtime.ko ]; then
  modprobe realtime gid=92
else
  modprobe capability
fi

A place for that could be rc.local, but this file should be left to the
user not to upstream modifications.

We would have to do somthing like that, if we like to have things in stock
kernel. I can't think of other ways to load the necessary modules. If
someone of you guys know, or if you know how to make vsftp load the
necessary modules (capability) on the fly lemme know it. Just note, vsftpd
is the troublemaker I know, others might be affected, too. The overall
problem is that realtime can't be loaded, once capability is loaded. So we
can make capabilities a module and force the loading of it on startup. But
then, it wouldn't make sense to have the realtime-lsm module cuz noone
ever can load it.

-neri

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#12 2005-06-16 11:56:45

Michel
Member
From: Belgium
Registered: 2004-07-31
Posts: 286

Re: Kernel26mm alternative?

Heya,

there may be a solution coming in the 2.6.12-kernel. It's a replacement for the realtime-module:

http://www.gossamer-threads.com/lists/m … ers/131634
http://www.steamballoon.com/wiki/Rlimits

It seems that jack is also getting/has support for it:
http://music.columbia.edu/pipermail/lin … 22957.html

greeetz,

Michel

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#13 2005-06-18 01:25:46

blitze
Member
From: Melbourne, Australia
Registered: 2004-03-19
Posts: 54

Re: Kernel26mm alternative?

Thankyou for the replies people.  Looks like there is an alternative being implemented which would make audio work under Linux a much better possibility.  Have to I might even consider staying with Linux for audio work but I am also keeping my eyes on YellowTabs Zeta as a possibility.

Now looking up Echo Gina 3G support in ALSA as I know there are drivers being developed for it under Haiku/Zeta and the Windows drivers have got to be better than the POS that ESI is providing for my Hoontech DSP24 C-Port.

God I regret the day I blew 12 hundred dollars on that POS.  6 years and crap support all the way.


Leave ones footprint not in the physical world but the in the world of the mind.

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#14 2005-06-18 09:25:47

neri
Forum Fellow
From: Victoria, Canada
Registered: 2003-05-04
Posts: 553

Re: Kernel26mm alternative?

Michel wrote:

Heya,

there may be a solution coming in the 2.6.12-kernel. It's a replacement for the realtime-module:

http://www.gossamer-threads.com/lists/m … ers/131634
http://www.steamballoon.com/wiki/Rlimits

It seems that jack is also getting/has support for it:
http://music.columbia.edu/pipermail/lin … 22957.html

Michel, I forgot to say thanks for that input. Maybe I find some time to play with it after LinuxTag and so there might be finally a way to bring it to the official repos. Do you know if the pam-patch (on the wiki it is for 0.77) is
in 0.79?

thanks,
  neri

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#15 2005-06-18 18:30:49

Michel
Member
From: Belgium
Registered: 2004-07-31
Posts: 286

Re: Kernel26mm alternative?

Heya neri,

no I haven't really an idea. I found this new method while browsing the mythtv-mailinglist I believe. I haven't really looked into it.

greetings,

Michel

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#16 2005-06-18 19:32:13

neri
Forum Fellow
From: Victoria, Canada
Registered: 2003-05-04
Posts: 553

Re: Kernel26mm alternative?

Michel wrote:

Heya neri,

no I haven't really an idea. I found this new method while browsing the mythtv-mailinglist I believe. I haven't really looked into it.

greetings,

Michel

But we really should look at it, cuz relatime as users r0xors. Maybe I can do some things durin LinuxTag.

-neri

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#17 2005-06-18 21:59:40

Gullible Jones
Member
Registered: 2004-12-29
Posts: 4,863

Re: Kernel26mm alternative?

2.6.12 is now out. Perhaps what you want is hidden somewhere in that massive changelist...

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#18 2005-06-18 22:54:32

neri
Forum Fellow
From: Victoria, Canada
Registered: 2003-05-04
Posts: 553

Re: Kernel26mm alternative?

Gullible Jones wrote:

2.6.12 is now out. Perhaps what you want is hidden somewhere in that massive changelist...

Thanks, yeah I saw it and the 1MB changelog, but we have too good weather over here for that tongue
rlimits was accepted in *.12.rc4 so it is in it. Unfortunately it requires some programs to be patched, pam eg. Though I dunno if it already happend in one of the latter versions. Fact is, rlimits need some kind of framwork of customized apps to work nicely. Hence testing of it will beginn. I really hoped for realtime-lsm ...

-neri

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#19 2005-07-03 08:34:54

neri
Forum Fellow
From: Victoria, Canada
Registered: 2003-05-04
Posts: 553

Re: Kernel26mm alternative?

Well,

I think I just hijack this thread for the relatime issues in general. Now, when
Realtime-lsm seems to be out of the game, we have to face the rlimits stuff-
needles to say that I'm not really happy with it after all the things I tried with
realtime-lsm.

Now the good news, rlimits is indeed working, yet I dun see the adavatage
over realtime-lsm. But waht does i take?
Get any 2.6.12 kernel from testing, self baked or whatever. You dun have to
mess with the config. But you need a patched PAM:

# $Id: PKGBUILD,v 1.14 2005/05/02 02:10:21 judd Exp $
# Maintainer: judd <jvinet@zeroflux.org>
pkgname=pam
pkgver=0.79
pkgrel=3
pkgdesc="PAM (Pluggable Authentication Modules) library"
url="http://www.kernel.org/pub/linux/libs/pam/"
depends=('glibc' 'filesystem' 'db' 'cracklib')
backup=(etc/security/{access.conf,group.conf,limits.conf,pam_env.conf,time.conf,pam_unix2.conf} etc/pam.d/other)
source=(http://www.kernel.org/pub/linux/libs/pam/pre/library/Linux-PAM-$pkgver.tar.bz2 
        ftp://ftp.suse.com/pub/people/kukuk/pam/pam_unix2/pam_unix2-1.25.tar.bz2 
        http://steamballoon.com/pam/pam-limits2.patch 
        other pam.patch pam-0.78.patch pam_unix2.patch)
md5sums=('0b89b73970c7d490ad9a13718b74d27b' '658b0f83a6163429d690cbb83c882356'
         '0dbe9d91b8e07889ab971cc6480dd6ce' '6e6c8719e5989d976a14610f340bd33a'
         'fd4446b11d330a7891b22665b1f37990' '26d4b54f5f6d91a8dbea2839fdc05532'
         'e9c26a06d21455301f799571a1b18ea4')

build() {
  cd $startdir/src/Linux-PAM-$pkgver
  patch -Np1 -i ../pam-0.78.patch || return 1
  patch -Np1 -i ../pam.patch || return 1
  patch -Np1 -i ../pam-limits2.patch || return 1
  sed -i "s|DICT_DIR_CANDIDATES=.*$|DICT_DIR_CANDIDATES="$startdir/pkg/usr/lib \\|" configure
  ./configure --sysconfdir=/etc --enable-fakeroot=$startdir/pkg
  make || return 1
  make INSTALL=/bin/install FAKEROOT=$startdir/pkg install
  install -D -m644 ../other $startdir/pkg/etc/pam.d/other
  cd $startdir/pkg/lib
  ln -s libpam.so.0.78 libpam.so.0
  ln -s libpam_misc.so.0.78 libpam_misc.so.0
  ln -s libpamc.so.0.78 libpamc.so.0
  # build pam_unix2 module
  cd $startdir/src/pam_unix2-1.25
  patch -Np1 -i ../pam_unix2.patch || return 1
  ./configure
  make || return 1
  make DESTDIR=$startdir/pkg install
  # some manpages get misplaced
  cd $startdir/pkg
  mv man/man8/* usr/man/man8/
  rm -rf man
}

edit your /etc/security/limits.conf and add the following lines:

*               -       rt_priority     0                            
*               -       nice            0                                       
@audio          -       rt_priority      65                           
@audio          -       nice             -10                            
@audio          -       memlock          40000

Note, this is a generic grant for the audio group. I think PAM can be used
to grant these levels on a per application base. If anyone has aquick hack
here, it would save me some time.

-neri

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#20 2006-09-09 18:50:44

phunni
Member
From: Bristol, UK
Registered: 2003-08-13
Posts: 768

Re: Kernel26mm alternative?

Looking at the latest PKGBUILD for pam, I'm assuming that this patch is no longer nexessary?  Since my limits.conf has been edited by the above PKGBUILD then I also assume that I don't actually need to do anything beyond being in audio to run jack as a user with the same results as if I ran it as root?

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