26 Nov
2008
26 Nov
'08
7:07 p.m.
Hi,
There are some rumors about the lack of need for an RT patch with new
kernel, after 2.6.26.xx for making (realtime) music on GNU/Linux.
What is true about this?
Thanks in advance,
\r
26 Nov
26 Nov
7:45 p.m.
On Thu, 2008-11-27 at 00:07 +0100, Grammostola Rosea wrote:
Hi,
There are some rumors about the lack of need for an RT patch with new
kernel, after 2.6.26.xx for making (realtime) music on GNU/Linux.
What is true about this?
And were did you hear those "rumors"? Source? URL? etc?
As usual, it depends. What does "realtime" mean to you?
Very low latencies?[*] Then you _will_ need the realtime preemption
patches or you will have to live with xruns. Not so low latencies?
Vanilla kernels > 2.6.26 will probably work just fine.
It also depends on what hardware mixture you have on your computer and
how it is (or is not) tuned.
A caveat is that the realtime preemption patches for 2.6.26.x don't seem
to work too well (midi problems when used with external controllers).
And for 2.6.27.x there is nothing even usable yet (last time I looked).
The latest "stable" preemption patches are for 2.6.24.x, which is
regretfully now too old for many hardware configurations (and even for
some software, like the newer X servers).
In both cases you will need a working Jack and you will need to run it
with realtime priority (which has nothing to do with the realtime
preemption patches).
Hmmm, so am I now perpetuating the rumor? :-)
-- Fernando
[*] 5-10 mSecs? There is no hard boundary...
27 Nov
27 Nov
1:28 a.m.
On Wed, Nov 26, 2008 at 03:45:45PM -0800, Fernando Lopez-Lezcano wrote:
In both cases you will need a working Jack and you will need to run it
with realtime priority (which has nothing to do with the realtime
preemption patches).
the rumor i am concerned about, is, that you need an RT kernel to run
jackd.
can people stop saying this please ?
--
torben Hohn
1:56 a.m.
i haven't had any real problems with 2.6.26 RT patches, but i don't
use my midi gear in linux (waiting for ardour 3 branch to mature a bit
more first). is there any reason the 2.6.26 patch hasn't been ported
forward to 2.6.27? are the changes that prominent that the patch is
too difficult to port? i remember the last few releases (24, 25 and
26) didn't take too long before a (albeit preliminary) patch was
available, but i have found nothing at all for 27. i'd like to update
this machine to intrepid but i want to make sure i'm not going
backwards in terms of rt support (i know i can use the older kernel
i'm using now, but it kinda defeats the purpose of upgrading then). i
noticed there is a 2.6.27-rt package in intrepid actually, what is
this if the rt patches aren't available yet?
sorry to ramble
porl
2008/11/27 <torbenh(a)gmx.de>de>:
On Wed, Nov 26, 2008 at 03:45:45PM -0800, Fernando
Lopez-Lezcano wrote:
--
i am kurious oranj!
In both cases you will need a working Jack and you will need to run it
with realtime priority (which has nothing to do with the realtime
preemption patches).
the rumor i am concerned about, is, that you need an RT kernel to run
jackd.
can people stop saying this please ?
--
torben Hohn
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
2:16 a.m.
there is a patch for 2.6.27 avaluable here:
http://opensource1.windriver.com/gitweb/gitweb.cgi?p=people/paulg/rt/patches
I dont have test them for now I stay with 2.6.25.9-rt7
regards hermann
Am Donnerstag, den 27.11.2008, 16:56 +1100 schrieb porl sheean:
i haven't had any real problems with 2.6.26 RT
patches, but i don't
use my midi gear in linux (waiting for ardour 3 branch to mature a bit
more first). is there any reason the 2.6.26 patch hasn't been ported
forward to 2.6.27? are the changes that prominent that the patch is
too difficult to port? i remember the last few releases (24, 25 and
26) didn't take too long before a (albeit preliminary) patch was
available, but i have found nothing at all for 27. i'd like to update
this machine to intrepid but i want to make sure i'm not going
backwards in terms of rt support (i know i can use the older kernel
i'm using now, but it kinda defeats the purpose of upgrading then). i
noticed there is a 2.6.27-rt package in intrepid actually, what is
this if the rt patches aren't available yet?
sorry to ramble
porl
2008/11/27 <torbenh(a)gmx.de>de>:
On Wed, Nov 26, 2008 at 03:45:45PM -0800,
Fernando Lopez-Lezcano wrote:
In both cases you will need a working Jack and you will need to run it
with realtime priority (which has nothing to do with the realtime
preemption patches).
the rumor i am concerned about, is, that you need an RT kernel to run
jackd.
can people stop saying this please ?
--
torben Hohn
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
8:18 a.m.
thanks, i'll check it out when i get a chance :)
porl
2008/11/27 hermann meyer <brummer-(a)web.de>de>:
there is a patch for 2.6.27 avaluable here:
http://opensource1.windriver.com/gitweb/gitweb.cgi?p=people/paulg/rt/patches
I dont have test them for now I stay with 2.6.25.9-rt7
regards hermann
Am Donnerstag, den 27.11.2008, 16:56 +1100 schrieb porl sheean:
--
i am kurious oranj!
i haven't had any real problems with 2.6.26
RT patches, but i don't
use my midi gear in linux (waiting for ardour 3 branch to mature a bit
more first). is there any reason the 2.6.26 patch hasn't been ported
forward to 2.6.27? are the changes that prominent that the patch is
too difficult to port? i remember the last few releases (24, 25 and
26) didn't take too long before a (albeit preliminary) patch was
available, but i have found nothing at all for 27. i'd like to update
this machine to intrepid but i want to make sure i'm not going
backwards in terms of rt support (i know i can use the older kernel
i'm using now, but it kinda defeats the purpose of upgrading then). i
noticed there is a 2.6.27-rt package in intrepid actually, what is
this if the rt patches aren't available yet?
sorry to ramble
porl
2008/11/27 <torbenh(a)gmx.de>de>:
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
On Wed, Nov 26, 2008 at 03:45:45PM -0800,
Fernando Lopez-Lezcano wrote:
In both cases you will need a working Jack and you will need to run it
with realtime priority (which has nothing to do with the realtime
preemption patches).
the rumor i am concerned about, is, that you need an RT kernel to run
jackd.
can people stop saying this please ?
--
torben Hohn
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
6:16 p.m.
On Thu, 2008-11-27 at 07:21 +0100, hermann meyer wrote:
there is a patch for 2.6.27 avaluable here:
http://opensource1.windriver.com/gitweb/gitweb.cgi?p=people/paulg/rt/patches
I dont have test them for now I stay with 2.6.25.9-rt7
I tried that one a couple of weeks ago and I never got a bootable kernel
out of it (I don't see any substantial differences in the newer version,
just some fixes to nrpages that I had to apply separately to get it to
build).
-- Fernando
Am Donnerstag, den 27.11.2008, 16:56 +1100 schrieb
porl sheean:
i haven't had any real problems with 2.6.26
RT patches, but i don't
use my midi gear in linux (waiting for ardour 3 branch to mature a bit
more first). is there any reason the 2.6.26 patch hasn't been ported
forward to 2.6.27? are the changes that prominent that the patch is
too difficult to port? i remember the last few releases (24, 25 and
26) didn't take too long before a (albeit preliminary) patch was
available, but i have found nothing at all for 27. i'd like to update
this machine to intrepid but i want to make sure i'm not going
backwards in terms of rt support (i know i can use the older kernel
i'm using now, but it kinda defeats the purpose of upgrading then). i
noticed there is a 2.6.27-rt package in intrepid actually, what is
this if the rt patches aren't available yet?
sorry to ramble
porl
2008/11/27 <torbenh(a)gmx.de>de>:
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user On Wed, Nov 26, 2008 at 03:45:45PM -0800,
Fernando Lopez-Lezcano wrote:
In both cases you will need a working Jack and you will need to run it
with realtime priority (which has nothing to do with the realtime
preemption patches).
the rumor i am concerned about, is, that you need an RT kernel to run
jackd.
can people stop saying this please ?
--
torben Hohn
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
1:46 p.m.
Fernando Lopez-Lezcano <nando(a)ccrma.Stanford.EDU> writes:
A caveat is that the realtime preemption patches for
2.6.26.x don't
seem to work too well (midi problems when used with external
controllers).
Could you be more specific? It sounds like the problem I'm currently
seeing with 2.6.26.6-rt11.
I had problems with earlier RT kernels such as 2.6.25.8-rt7 occasionally
locking up on my machine (in a way that das_watchdog wouldn't recover
from but the kernel software watchdog would detect), but 2.6.26.6-rt11
has been running happily for three weeks now.
The downside is that the MIDI port on my Audiophile 2496 doesn't work:
trying to open /dev/snd/midiC0D0 always returns EBUSY, even when nothing
else has it open, and events from it don't seem to make it into the
sequencer. In addition, the snd_ice1712 module seems to have a reference
count of 2 even when nothing has any of the sound devices open...
--
Adam Sampson <ats(a)offog.org> <http://offog.org/>
5:23 p.m.
On Thu, 2008-11-27 at 17:46 +0000, Adam Sampson wrote:
Fernando Lopez-Lezcano
<nando(a)ccrma.Stanford.EDU> writes:
I have seen it lock up hard. Not frequently but it happens.
A caveat is that the realtime preemption patches
for 2.6.26.x don't
seem to work too well (midi problems when used with external
controllers).
Could you be more specific? It sounds like the problem I'm currently
seeing with 2.6.26.6-rt11.
I had problems with earlier RT kernels such as 2.6.25.8-rt7 occasionally
locking up on my machine (in a way that das_watchdog wouldn't recover
from but the kernel software watchdog would detect), but 2.6.26.6-rt11
has been running happily for three weeks now. The downside is that the MIDI port on my Audiophile
2496 doesn't work:
trying to open /dev/snd/midiC0D0 always returns EBUSY, even when nothing
else has it open, and events from it don't seem to make it into the
sequencer. In addition, the snd_ice1712 module seems to have a reference
count of 2 even when nothing has any of the sound devices open...
What I'm seeing is that the alsa sequencer does not work when there are
rawmidi ports involved. That is, it works as long as the sequencer ports
are software, not hardware.
And rawmidi works fine by itself. But as soon as you try to use an
external device through the alsa sequencer the client hangs. And it
hangs hard, you need a reboot to get rid of it (the rest of the machine
keeps running just fine - this appears to be a deadlock inside the
sequencer code).
I posted a long thread on lkml, with printk information and so on, and
there were some suggestions (one made midi input work) but no kernel
guru stepped up to fix the problem or request more information. I latter
discovered that the problem was not solved, the internal timer of the
alsa sequencer seem to be broken. I have not had time to repost a
message to lkml and try to debug this.
-- Fernando
5914
days inactive
5915
days old
linux-audio-user@lists.linuxaudio.org
8 comments
6 participants
participants (6)
-
Adam Sampson -
Fernando Lopez-Lezcano -
Grammostola Rosea -
hermann meyer -
porl sheean -
torbenh＠gmx.de