21 Jul
2007
21 Jul
'07
10:03 a.m.
Hi
I trying out ubuntu with ubuntustudio kernel. In debian I always set the
priority of the IRQ's using
chrt -f -p 85 `pidof "IRQ 8"`
However that doesn't work in ubuntu. The reason is that there seems to
be no process named "IRQ 8":
atte@ajstrup:~$ ps aux | grep -i IRQ
root 3 0.0 0.0 0 0 ? SN 13:43 0:00
[ksoftirqd/0]
atte 6274 0.0 0.0 2884 772 pts/0 R+ 13:51 0:00 grep -i
irq
Whereas on debian I would get:
atte@ajstrup:~$ ps aux | grep IRQ
root 18 0.2 0.0 0 0 ? S< 13:34 0:00 [IRQ 9]
root 261 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 4]
root 286 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
12]
root 300 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 1]
root 608 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
11]
root 761 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
14]
root 787 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
15]
root 1592 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 8]
root 1593 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 7]
root 1683 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
10]
atte 4672 0.0 0.0 2848 704 pts/1 R+ 13:41 0:00 grep
IRQ
I suspect it has something to do with "ksoftirqd" which according to the
man page seems to be a daemon handling irqs.
http://tapas.affenbande.org/wordpress/?page_id=40 also doesn't seem to
take ksoftirqd into account.
So my question is: How do I set the priorities in ubuntu? Is it
possible/clever/stupid to get rid og ksoftirqd and get things working
the way I'm used to under debian, and if so how?
--
peace, love & harmony
Atte
http://atte.dk | http://myspace.com/attejensen
http://anagrammer.dk | http://atte.dk/compositions
21 Jul
21 Jul
10:25 a.m.
On Sat, Jul 21, 2007 at 02:03:19PM +0200, Atte Andr? Jensen wrote:
Whereas on debian I would get:
atte@ajstrup:~$ ps aux | grep IRQ
root 18 0.2 0.0 0 0 ? S< 13:34 0:00 [IRQ 9]
Which kernel version is this? On Debian, I get ksoftirqd as well, one
per processor core. ksoftirqd is part of the 2.6 kernel series. I
imagine you're still using a 2.4 kernel on your Debian system, or the
kernel is configured and built differently to mine.
It may be possible to rebuild the Ubuntu kernel you are using to match
what you are used to, but I don't know if that will get you what you
want. I've never tried setting real-time priority on kernel threads
like that, and I don't know if it would achieve anything. I trust it
did for you?
--
James Cameron mailto:quozl@us.netrek.org http://quozl.netrek.org/
2:35 p.m.
On Sat, 2007-07-21 at 22:26 +1000, James Cameron wrote:
On Sat, Jul 21, 2007 at 02:03:19PM +0200, Atte Andr?
Jensen wrote:
Homemade (with mingo rt-patch) 2.6.18-rt7
2.6.20-16-lowlatency
Whereas on debian I would get:
atte@ajstrup:~$ ps aux | grep IRQ
root 18 0.2 0.0 0 0 ? S< 13:34 0:00 [IRQ 9]
Which kernel version is this? On Debian, I get ksoftirqd as well, one
per processor core. ksoftirqd is part of the 2.6 kernel series. I
imagine you're still using a 2.4 kernel on your Debian system,
Nope...
or the
kernel is configured and built differently to mine.
Might be...
It may be possible to rebuild the Ubuntu kernel you
are using to match
what you are used to, but I don't know if that will get you what you
want.
I grabbed a vanilla 2.6.22.1 and applied the latest patch and quick
testing seems to suggest that the system is running at least at well as
under debian:
atte@ajstrup:~$ uname -r
2.6.22.1-rt4
atte@ajstrup:~$ ps aux | grep IRQ
root 36 0.0 0.0 0 0 ? S< 18:15 0:00 [IRQ-9]
root 268 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-4]
root 292 0.0 0.0 0 0 ? S< 18:16 0:00
[IRQ-12]
root 293 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-1]
root 1108 0.0 0.0 0 0 ? S< 18:16 0:00
[IRQ-14]
root 1139 0.0 0.0 0 0 ? S< 18:16 0:00
[IRQ-15]
root 1140 0.2 0.0 0 0 ? S< 18:16 0:02
[IRQ-11]
root 1936 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-8]
root 2025 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-7]
root 2103 0.3 0.0 0 0 ? S< 18:16 0:03
[IRQ-10]
root 3432 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-3]
atte 4674 0.0 0.0 2888 772 pts/2 R+ 18:33 0:00 grep
IRQ
I've never tried setting real-time priority on
kernel threads
like that, and I don't know if it would achieve anything. I trust it
did for you?
Alot!
Bottom line: It seems it's still necessary to roll your own kernel to
get optimal realtime performance under ubuntu :-(
--
peace, love & harmony
Atte
http://atte.dk | http://myspace.com/attejensen
http://anagrammer.dk | http://atte.dk/compositions
9:40 p.m.
On Saturday 21 July 2007, Atte André Jensen wrote:
The lowlatency kernel of ubuntu is not a realtime kernel. And for your home
made kernel, please let us see your .config
e.g.
~$ grep PREEMPT /boot/config-$(uname -r)
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
# CONFIG_PREEMPT_DESKTOP is not set
CONFIG_PREEMPT_RT=y
^^^^^^^^^^^^^^^
CONFIG_PREEMPT=y
CONFIG_PREEMPT_SOFTIRQS=y
CONFIG_PREEMPT_HARDIRQS=y
CONFIG_PREEMPT_BKL=y
CONFIG_PREEMPT_RCU=y
# CONFIG_DEBUG_PREEMPT is not set
# CONFIG_CRITICAL_PREEMPT_TIMING is not set
I underlined the relevant line there
--
Palimm Palimm!
http://tapas.affenbande.org
Which kernel
version is this?
Homemade (with mingo rt-patch) 2.6.18-rt7
2.6.20-16-lowlatency On Debian, I get ksoftirqd as well, one
per processor core. ksoftirqd is part of the 2.6 kernel series. I
imagine you're still using a 2.4 kernel on your Debian system,
Nope...
or the
kernel is configured and built differently to mine.
Might be...
It may be possible to rebuild the Ubuntu kernel
you are using to match
what you are used to, but I don't know if that will get you what you
want.
I grabbed a vanilla 2.6.22.1 and applied the latest patch and quick
testing seems to suggest that the system is running at least at well as
under debian:
atte@ajstrup:~$ uname -r
2.6.22.1-rt4
atte@ajstrup:~$ ps aux | grep IRQ
root 36 0.0 0.0 0 0 ? S< 18:15 0:00 [IRQ-9]
root 268 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-4]
root 292 0.0 0.0 0 0 ? S< 18:16 0:00
[IRQ-12]
root 293 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-1]
root 1108 0.0 0.0 0 0 ? S< 18:16 0:00
[IRQ-14]
root 1139 0.0 0.0 0 0 ? S< 18:16 0:00
[IRQ-15]
root 1140 0.2 0.0 0 0 ? S< 18:16 0:02
[IRQ-11]
root 1936 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-8]
root 2025 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-7]
root 2103 0.3 0.0 0 0 ? S< 18:16 0:03
[IRQ-10]
root 3432 0.0 0.0 0 0 ? S< 18:16 0:00 [IRQ-3]
atte 4674 0.0 0.0 2888 772 pts/2 R+ 18:33 0:00 grep
IRQ
I've never tried setting real-time priority
on kernel threads
like that, and I don't know if it would achieve anything. I trust it
did for you?
Alot!
Bottom line: It seems it's still necessary to roll your own kernel to
get optimal realtime performance under ubuntu :-(
22 Jul
22 Jul
5:05 a.m.
On Sun, 2007-07-22 at 01:40 +0200, Florian Schmidt wrote:
The lowlatency kernel of ubuntu is not a realtime
kernel. And for your home
made kernel, please let us see your .config
Thanks for your interest, but I consider this issue solved as suggested
by one of my post in the tread.
Anyways...
e.g.
~$ grep PREEMPT /boot/config-$(uname -r)
Ubuntu:
atte@ajstrup:~$ grep PREEMPT /boot/config-2.6.22.1-rt4
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
# CONFIG_PREEMPT_DESKTOP is not set
CONFIG_PREEMPT_RT=y
CONFIG_PREEMPT=y
CONFIG_PREEMPT_SOFTIRQS=y
CONFIG_PREEMPT_HARDIRQS=y
CONFIG_PREEMPT_BKL=y
CONFIG_PREEMPT_RCU=y
# CONFIG_CRITICAL_PREEMPT_TIMING is not set
Debian:
atte@ajstrup:~$ grep PREEMPT /mnt/debian/boot/config-2.6.18-rt7
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
# CONFIG_PREEMPT_DESKTOP is not set
CONFIG_PREEMPT_RT=y
CONFIG_PREEMPT=y
CONFIG_PREEMPT_SOFTIRQS=y
CONFIG_PREEMPT_HARDIRQS=y
CONFIG_PREEMPT_BKL=y
CONFIG_PREEMPT_RCU=y
# CONFIG_CRITICAL_PREEMPT_TIMING is not set
--
peace, love & harmony
Atte
http://atte.dk | http://myspace.com/attejensen
http://anagrammer.dk | http://atte.dk/compositions
21 Jul
21 Jul
10:27 a.m.
On Sa, 21.07.07 14:03 Atte André Jensen <atte.jensen(a)gmail.com> wrote:
Hi
I trying out ubuntu with ubuntustudio kernel. In debian I always set
the priority of the IRQ's using
chrt -f -p 85 `pidof "IRQ 8"`
However that doesn't work in ubuntu. The reason is that there seems to
be no process named "IRQ 8":
I only get processes for IRQ's on -rt patched kernels
Maybe ubuntustudio uses a standard patched-to-death ubuntu kernel with
hz 1000 and LLD preempt?
atte@ajstrup:~$ ps aux | grep -i IRQ
root 3 0.0 0.0 0 0 ? SN 13:43 0:00
[ksoftirqd/0]
atte 6274 0.0 0.0 2884 772 pts/0 R+ 13:51 0:00 grep
-i irq
Whereas on debian I would get:
atte@ajstrup:~$ ps aux | grep IRQ
root 18 0.2 0.0 0 0 ? S< 13:34 0:00 [IRQ
9] root 261 0.0 0.0 0 0 ? S< 13:34 0:00
[IRQ 4] root 286 0.0 0.0 0 0 ? S< 13:34
0:00 [IRQ 12]
root 300 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
1] root 608 0.0 0.0 0 0 ? S< 13:34 0:00
[IRQ 11]
root 761 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
14]
root 787 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
15]
root 1592 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
8] root 1593 0.0 0.0 0 0 ? S< 13:34 0:00
[IRQ 7] root 1683 0.0 0.0 0 0 ? S< 13:34
0:00 [IRQ 10]
atte 4672 0.0 0.0 2848 704 pts/1 R+ 13:41 0:00 grep
IRQ
I suspect it has something to do with "ksoftirqd" which according to
the man page seems to be a daemon handling irqs.
http://tapas.affenbande.org/wordpress/?page_id=40 also doesn't seem to
take ksoftirqd into account.
So my question is: How do I set the priorities in ubuntu? Is it
possible/clever/stupid to get rid og ksoftirqd and get things working
the way I'm used to under debian, and if so how?
--
peace, love & harmony
Atte
http://atte.dk | http://myspace.com/attejensen
http://anagrammer.dk | http://atte.dk/compositions
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user
12:04 p.m.
Atte André Jensen a écrit :
Hi
I trying out ubuntu with ubuntustudio kernel. In debian I always set the
priority of the IRQ's using
chrt -f -p 85 `pidof "IRQ 8"`
However that doesn't work in ubuntu. The reason is that there seems to
be no process named "IRQ 8":
atte@ajstrup:~$ ps aux | grep -i IRQ
root 3 0.0 0.0 0 0 ? SN 13:43 0:00
[ksoftirqd/0]
atte 6274 0.0 0.0 2884 772 pts/0 R+ 13:51 0:00 grep -i
irq
Hi,
Your ubuntu kernel doesn't support this feature, to be sure try to look
at /proc/config.gz
zcat /proc/config.gz | grep PREEMPT
You must have something like this :
CONFIG_PREEMPT_HARDIRQS=y
It appears that the default kernel used by Ubuntu studio
(linux-image-lowlatency) is not patched against the Ingo's RT patch
(required to do what you want)
http://www.mail-archive.com/debian-multimedia@lists.debian.org/msg01756.html
The RT kernel package seems to be linux-image-2.6.21-1-multimedia-486
<http://apt.64studio.com/64studio/testing/pool/main/l/linux-2.6/linux-image-2.6.21-1-multimedia-486_2.6.21-2_i386.deb>
David C.
12:48 p.m.
Please forget all the package stuff in my last post they are not related
to your distribution I was confused by all those *studio distribution
sorry :)
Please refer to this HOWTO dedicated to your distribution :
https://help.ubuntu.com/community/UbuntuStudio/DapperPreparation
and specifically for your IRQ problem to
https://help.ubuntu.com/community/HowToVanillaKernelWithRealtimePreemption
You will have to compile the kernel yourself so unless you really need
extreme low latency I will suggest to keep your current kernel.
David C.
2:39 p.m.
On Saturday 21 July 2007 10:03:24 David Causse wrote:
Atte André Jensen a écrit :
it's probably, actually, because there's a dash in the proc name. IRQ-8,
etc...
james
Hi
I trying out ubuntu with ubuntustudio kernel. In debian I always set the
priority of the IRQ's using
chrt -f -p 85 `pidof "IRQ 8"`
However that doesn't work in ubuntu. The reason is that there seems to
be no process named "IRQ 8":
atte@ajstrup:~$ ps aux | grep -i IRQ
root 3 0.0 0.0 0 0 ? SN 13:43 0:00
[ksoftirqd/0]
atte 6274 0.0 0.0 2884 772 pts/0 R+ 13:51 0:00 grep -i
irq
Hi,
Your ubuntu kernel doesn't support this feature, to be sure try to look
at /proc/config.gz
zcat /proc/config.gz | grep PREEMPT
You must have something like this :
CONFIG_PREEMPT_HARDIRQS=y
It appears that the default kernel used by Ubuntu studio
(linux-image-lowlatency) is not patched against the Ingo's RT patch
(required to do what you want)
http://www.mail-archive.com/debian-multimedia@lists.debian.org/msg01756.htm
l The RT kernel package seems to be linux-image-2.6.21-1-multimedia-486
<http://apt.64studio.com/64studio/testing/pool/main/l/linux-2.6/linux-image
-2.6.21-1-multimedia-486_2.6.21-2_i386.deb>
David C.
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user
2:47 p.m.
On Sat, 2007-07-21 at 12:39 -0400, james wrote:
it's probably, actually, because there's a
dash in the proc name. IRQ-8,
etc...
Nope. That did bite me before, though. And "ps aux | grep IRQ" would
catch both...
--
peace, love & harmony
Atte
http://atte.dk | http://myspace.com/attejensen
http://anagrammer.dk | http://atte.dk/compositions
6:45 p.m.
On Saturday 21 July 2007 12:47:41 Atte André Jensen wrote:
On Sat, 2007-07-21 at 12:39 -0400, james wrote:
ok how about noapic boot option?
james
it's probably, actually, because there's
a dash in the proc name. IRQ-8,
etc...
Nope. That did bite me before, though. And "ps aux | grep IRQ" would
catch both...
7:08 p.m.
On Saturday 21 July 2007 12:47:41 Atte André Jensen wrote:
On Sat, 2007-07-21 at 12:39 -0400, james wrote:
oh, btw, the realtime ingo patched kernel for ubuntustudio is here:
https://wiki.ubuntu.com/RealTime
it's probably, actually, because there's
a dash in the proc name. IRQ-8,
etc...
Nope. That did bite me before, though. And "ps aux | grep IRQ" would
catch both...
9:24 p.m.
On Sat, 2007-07-21 at 17:08 -0400, james wrote:
oh, btw, the realtime ingo patched kernel for
ubuntustudio is here:
https://wiki.ubuntu.com/RealTime
Those are what I already have. I don't know if they are patched with
ingo's patch, but this is exactly the kernel that exhibited the problem
mentioned in the original post. You did read that, right?
--
peace, love & harmony
Atte
http://atte.dk | http://myspace.com/attejensen
http://anagrammer.dk | http://atte.dk/compositions
9:36 p.m.
On Saturday 21 July 2007, Atte André Jensen wrote:
Hi
I trying out ubuntu with ubuntustudio kernel. In debian I always set the
priority of the IRQ's using
chrt -f -p 85 `pidof "IRQ 8"`
However that doesn't work in ubuntu. The reason is that there seems to
be no process named "IRQ 8":
atte@ajstrup:~$ ps aux | grep -i IRQ
root 3 0.0 0.0 0 0 ? SN 13:43 0:00
[ksoftirqd/0]
atte 6274 0.0 0.0 2884 772 pts/0 R+ 13:51 0:00 grep -i
irq
Whereas on debian I would get:
atte@ajstrup:~$ ps aux | grep IRQ
root 18 0.2 0.0 0 0 ? S< 13:34 0:00 [IRQ 9]
root 261 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 4]
root 286 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
12]
root 300 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 1]
root 608 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
11]
root 761 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
14]
root 787 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
15]
root 1592 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 8]
root 1593 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ 7]
root 1683 0.0 0.0 0 0 ? S< 13:34 0:00 [IRQ
10]
atte 4672 0.0 0.0 2848 704 pts/1 R+ 13:41 0:00 grep
IRQ
I suspect it has something to do with "ksoftirqd" which according to the
man page seems to be a daemon handling irqs.
http://tapas.affenbande.org/wordpress/?page_id=40 also doesn't seem to
take ksoftirqd into account.
So my question is: How do I set the priorities in ubuntu? Is it
possible/clever/stupid to get rid og ksoftirqd and get things working
the way I'm used to under debian, and if so how?
No, ksoftirq shouldn't have anything to do with it.. HEre's what the output of
that is on my system:
~$ ps aux|grep IRQ
root 41 0.0 0.0 0 0 ? S< Jul21 0:00 [IRQ-9]
root 775 0.0 0.0 0 0 ? S< Jul21 0:00 [IRQ-8]
root 812 0.0 0.0 0 0 ? S< Jul21 0:09 [IRQ-12]
root 813 0.0 0.0 0 0 ? S< Jul21 0:00 [IRQ-1]
root 2032 0.0 0.0 0 0 ? S< Jul21 0:00 [IRQ-16]
root 2110 0.0 0.0 0 0 ? S< Jul21 0:00 [IRQ-17]
root 2152 0.0 0.0 0 0 ? S< Jul21 0:03 [IRQ-14]
root 2192 0.0 0.0 0 0 ? S< Jul21 0:02 [IRQ-15]
root 2745 0.4 0.0 0 0 ? S< Jul21 3:42 [IRQ-18]
root 3629 0.0 0.0 0 0 ? S< Jul21 0:00 [IRQ-7]
root 3785 0.1 0.0 0 0 ? S< Jul21 0:55 [IRQ-19]
tapas 14252 0.0 0.0 2884 752 pts/1 R+ 01:35 0:00 grep IRQ
~$ uname -a
Linux balabala 2.6.20-16-realtime #2 SMP PREEMPT Fri Jun 15 04:43:25 CEST 2007
i686 GNU/Linux
Let's see your uname -a output please..
Flo
--
Palimm Palimm!
http://tapas.affenbande.org
6528
days inactive
6529
days old
linux-audio-user@lists.linuxaudio.org
13 comments
6 participants
participants (6)
-
Atte André Jensen -
David Causse -
Florian Schmidt -
james -
James Cameron -
Thomas Kuther