linuxaudio.org

On Sun, 2010-07-11 at 18:07 +0200, Robin Gareus wrote:

quoted text
> The whole output of 'ps -eo...' will be tooooooo long. Just have a look

> and check for high priority processes that are different on both systems.

> If you have rtirq installed: '/etc/init.d/rtirq status' will show the

> same list but only display processes with RTPRIO set.

>

> Oh and I missed that the Ubuntu's 2.6.32.XX is actually not a rt-preemt

> kernel. many thanks to Arnout to spot that.

>

> If there's still a difference between SuSe & Ubuntu using the identical

> kernel, with no significant high-priority processes: please post the

> version of the alsa-libs for both systems.

>

> Not sure if it has been mentioned before, but you should set your

> soundcard's IRQ handler priority to sth "high" (eg 90) and use '-P 89'

> with alsa-midi-latency-test.

> With the default of "-P 99" the kernel will always end up inverting

> priorities to run it (the overhead for doing so is low but it may still

> be relevant).

>

>

> Thanks for being persistent on the Midi Jitter issue. Some of that info

> is bound to come in handy..

>

> ciao,

> robin

When I booted Ubuntustudio I didn't get this mail, so here is what I did

before I read your mail.
The blame is on Ubuntustudio.
Ubuntustudio by default isn't able to do rt! Changing the defaults seems

to be not that easy!

What an odd distro!
I did check the md5sum for the Ubuntustudio ISO and K3b did verify the

burned DVD, everything was ok.
########################################################################

openSUSE 11.2

########################################################################
suse11-2:/media/ubuntu_s_home/spinymouse/Desktop # cat /proc/interrupts

quoted text
> suse_proc_irqs.txt

suse11-2:/media/ubuntu_s_home/spinymouse/Desktop # ps ax | wc -l

186

suse11-2:/media/ubuntu_s_home/spinymouse/Desktop # ps -eo

pid,class,rtprio,ni,pri,pcpu,stat,comm --sort -rtprio >

suse_job_prio.txt

########################################################################

Ubuntu Studio 10.04

########################################################################
1.
For Ubuntu Studio by default frequency scaling isn't performance.

Fortunately 'cpufreq-selector -g performance' does the job, but it must

be finished by Ctrl + C.
2.
If I try to boot kernel 2.6.31-11-rt or kernel 2.6.31-10-rt from the

repositories I get

'mount: mounting none on /dev failed: No such device.' Regading to the

web this might be, because of CONFIG_DEVTMPFS.
3.
PID CLS RTPRIO  NI PRI %CPU STAT COMMAND

    3 FF      99   - 139  0.0 S<   migration/0

   13 FF      99   - 139  0.0 S<   posixcputmr/0

   14 FF      99   - 139  0.0 S<   watchdog/0

   16 FF      99   - 139  0.0 S<   migration/1

   17 FF      99   - 139  0.0 S<   posixcputmr/1

   27 FF      99   - 139  0.0 S<   watchdog/1

   83 FF      90   - 130  0.0 S<   irq/8-rtc0

  655 FF      85   - 125  0.0 S<   irq/21-ICE1712

  653 FF      84   - 124  0.0 S<   irq/20-ICE1712
for Suse vs
PID CLS RTPRIO  NI PRI %CPU STAT COMMAND

    3 FF      99   - 139  0.0 S    migration/0

    5 FF      99   - 139  0.0 S    watchdog/0

    6 FF      99   - 139  0.0 S    migration/1

    8 FF      99   - 139  0.0 S    watchdog/1

    1 TS       -   [...]
for Ubuntu.
root@ubuntu:~# hwinfo --cpu

  Model: 15.107.2 "AMD Athlon(tm) X2 Dual Core Processor BE-2350"

  Clock: 1000 MHz

root@ubuntu:~# cpufreq-selector -g performance
^C

root@ubuntu:~# hwinfo --cpu

  Model: 15.107.2 "AMD Athlon(tm) X2 Dual Core Processor BE-2350"

  Clock: 2100 MHz

root@ubuntu:~# ps ax | wc -l

152

root@ubuntu:~# cd /home/spinymouse/Desktop

root@ubuntu:/home/spinymouse/Desktop# cat /proc/interrupts >

ubuntustudio_proc_irqs.txt

root@ubuntu:/home/spinymouse/Desktop# ps ax | wc -l

151

root@ubuntu:/home/spinymouse/Desktop# ps ax | wc -l

151

root@ubuntu:/home/spinymouse/Desktop# ps -eo

pid,class,rtprio,ni,pri,pcpu,stat,comm --sort -rtprio >

ubuntustudio_job_prio.txt

root@ubuntu:/home/spinymouse/Desktop# cat /boot/grub/grub.cfg

menuentry 'Ubuntu, with Linux 2.6.32-23-preempt' --class ubuntu --class

gnu-linux --class gnu --class os {

	recordfail

	insmod ext2

	set root='(hd1,11)'

	search --no-floppy --fs-uuid --set 54b5bb8c-356a-4268-8592-e76aac7941a8

	linux	/boot/vmlinuz-2.6.32-23-preempt

root=UUID=54b5bb8c-356a-4268-8592-e76aac7941a8 ro   quiet splash

	initrd	/boot/initrd.img-2.6.32-23-preempt

}

menuentry 'Ubuntu, with Linux 2.6.32-21-preempt' --class ubuntu --class

gnu-linux --class gnu --class os {

	recordfail

	insmod ext2

	set root='(hd1,11)'

	search --no-floppy --fs-uuid --set 54b5bb8c-356a-4268-8592-e76aac7941a8

	linux	/boot/vmlinuz-2.6.32-21-preempt

root=UUID=54b5bb8c-356a-4268-8592-e76aac7941a8 ro   quiet splash

	initrd	/boot/initrd.img-2.6.32-21-preempt

}

menuentry 'Ubuntu, with Linux 2.6.31-11-rt' --class ubuntu --class

gnu-linux --class gnu --class os {

	recordfail

	insmod ext2

	set root='(hd1,11)'

	search --no-floppy --fs-uuid --set 54b5bb8c-356a-4268-8592-e76aac7941a8

	linux	/boot/vmlinuz-2.6.31-11-rt

root=UUID=54b5bb8c-356a-4268-8592-e76aac7941a8 ro   quiet splash

	initrd	/boot/initrd.img-2.6.31-11-rt

}

menuentry 'Ubuntu, with Linux 2.6.31-10-rt' --class ubuntu --class

gnu-linux --class gnu --class os {

	recordfail

	insmod ext2

	set root='(hd1,11)'

	search --no-floppy --fs-uuid --set 54b5bb8c-356a-4268-8592-e76aac7941a8

	linux	/boot/vmlinuz-2.6.31-10-rt

root=UUID=54b5bb8c-356a-4268-8592-e76aac7941a8 ro   quiet splash

	initrd	/boot/initrd.img-2.6.31-10-rt

root@ubuntu:/home/spinymouse/Desktop# uname -a

Linux ubuntu 2.6.32-23-preempt #37-Ubuntu SMP PREEMPT Fri Jun 11

10:19:07 UTC 2010 x86_64 GNU/Linux

root@ubuntu:/home/spinymouse/Desktop# hwinfo --gfxcard

  Driver: "nouveau"

  Driver Modules: "drm"

  IRQ: 18 (4 events)

root@ubuntu:/home/spinymouse/Desktop# groups spinymouse

spinymouse : spinymouse adm dialout cdrom audio src plugdev lpadmin

admin sambashare

root@ubuntu:/home/spinymouse/Desktop#

cat /etc/security/limits.d/audio.conf

# generated by jackd's postinst.

#

# Do not edit this file by hand, use

#

#    dpkg-reconfigure -p high jackd

#

# instead.

@audio   -  rtprio     99

@audio   -  memlock    unlimited

#@audio   -  nice      -19
The installed rtirq-init is 20090920-0ubuntu1.
root@ubuntu:/home/spinymouse/Desktop# cd /boot

root@ubuntu:/boot# ls

abi-2.6.31-10-rt       config-2.6.32-21-preempt

initrd.img-2.6.32-23-preempt  vmcoreinfo-2.6.31-10-rt

vmlinuz-2.6.32-21-preempt

abi-2.6.31-11-rt       config-2.6.32-23-preempt      memtest86+.bin

vmcoreinfo-2.6.31-11-rt       vmlinuz-2.6.32-23-preempt

abi-2.6.32-21-preempt  grub

System.map-2.6.31-10-rt       vmcoreinfo-2.6.32-21-preempt

abi-2.6.32-23-preempt  initrd.img-2.6.31-10-rt

System.map-2.6.31-11-rt       vmcoreinfo-2.6.32-23-preempt

config-2.6.31-10-rt    initrd.img-2.6.31-11-rt

System.map-2.6.32-21-preempt  vmlinuz-2.6.31-10-rt

config-2.6.31-11-rt    initrd.img-2.6.32-21-preempt

System.map-2.6.32-23-preempt  vmlinuz-2.6.31-11-rt

root@ubuntu:/boot# cat config-2.6.31-11-rt | grep CONFIG_DEVTMPFS

root@ubuntu:/boot# cat config-2.6.32-23-preempt | grep CONFIG_DEVTMPFS

CONFIG_DEVTMPFS=y

CONFIG_DEVTMPFS_MOUNT=y