Bug#527642: jackd: jack daemon quits at boot up

[Philip Ashmore]

On Sat, 9 May 2009 11:08:40 +0200, Adrian Knoth wrote:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=527642#10

> Is jackd running afterwards?
No. The "removing stale pid" says it all.
Also, I would have expected a different message from /sbin/start-stop-daemon indicating that the requested daemon is already running.

> Can you try removing -R and -P from the jackd command line?

I added the following to /etc/security/limits.conf as suggested by
realtime settings for audio programs in /etc/security/limits.conf
    http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=507248&archived=False&mbox=no

@audio - rtprio 99
@audio - nice -15
@audio - memlock 250000

I removed the -R and -P 10 and it worked!
I added the -R back and it still works!

Even /sbin/start-stop-daemon knows the score:
    # /etc/init.d/jackd start
    jackd already started; not starting. failed!
To clarify the steps I'm taking it's necessary to tag them with [] below.

[-R works step]
Unfortunately I'm getting overrun errors when I move a window in KDE 3.5.
This is on a Dual core 1.867GHz Intel processor doing not much of anything.
I'll see if rebooting solves this.

[rebooted]
jackd isn't running.
I can do
    /etc/init.d/jackd start
and it complains about the stale pid.
Running it again lets me know that jackd is now running successfully - "jackd already started...".
I'll try removing the -R flag and rebooting...

[rebooted without -R twice]
pgrep -l jackd each time showed that jackd was running at startup two out of two times.

I even tried my original config and it works now, but not at reboot. So this problem is intermittent.
 
ksysguard shows me that jackd is running with a default nice of 0, no matter what priority I specify in /etc/default/jackd.

Why doesn't jackd log error messages?

> Starting jackd as user 'contact' works?
Yes.

Extra info:
I configured kcontrol to use jackd.
In "kcontrol/Sound & Multimedia/Sound System/Hardware/Select your MIDI device" after some reboots "Client-128 qjackctl - ALSA device" option is available, sometimes not.
I configured Amarok's Xine engine to use the jack output plugin.
When it works I get regular dropouts, so I just changed -p to 2048 and I'm getting zero dropouts!?!
I thought -p was the packet size option, but "man jackd" tells me it configures the maximum number of ports!?!
This indicates that this may be a dangling pointer problem.
Qjackctl doesn't save it's settings in ~/.jackdrc like I tell it to and I don't know where it stores it's configurations, but at least it's telling me that I'm now getting zero dropouts, something I can confirm by listening to internet radio with Amarok.

So, long story short (too late) removing -R and -P seems to fix this, but
1. Dropouts seem to depend on the -p (max ports) setting, something it definitely should not do.
2. No system logging in jackd isn't helping.
3. Qjackctl can't seem to determine what the settings of an already started jackd daemon are. I noticed that when I quit qjackctl it caused a dropout once.

Philip