[LAU] Aeolus, synthesized pipe organ

[Fons Adriaensen]

On Sun, Sep 21, 2008 at 12:13:34AM -1000, david wrote:

> Thanks, Fons. It reported these warnings, then went on to start JACK:
> Warning: memory lock failed.
> Warning: can't run midi thread in RT mode.
> Warning: can't run model thread in RT mode.

You can probably have an almost xrun-free system.
You don't need an RT patched kernel for this.

Look at the file /etc/security/limits.conf, and
verify if you have some lines there similar to

@audio          -       rtprio          99
@audio          -       nice            -10
@audio          -       memlock         400000

Instead of @audio there could also be '*'.

If you don't have these, add them (you must be
root to do this). The nmber after 'memlock' 
should be something like 80% of your RAM size.

Verify if you have an 'audio' group. If not, create
it. Make sure your are a member of this group.

In Qjackctl's setup, enable realtime and set 
priority to e.g. 60. Also enable 'memory unlock'.
Make sure you use a raw ALSA device (normally hw:0).
To be on the safe side, set frames/period to 256
and periods/buffer to 3. Try later if things work
with 2 as well.

You should now be able to run jackd in realtime
mode. The three warnings from Aeolus should be
gone as well, and with a bit of luck also most
of the xruns.

> Hmmm, the Jack I have here doesn't show any MIDI clients when I check 
> the MIDI tab. At least, it doesn't show my keyboard. That should be 
> listed as a client, yes?

You have to enable this, it's in the lower left corner
of Qjackctl's setup window. Don't know if Rosegarden
will like this.

Ciao,

-- 
FA

Laboratorio di Acustica ed Elettroacustica
Parma, Italia

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