[PlanetCCRMA] The JACK Story

Orcan Ogetbil oget.fedora at gmail.com
Sat Nov 21 20:20:09 PST 2009

On Sat, Nov 21, 2009 at 10:55 PM, Fernando Lopez-Lezcano wrote:
> On Sat, 2009-11-21 at 22:02 -0500, Orcan Ogetbil wrote:
>> Do you alternate for specific tasks?
> I have never had to "downgrade" to jack1.
> (I seem to recall somebody having a problem with jack2 and that's why I
> have been keeping a jack1 package available as well - hopefully that
> person will add to the thread)

Hmm. Then we might as well update Fedora's jack to 2. You are the boss
here, you know better. But yes, let's first wait for some response. Do
you know why they keep developing jack1?

>> Would you like to have them parallelly installable? We can achieve
>> parallel installation via "alternatives".
> I'm not completely sure if that is possible. Keep in mind that all jack
> server and client _libraries_ need to be switched in and out (ie: it is
> not just a matter of switching the jackd binaries.

I am confident that we can handle it. Java, as a much bigger suite
with many libraries, does it. We will have to reside the actual
binaries+libraries in certain directories and alternatives will do its
magic with the symlinks.

> The jack2 (and jack1) package in Planet CCRMA also has a different
> default priority that matches the best choice for the rt kernel (plus
> optimized irqs using rtirq). That is not really compatible with the
> current Fedora kernels (default priority is 60, below the irqs for the
> soundcards but above all others). It won't hurt, but I presume it will
> not fly either...

I understand. But in case we update Fedora's jack to 2, you can add a
priorities file to kernel-rt's RPM that will go into

(By the way, the current convention is to use that folder rather than
editing limits.conf.)


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