29 Oct
2012
29 Oct
'12
5:10 p.m.
On 10/29/2012 03:55 PM, Ivica Ico Bukvic wrote:
All,
I noticed since upgrading to Ubuntu 12.04 that the default Jack server is
jackdmp (v.1.9.8). Please correct me if I am wrong but my understanding this
is the smp-enabled version 2 that is being developed in parallel with 1.x
series of regular jack.
correct. They are also API and ABI compatible.
Either way, one of my concerns is that while in the
old jack when one
accidentally pulled the soundcard jack was trying to talk to (e.g. a USB
soundcard), the jack would gracefully stop.
In my experience it stopped but never gracefully (ie it crashed). but
it's been a while since I used jack1.
The new version (and this could
be Ubuntu quirk) instead of stopping is pegged in some kind of a spinlock
that often times locks up the machine (this may be in part since I am
running a lowlatency kernel with audio group given priority) and at times
keeps it operational while hogging the cpu and making the computer barely
responsive until jackd is killed. Apps connected to jack that I tested so
far are also stuck in a loop waiting for a response from jack (although this
could be the app's shortcoming)--jack never broadcasts a signal that it has
lost the soundcard (AFAICT). FWIW I am running jackdmp through qjackctl...
Any thoughts on this matter would be most appreciated.
I can't reproduce this. jack2 stops the backend when the device is
disconnected. You can switch to a new backend using jack_control
(sending some Dbus messages to jackd) without re-starting jackd. No CPU
hogging here. - I'm running jack2 - aka 1.9.9.4 from git.
robin