[Ardour-Users] ardour 3.0 alpha season drawing to an end

[Robin Gareus]

On 07/16/2011 06:38 PM, Wayne wrote:
> Il giorno sab, 16/07/2011 alle 18.29 +0200, Robin Gareus ha scritto: 
[.snip.]

>>
>> feeding back here from a discussion on jack-devel email-list:
>>
>> This is a JACK2 specific issue and only occurs when jack2 is run in
>> asynchronous mode.
>>
>> Basically the "JackActivationCount" message is generated when an x-run
>> occurs. More specifically: This message happens when a client could not
>> "consume" it's activation in time on a given cycle, and it triggered again.
> 
> 
>     thanks for the update.  is this problem with "consuming its
> activation" in time due to a problem with the app (Ardour 3 in this
> case)?  or is this something that can be ignored safely? 

It's [just a special incarnation of] an x-run.

> ... as if
> anything can safely ignored ;)  basically, i have no idea what is meant
> by a "client could not consume its activation in time", and what this
> means about the client?

IOW: the system was too busy to run a jack-client (i.e ardour) in time.


>> Since jackdmp svn r4491 this message is no longer assumed to be an
>> "error" but simply a "warning" and thus won't show up in ardour's log
>> any more.
> 
> 
>     glad to hear it.  i will update and give it a go.  however, as
> above, is it indicating some other problem?  i do notice that when i get
> this message, i always get a few XRUNs.  could just be due to the Log
> window popping up?

They're related. Usually the x-run is first (and only a transient
condition) but popping up the log window, adding the message, scrolling
it to the bottom, etc increases the system load.  More x-runs, more of
the messages appear,.. even more system-load, more x-runs.. (until there
is one "JackActivationCount" message for each cycle) and
the jack-client (here: ardour3) is becoming unresponsive.


>> Alternatively, it won't ever show up in when running jackd2 in
>> synchroneous mode:
>>   launch jackd: jackd -S ...
>>   or with jackdbus : `jack_control eps sync true`
> 
>     does this not disable one of the "features" of JACK2, i.e.
> asynchronous data flow (assuming one has some audio data moving in
> parallel)?

It does. However note that this "feature" also adds 1 cycle of latency.
YMMV.

ciao,
robin