Re: [Jack-Devel] jack 1.9.8 + many many connections = problems?

On 12/28/2011 03:26 AM, Fons Adriaensen wrote:
> On Tue, Dec 27, 2011 at 06:03:23PM -0800, Fernando Lopez-Lezcano wrote:
>
>> It would seem that something bad is happening when all ports are being
>> connected and the end result is that inside jack some of the soundcard
>> ports seem to go nowhere.
>>
>> The aj-snapshot process that connects everything takes a bit to run and
>> as it progresses jack reports more and more xruns until it finishes. It
>> would seem that something is running inside jack when ports are
>> connected that is proportional to the number of existing connections
>> (the graph reordering?, that would make sense - but it should not
>> generate xruns, right?).
>>
>> It also appears to be that if I minimize the number of ports I'm
>> connecting the problem goes away (but then of course the system is not
>> completely functional :-).
>>
>> Clues?
>> Ways to debug?
>
> The complexity of the graph doesn't directly depend on the number
> of ports - all that matters is if app A is driving app B or not.
> The algorithms used to manage the graph should take advantage
> of that, but I don't know if they do. Anyway I'd suspect the
> problem to be with individual port/conncection management.
>
> Suggestions:
>
> - If you have any apps using port/connection callbacks, remove
>    these.

Hmmm, I'll check, I don't think so (all apps are stock except for the sc 
program - I'm not setting any callbacks myself).

I did try to use "-v" in jackd to see more details but the amount of 
stuff being printed out slowed down things so much it did not work (most 
was about recalculating port latencies - maybe after each connection?).

> - Patch aj-snapshot so it delivers a fixed number of requests
>    per unit time instead of running as-fast-as-possible.

I did add a delay after each connection yesterday and it did not seem to 
make a difference.

One more test that occurred to me overnight is to send noise over the 
troublesome channels starting right before the aj-snapshot run starts, 
to really really make sure that the connection process is what is 
causing the problem.

Thanks for the suggestions!
-- Fernando

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