[PD] Latency under Linux/Jack (again...)
lsutton at libero.it
Tue Oct 12 21:59:16 CEST 2010
> -RME Multiface I /HDSP expresscard
So this (not the pcmcia) works on linux? That's interesting news.
I also do get some xruns now and then when moving around gui object
(like selecting a whole lot of objects and moving them around) even with
rt kernel, pd run with -rt etc etc...
Otherwise it is usually *quite* stable.
> Of course jack run with -R. I repeat I don't have any problem to run
> application with really good latency: yesterday, I forgot to increase
> buffer as I worked on a 96000Hz Ardour session... I noticed I was
> working at 5ms I/O after one hour recording and playing a lot of tracks,
> and no xrun, no problems...
> I also think it's not a good Idea to run pd as root... and I suppose
> other application won't connect to jack if I run it as root also.
> I noticed I had two times the @audio config (limits.conf, audio.conf).
> You'll say: "better twice than nothing"... But maybe it generates a
> conflict... I try
> Le mardi 12 octobre 2010 à 11:50 -0300, Bernardo Barros a écrit :
>> Don't run programs as root, your system will be as insecure as a windows box...
>> Just allow rt privileges to the audio group, and add yourself to this group.
>> Then start jack with rt privileges. All software linked to Jack will
>> run with -rt.
>> from http://jackaudio.org/faq
>> JACK requires real-time scheduling privileges for reliable,
>> dropout-free operation. The server requests these privileges when
>> running with the -R option.
>> Most recent distributions use PAM to manage the permissions of users
>> on a relatively granular level. If the file /etc/security/limits.conf
>> exists on your system, it is using PAM. In order to configure PAM such
>> that normal users can run jackd with realtime privileges make sure the
>> following lines exist:
>> @audio - rtprio 99
>> @audio - memlock unlimited
>> 2010/10/12 Pedro Lopes<pedro.lopes at ist.utl.pt>:
>>> If you start pd in sudo, you have to connect to jack in sudo mode. Thus
>>> start jack in sudo (or gksudo for qjackctl).
>>> I advise to use an rt kernel too. See documentation of Ubuntu Studio.
>>> On Tue, Oct 12, 2010 at 3:27 PM, Raphael Raccuia
>>> <rafael.raccuia at blindekinder.com> wrote:
>>>> Hi list,
>>>> I tested Pd rt as I need low latency for a performance next week...
>>>> It seems -rt flag doesn't have any effect. I measured Pd latency with
>>>> jdelay, and always get 640 (@48000), so about 13ms (pd only)... lower I
>>>> set buffer in jack (no less than 256), more DIO errors I get... and
>>>> there are a lot! This setting works great with many application
>>>> (Ardour...), with about 10ms (~15 really). So I would have ~25ms, which
>>>> is acceptable, but too many DIO errors!
>>>> -what is -defeatrt setting? (I tried 0 and 1, no change)
>>>> -why is -rt flag without effect?
>>>> -tried nosleep, no change...
>>>> I also tried to start pd in root (sudo)...
>>>> It says:
>>>> priority 8 scheduling enabled.
>>>> priority 6 scheduling enabled.
>>>> (which I normally don't have)
>>>> but unfortunately can't connect to jack (state 17)
>>>> thank's for your help
>>>> Pd-list at iem.at mailing list
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>>> Pedro Lopes (ongoing MSc)
>>> contact: pedro.lopes at ist.utl.pt
>>> website: http://web.ist.utl.pt/Pedro.Lopes
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