On Xubuntu 12.04 I found the same /etc/security/limits.d/audio.conf file with rtprio 95 specified for the audio group. So this setting must be around for quite a while, and not limited to Debian / Raspbian. I can't find any documentation or even mailing list discussion explaining the rationale.
Miller has today responded to this fait accompli with the release of pd 0.46-3 which respects that level, so it can't be bothered by jackd's default setting. Thanks Miller! This irons out a lot of the confusion.
By the way I found that when I created /etc/security/limits.d/puredata.conf it has precedence over /etc/security/limits.d/audio.conf, probably because of it's alpha-numerical rank. Would this for pd users be the most transparent option to set real time priority? Or am I overlooking some drawback?
Katja
On Thu, Dec 11, 2014 at 1:32 PM, Kaj Ailomaa zequence@mousike.me wrote:
On Wed, Dec 10, 2014, at 04:23 PM, katja wrote:
On Wed, Dec 10, 2014 at 11:31 AM, Kaj Ailomaa zequence@mousike.me wrote:
On Wed, Dec 10, 2014, at 02:45 AM, katja wrote:
/etc/security/limits.d/audio.conf, with the following content:
@audio - rtprio 95 @audio - memlock unlimited #@audio - nice -19
Doesn't this file come with jackd? Haven't checked on Raspbian, but this is the case on Debian. This works well on Debian, since user is member of audio group by default.
You're right Kaj, the file itself says it: 'provided by the jackd package'. So it's not a Raspbian default. How could I miss that while checking and tweaking the file a dozen times.
I wonder why the file sets real time priority 95, while official jackaudio documentation (http://jackaudio.org/faq/linux_rt_config.html) recommends level 99. If level 95 is Debian tradition, it would be best for pd to comply with that level.
Katja
I think there are some different opinions on what is safe, but I wouldn't be able to explain the difference. That is just the way jackd has been packaged for a while I guess :).