Bug#853132: pulseaudio-module-jack: modules fail to load due to real-time scheduling

[Felipe Sateler]

Control: tags -1 moreinfo

On 29 January 2017 at 22:25, Vít Novotný <witiko at mail.muni.cz> wrote:
> Package: pulseaudio-module-jack
> Version: 9.0-5
> Severity: grave
> Justification: renders package unusable
>
> Dear Maintainer,
>
> After installing pulseaudio-module-jack, running jackd via
>
>     $ jackd -d alsa
>
> and executing
>
>     $ pactl load-module module-jack-sink
>     $ pactl load-module module-jack-source
>
> the following messages are written out to `/var/log/syslog`:
>
>     Jan 30 01:19:36 inspiron pulseaudio[1198]: [pulseaudio] sink.c: Default and alternate sample rates are the same.
>     Jan 30 01:19:36 inspiron pulseaudio[1198]: [pulseaudio] module-jack-sink.c: JACK error >Cannot use real-time scheduling (RR/5)(1: Operation not permitted)<
>     Jan 30 01:19:36 inspiron pulseaudio[1198]: [pulseaudio] module-jack-sink.c: JACK error >JackClient::AcquireSelfRealTime error<
>     Jan 30 01:19:48 inspiron pulseaudio[1198]: [pulseaudio] source.c: Default and alternate sample rates are the same.
>     Jan 30 01:19:48 inspiron pulseaudio[1198]: [pulseaudio] module-jack-source.c: JACK error >Cannot use real-time scheduling (RR/5)(1: Operation not permitted)<
>     Jan 30 01:19:48 inspiron pulseaudio[1198]: [pulseaudio] module-jack-source.c: JACK error >JackClient::AcquireSelfRealTime error<
>
> Note that the debian installer correctly produced the file
> `/etc/security/limits.d/audio.conf` with the following contents:
>
>     # Provided by the jackd package.
>     #
>     # Changes to this file will be preserved.
>     #
>     # If you want to enable/disable realtime permissions, run
>     #
>     #    dpkg-reconfigure -p high jackd
>
>     @audio   -  rtprio     95
>     @audio   -  memlock    unlimited
>     #@audio   -  nice      -19
>
> and both my user account and pulse are in the unix group `audio`.  Since
> `jackd` (package `jackd2`, 1.9.10+20150825git1ed50c92~dfsg-4) alone has
> no issue setting its real-time priority to 20 and above, this seems to
> be an issue with `libjack`.
>
> If I run
>
>     $ pactl set-default-sink jack_out
>     $ pactl set-default-source jack_in
>
> afterwards, the pulseaudio default sink and source are redirected, but
> no sound results (userland applications such as mpv claim that the
> ,,stream is suspended``). If I run `jackd` outside real-time mode:
>
>     $ jackd --no-realtime -d alsa
>
> then only the following logs are produced:
>
>     Jan 30 01:19:36 inspiron pulseaudio[1198]: [pulseaudio] sink.c: Default and alternate sample rates are the same.
>     Jan 30 01:19:48 inspiron pulseaudio[1198]: [pulseaudio] source.c: Default and alternate sample rates are the same.
>
> but after running
>
>     $ pactl set-default-sink jack_out
>     $ pactl set-default-source jack_in
>
> there is no sound nevertheless.
>
> Note that both pulseaudio and jack work flawlessly separately. The
> issue is in making pulseaudio work as a jack client.

Could you attach a verbose log when reproducing the problem?

https://wiki.ubuntu.com/PulseAudio/Log


-- 

Saludos,
Felipe Sateler