I use pulse with jack via jackdbus. I've been trying to narrow down the cause of a series of errors I've been seeing in my pulseaudio logs for some time: Jun 21 08:43:46 localhost pulseaudio[1988]: W: [pulseaudio] module-jack-sink.c: JACK error >Cannot use real-time scheduling (RR/15)(1: Operation not permitted)< Jun 21 08:43:46 localhost pulseaudio[1988]: W: [pulseaudio] module-jack-source.c: JACK error >Cannot use real-time scheduling (RR/15)(1: Operation not permitted)< Jun 21 08:44:40 localhost pulseaudio[2596]: W: [pulseaudio] module-jack-sink.c: JACK error >Cannot use real-time scheduling (RR/15)(1: Operation not permitted)< Jun 21 08:44:40 localhost pulseaudio[2596]: W: [pulseaudio] module-jack-source.c: JACK error >Cannot use real-time scheduling (RR/15)(1: Operation not permitted)< Running pulse in a higher verbosity I get: I: [pulseaudio] module-jack-sink.c: Successfully connected as 'PulseAudio JACK Sink' I: [pulseaudio] module-device-restore.c: Restoring volume for sink jack_out: front-left: 45922 / 70%, front-right: 45922 / 70% I: [pulseaudio] module-device-restore.c: Restoring mute state for sink jack_out: unmuted W: [pulseaudio] sink.c: Default and alternate sample rates are the same. I: [pulseaudio] sink.c: Created sink 3 "jack_out" with sample spec float32le 2ch 48000Hz and channel map front-left,front-right I: [pulseaudio] sink.c: device.api = "jack" I: [pulseaudio] sink.c: device.description = "Jack sink (PulseAudio JACK Sink)" I: [pulseaudio] sink.c: jack.client_name = "PulseAudio JACK Sink" I: [pulseaudio] sink.c: device.icon_name = "audio-card" I: [pulseaudio] module-device-restore.c: Restoring volume for source jack_out.monitor: front-left: 65536 / 100%, front-right: 65536 / 100% I: [pulseaudio] source.c: Created source 5 "jack_out.monitor" with sample spec float32le 2ch 48000Hz and channel map front-left,front-right I: [pulseaudio] source.c: device.description = "Monitor of Jack sink (PulseAudio JACK Sink)" I: [pulseaudio] source.c: device.class = "monitor" I: [pulseaudio] source.c: device.icon_name = "audio-input-microphone" I: [pulseaudio] module-jack-sink.c: JACK thread starting up. I: [pulseaudio] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 9. I: [jack-sink] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 5. I: [pulseaudio] module-jack-sink.c: JACK buffer size changed. I: [pulseaudio] module-jack-sink.c: JACK thread starting up. I: [pulseaudio] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 9. W: [pulseaudio] module-jack-sink.c: JACK error >Cannot use real-time scheduling (RR/15)(1: Operation not permitted)< W: [pulseaudio] module-jack-sink.c: JACK error >JackClient::AcquireSelfRealTime error< I: [pulseaudio] module-jack-sink.c: JACK thread starting up. I: [pulseaudio] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 9. I: [pulseaudio] module.c: Loaded "module-jack-sink" (index: #24; argument: "connect=no channels=2"). I: [pulseaudio] module-jackdbus-detect.c: Successfully started module-jack-sink. I: [pulseaudio] module-jack-source.c: Successfully connected as 'PulseAudio JACK Source' I: [pulseaudio] module-device-restore.c: Restoring volume for source jack_in: front-left: 65536 / 100%, front-right: 65536 / 100% I: [pulseaudio] module-device-restore.c: Restoring mute state for source jack_in: unmuted W: [pulseaudio] source.c: Default and alternate sample rates are the same. I: [pulseaudio] source.c: Created source 6 "jack_in" with sample spec float32le 2ch 48000Hz and channel map front-left,front-right I: [pulseaudio] source.c: device.api = "jack" I: [pulseaudio] source.c: device.description = "Jack source (PulseAudio JACK Source)" I: [pulseaudio] source.c: jack.client_name = "PulseAudio JACK Source" I: [pulseaudio] source.c: device.icon_name = "audio-input-microphone" I: [pulseaudio] module-jack-source.c: JACK thread starting up. I: [pulseaudio] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 9. I: [jack-source] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 5. I: [pulseaudio] module-jack-source.c: JACK thread starting up. I: [pulseaudio] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 9. W: [pulseaudio] module-jack-source.c: JACK error >Cannot use real-time scheduling (RR/15)(1: Operation not permitted)< W: [pulseaudio] module-jack-source.c: JACK error >JackClient::AcquireSelfRealTime error< I: [pulseaudio] module-jack-source.c: JACK thread starting up. I: [pulseaudio] core-util.c: Successfully enabled SCHED_RR scheduling for thread, with priority 9. I: [pulseaudio] module.c: Loaded "module-jack-source" (index: #25; argument: "connect=no channels=2"). I: [pulseaudio] module-jackdbus-detect.c: Successfully started module-jack-source. I've played around with ulimit and cgroups but by distro defaults(Fedora 28) seem to be fine as I can run processes via prlimit [user at localhost ~]$ sudo cat /etc/security/limits.d/95-jack.conf # Default limits for users of jack-audio-connection-kit @jackuser - rtprio 70 @jackuser - memlock 4194304 @pulse-rt - rtprio 20 @pulse-rt - nice -20 [user at localhost ~]$ prlimit --rtprio=70 --rttime=unlimited echo [user at localhost ~]$ echo $? 0 [user at localhost ~]$ prlimit --rtprio=71 --rttime=unlimited echo prlimit: failed to set the RTPRIO resource limit: Operation not permitted [user at localhost ~]$ echo $? 1 So the settings appear to be correct yet the pulse jack module still complains about not being able to properly set the RT priority? Any insight would be appreciated.
