Bug 1390043

Also "pactl list" says:

Module #7
        Name: module-jackdbus-detect
        Argument: channels=2
        Usage counter: n/a
        Properties:
                module.author = "David Henningsson"
                module.description = "Adds JACK sink/source ports when JACK is started"
                module.version = "8.0"

While testing I noticed errors in the log like "module-jack-sink.c: JACK error >Cannot use real-time scheduling (RR/15)(1: Operation not permitted)<".  I'd already raised the relevant ulimit.  It appears pulseaudio was setting the RESET_ON_FORK code and then jack code was attempting to clear it, so sched_setscheduler() calls without RESET_ON_FORK were failing with EPERM.  So the errors went away after removing the code that set RESET_ON_FORK (see below).  That doesn't actually fix the problem, so was just a distraction.  (But seems like a bug itself, whether this is the right fix or not).

diff --git a/src/pulsecore/core-util.c b/src/pulsecore/core-util.c
index 873f86a0e5b2..15d55b5fec26 100644
--- a/src/pulsecore/core-util.c
+++ b/src/pulsecore/core-util.c
@@ -713,12 +713,6 @@ static int set_scheduler(int rtprio) {
     pa_zero(sp);
     sp.sched_priority = rtprio;
 
-#ifdef SCHED_RESET_ON_FORK
-    if (pthread_setschedparam(pthread_self(), SCHED_RR|SCHED_RESET_ON_FORK, &sp) == 0) {
-        pa_log_debug("SCHED_RR|SCHED_RESET_ON_FORK worked.");
-        return 0;
-    }
-#endif
 
     if (pthread_setschedparam(pthread_self(), SCHED_RR, &sp) == 0) {
         pa_log_debug("SCHED_RR worked.");

Ugh, this is just user error.  I missed that there's some manual configuration required, either to choose the new Jack sink/source audio devices in the gnome sound settings dialog, or make the right connections in jack, I'm not quite clear which.  It's annoying that this isn't more automatic, but this was basically my fault.

The issue in comment 2 still looks like a bug, though.

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