Hi, Sean! I hope you don't mind me correcting some inaccuracies in your mail :) On Sun, Apr 13, 2008 at 01:07:39PM -0400, Sean McNamara wrote: > When you start PA with --daemonize=true (the default > in /etc/pulse/daemon.conf), The default is actually "daemonize = no" in daemon.conf. But maybe your distro has decided to modify the default. > If you want > to see what's going on for a single console invocation of PA, you can > try > pulseaudio -vvvv --daemonize=false > It will then output all the debugging info to the console. The first v > is for errors; the second, warnings; the third, notices; the fourth, > debugging. Sometimes two v's isn't enough to get the full picture. Two v's are enough to get the debug output. Without any v's warnings and errors are shown. > > Here are the messages that get logged when I try starting the server: > > > > Apr 13 18:27:52 lily pulseaudio[26288]: main.c: setrlimit(RLIMIT_NICE, (31, 31)) failed: Operation not permitted > > Apr 13 18:27:52 lily pulseaudio[26288]: main.c: setrlimit(RLIMIT_RTPRIO, (9, 9)) failed: Operation not permitted > > These two calls are PA's attempt to get real-time scheduling permission. Those two calls are PA's attempt to set a couple of resource limits, but at that point pulseaudio has changed the user to "pulse", and it doesn't have the permissions to modify the limits. This feels like a bug, and I think the rlimits should not be read from a user-modifiable file. That would make it possible to set the limits at an earlier stage (hmm... I suspect that it wouldn't help with system-wide mode after all, unless the limits can somehow survive the user switch). The error about nice doesn't mean anything, because at this point setting the nice value of the process has already happened. The error about rtprio means that pulseaudio won't be able to use real-time scheduling (that's different thing than high-priority). > There are several reasons why this may not work (no PolicyKit, incorrect > PolicyKit configuration, users not belonging to the right groups, etc.), > but these errors are not fatal. The only surefire way to get realtime > permissions regardless of system configuration is to start PA as root > with --system=false. That might work, but pulseaudio isn't meant to be run as root. When running as a per-user daemon, all it takes to enable real-time scheduling is to put the user to pulse-rt group (and make sure the pulseaudio executable is suid root, I think there was some distro that didn't have that by default). And of course real-time scheduling has to be enabled in daemon.conf. I don't know if PolicyKit will change something about this. Another thing that I don't know is how to enable real-time scheduling in system-wide daemon. Maybe configuring the rtprio resource limit for user "pulse" in /etc/security/limits.conf could work. The rest of the mail was good advice. -- Tanu Kaskinen
