Hi,
I am trying to figure out why PulseAudio daemon drops a few samples
from time to time.
I got a few null sinks combined with each other by loopbacks. Then my
applications gather sound from their .monitors. Sounds simple.
I quickly came to idea that running PulseAudio in RT mode could help.
I encountered a lot of problems, because:
- my PA daemons are started at the boot time (but as normal users!)
and start-stop-daemon know nothing about /etc/security/limits.conf, so
I got troubles with setting limits for them without setting RT limits
for the whole system,
- PA daemon tries to communicate to rtkit and rtkit tries to
communicate to PolicyKit which becomes the next dependency for me
etc...
During the process I started to investigate pulseaudio & rtkit source
code and I found something strange.
e.g. combine module tries to acquire realtime priority during thread
initialization:
static void thread_func(void *userdata) {
struct userdata *u = userdata;
pa_assert(u);
pa_log_debug("Thread starting up");
if (u->core->realtime_scheduling)
pa_make_realtime(u->core->realtime_priority+1);
pa_thread_mq_install(&u->thread_mq);
while e.g. NULL sink doesn't:
static void thread_func(void *userdata) {
struct userdata *u = userdata;
pa_assert(u);
pa_log_debug("Thread starting up");
pa_thread_mq_install(&u->thread_mq);
What is the reason for that?
For me, it means that even if I solve all problems mentioned above, my
NULL sinks still wouldn't be using realtime scheduler policy?
Shouldn't it be fixed?
m.
