Bug#1022119: Wakes up every 1.5s even with no work to do

[Samuel Thibault]

Josh Triplett, le jeu. 20 oct. 2022 16:59:04 +0100, a ecrit:
> On Thu, Oct 20, 2022 at 03:24:48PM +0200, Samuel Thibault wrote:
> > Control: reassign -1 pulseaudio
> > 
> > Samuel Thibault, le jeu. 20 oct. 2022 15:02:09 +0200, a ecrit:
> > > Josh Triplett, le jeu. 20 oct. 2022 13:45:45 +0100, a ecrit:
> > > > sd_dummy seems to be waking up every 1.5s even when it has no work to
> > > > do.
> > > 
> > > I don't see that happening on my system. Could you run strace on it so
> > > we get to know what happens in your case? E.g.
> > > 
> > > strace -p $(pgrep sd_dummy)
> > 
> > Ah, -f is needed to see the thread started by pulseaudio.
> > 
> > (gdb) bt
> > #0  0x00007fb4fdefe32f in __GI___poll (fds=fds at entry=0x7fb4f40071a0, nfds=nfds at entry=2, timeout=timeout at entry=1500) at ../sysdeps/unix/sysv/linux/poll.c:29
> > #1  0x00007fb4fe0652e1 in poll (__timeout=1500, __nfds=2, __fds=0x7fb4f40071a0) at /usr/include/x86_64-linux-gnu/bits/poll2.h:39
> > #2  poll_func (ufds=0x7fb4f40071a0, nfds=2, timeout=1500, userdata=0x56184db546b0) at ../src/pulse/thread-mainloop.c:70
> > #3  0x00007fb4fe056fa4 in pa_mainloop_poll (m=m at entry=0x56184db545b0) at ../src/pulse/mainloop.c:863
> > #4  0x00007fb4fe057606 in pa_mainloop_iterate (m=m at entry=0x56184db545b0, block=block at entry=1, retval=retval at entry=0x0) at ../src/pulse/mainloop.c:945
> > #5  0x00007fb4fe0576b0 in pa_mainloop_run (m=0x56184db545b0, retval=retval at entry=0x0) at ../src/pulse/mainloop.c:963
> > #6  0x00007fb4fe0653b9 in thread (userdata=0x56184db54560) at ../src/pulse/thread-mainloop.c:101
> > #7  0x00007fb4fd5d433f in internal_thread_func (userdata=0x56184db5ad20) at ../src/pulsecore/thread-posix.c:81
> > #8  0x00007fb4fde8784a in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
> > #9  0x00007fb4fdf0b2cc in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
> > 
> > so that's coming from pulseaudio. The 1500 delay is most probably
> > coming from
> > 
> > ./src/pulse/stream.c:#define AUTO_TIMING_INTERVAL_END_USEC (1500*PA_USEC_PER_MSEC)
> > 
> > I don't know why pulseaudio would be waking up every 1.5s even if the
> > speech module doesn't submit any audio.
> 
> In case it matters, I'm using pipewire, not pulseaudio.

I understood that, but on the client side it's the pulseaudio library
which is used.

Samuel