Audacious creates 133 wakeups while being idle

[Rafał Krypa]

On Tue, 2007-10-23 at 00:31 +0200, Peter Hüwe wrote:
On Tuesday 23 October 2007 00:13:22 Alan Jenkins wrote:
> > Peter Hüwe wrote:
> > > Hi,
> > >
> > > I noticed that audacious (music player) creates 133 wakeups while
being
> > > in idle mode (i.e. playback stopped)
> > > ->This is quite a huge amount
> > >
> > > Any suggestions how to reduce that amount?
> > > I tried disabling the scrolling song name feature, but that
reduced the
> > > wakeups only by three.
> >
> > If theres an option to increase buffer sizes that might help.
> >
> > I think just keeping an audio device open causes wake-ups on some
> > drivers, even if you're not writing to it.  But it's also possible
your
> > player is writing (silence) to the device.
> >
> > What are the wakeups like when playing?  Much more?  Less?  The
same?
> >
> > It seems to be a common feature of music players, though 133 is
> > excessive.  Amarok does 50/s all the time, idle or playing.  My
guess is
> > these wakeups are probably something most music players do at a low
> > level, and that it's probably more natural to keep the wakeups going
on
> > idle (i.e. it made the code look better and there didn't seem to be
any
> > reason not to do it at the time).  IOW I'd look at the audio output
> > path, not the GUI.
> 
> 
> When Playing the value jumps up to 200 on schedule_timeout and a new
item 
> shows up with 70 wake ups (do_nanosleep)  [+ 50 from the soundcard
driver]
> 
> stracing it shows this:
> http://nopaste.biz/20545
> 
> ls -l /proc/`pgrep audacious`/fd|awk '{print $1 " " $9 " " $10 " "
$11}' 
> 
> lrwx------ 0 -> /dev/pts/2
> lrwx------ 1 -> /dev/pts/2
> lrwx------ 2 -> /dev/pts/2
> lrwx------ 3 -> socket:[73223]
> lr-x------ 4 -> pipe:[73225]
> l-wx------ 5 -> pipe:[13222]
> l-wx------ 6 -> pipe:[73225]
> lr-x------ 7 -> pipe:[13239]
> l-wx------ 8 -> /home/peter/.config/audacious/log
> lrwx------ 9 -> socket:[73231]
> 
> grepping the numbers out of netstat shows en empty result
> 
> 
> 
> Starting audacious headless (i.e. without a GUI) it still creates 100
wakeups
> 
This is unfortunately caused by a design of audacious.
After quick look at the source code I found:

Timeout for GUI:
src/audacious/ui_main.c:2957:
void
> mainwin_attach_idle_func(void)
> {
>     mainwin_timeout_id = g_timeout_add(MAINWIN_UPDATE_INTERVAL,
>                                        mainwin_idle_func, NULL);
> }
> 
MAINWIN_UPDATE_INTERVAL is defined in src/audacious/ui_main.h:

> #define MAINWIN_UPDATE_INTERVAL  10

Timeout for headless:
src/audacious/main.c:1236:
// if we are running headless
>     else
>     {
>         GMainLoop *loop;
> 
>         mainwin_set_info_text();
>         playlist_start_get_info_thread();
> 
>         starting_up = FALSE;
> 
>         loop = g_main_loop_new(NULL, TRUE);
>         g_timeout_add(10, aud_headless_iteration, NULL);
>         g_main_loop_run(loop);
> 
>         return EXIT_SUCCESS;
>     } 
> 
So no matter if you are running with gui or headless, application will
start a 10ms timer for some "main loop" operations.
Getting rid of these wake ups would require moderate changes in the
source, so probably you should notify the author about this issue.