High CPU usage in 1.18 (but not master) when pausing playback in gnome-music
I noticed that there is constant high CPU usage in gnome-music whenever playback is paused. I tried to analyze this with sysprof and basically the entire time is spent in futex syscalls from gst_system_clock_async_thread. This issue can not be reproduced using gst-play-1.0 --use-playbin3, so it probably depends on something that gnome-music is doing.
This issue seems to only affect the 1.18 branch, and can not be reproduced with the current master branch of gstreamer (+plugins-base +plugins-good). I can't find any obvious change in master that claims to fix such an issue though.
I tried to bisect the 1.18 branch and the issue started happening with b39a0606.
The relevant gnome-music code can be found here: https://gitlab.gnome.org/GNOME/gnome-music/-/blob/master/gnomemusic/gstplayer.py