Bug#747552: mate-power-manager creates popups as persistent, regular windows; leads to huge marco / window switching slowdown

[Stefano Karapetsas]

> Normally, I would file this with lower severity than normal, but
> unfortunately mate-power-manager leaving many windows lying around
> triggers a bug in marco which slows down during window switching
> superlinearly to number of windows (probably roughly O(N^2) or O(N^3)).
>
> In other words, due to this bug (and suboptimal marco implementation)
> after a ~month of usage, about 100 notification windows pile up hidden
> behind other windows and switching windows begins taking near one
> second, with marco exhibiting high CPU load/usage!
>
If you dont want to use a notification daemon, you can disable this kind 
of notifications in GSettings

gsettings set org.mate.power-manager notify-discharging false