e0fd7a6d05
When profiling gnome-shell it was found that one of the main triggers of `clutter_actor_queue_relayout` during animations was `clutter_actor_set_margin_internal` continuously setting the same zero margins. That's obviously pointless and also expensive. So just avoid redundant margin changes. This helps to further improve performance in: https://gitlab.gnome.org/GNOME/mutter/issues/233, https://gitlab.gnome.org/GNOME/gnome-shell/issues/349 This change previously landed as 59acb3895 and then got reverted because it was found to make gnome-shell#517 worse. However that bug now has a proper fix and this branch isn't really directly related so is being reproposed...
Mutter
Mutter is a Wayland display server and X11 window manager and compositor library.
When used as a Wayland display server, it runs on top of KMS and libinput. It implements the compositor side of the Wayland core protocol as well as various protocol extensions. It also has functionality related to running X11 applications using Xwayland.
When used on top of Xorg it acts as a X11 window manager and compositing manager.
It contains functionality related to, among other things, window management, window compositing, focus tracking, workspace management, keybindings and monitor configuration.
Internally it uses a fork of Cogl, a hardware acceleration abstraction library used to simplify usage of OpenGL pipelines, as well as a fork af Clutter, a scene graph and user interface toolkit.
Mutter is used by, for example, GNOME Shell, the GNOME core user interface, and by Gala, elementary OS's window manager. It can also be run standalone, using the command "mutter", but just running plain mutter is only intended for debugging purposes.
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.