During a recent effort to reduce unnecessary wakeups of userspace applications (in preparation for tickless kernels), it was brought to my attention that the GNOME workspace switcher applet wakes up for every key press in any window on the desktop.
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=204968 The same happens with metacity; we're taking ~6 context switches per key press, which is "not nice" for battery life on laptops. It happens because the workspace switcher listens for property changes on all toplevel windows (to catch icon changes, etc). And GTK+ follows the EWMH and updates the _NET_WM_USER_TIME property on every user input. A simple solution for this problem is to put the _NET_WM_USER_TIME property on a separate window. Then applications listening for changes of the toplevel window properties are not affected by its frequent changes. I'd like to propose the following addition to the EWMH: _NET_WM_USER_TIME_WINDOW WINDOW/32 This property contains the XID of a window on which the client sets the _NET_WM_USER_TIME property. Clients should check whether the window manager supports _NET_WM_USER_TIME_WINDOW and fall back to setting the _NET_WM_USER_TIME property on the toplevel window if it doesn't. Rationale: Storing the frequently changing _NET_WM_USER_TIME property on the toplevel window itself causes every application that is interested in any of the properties of that window to be woken up on every keypress, which is particularly bad for laptops running on battery power. I have a patch which implements this in GTK+, and Elijah indicated that he is willing to change Metacity to support _NET_WM_USER_TIME_WINDOW. Matthias PS I should not forget to mention that Owen already pointed out this problem and the proposed solution when _NET_WM_USER_TIME was discussed in 2003: http://mail.gnome.org/archives/wm-spec-list/2003-May/msg00047.html _______________________________________________ wm-spec-list mailing list wm-spec-list@gnome.org http://mail.gnome.org/mailman/listinfo/wm-spec-list
