For 4K dispaly, I modify gsd-background-manager.c of unity-setting-daemon to dump the resolution of gdk screen and window from g_log, and found that when gdk window got the resolution of 3840x2160, gdk screen still got the resolution of 1920x1080.
For 4K dispaly, I modify gsd-background- manager. c of unity-setting- daemon to dump the resolution of gdk screen and window from g_log, and found that when gdk window got the resolution of 3840x2160, gdk screen still got the resolution of 1920x1080.