Public bug reported: In both XUbuntu 13.04 and 13.10 Xorg will spike to 100% CPU usage for around 15 seconds whenever I hotplug a USB mouse. In this time not only is the CPU used fully, Xorg itself also becomes non-responsive, the mouse pointer itself, even from the newly plugged in mouse, will move just fine, but focus changes and button presses won't be registered until 15 seconds later. When I look with xev at the events at that time I will see around 4000 lines of this:
MappingNotify event, serial 37, synthetic NO, window 0x0, request MappingKeyboard, first_keycode 10, count 1 MappingNotify event, serial 37, synthetic NO, window 0x0, request MappingKeyboard, first_keycode 10, count 1 MappingNotify event, serial 37, synthetic NO, window 0x0, request MappingKeyboard, first_keycode 10, count 1 MappingNotify event, serial 750, synthetic NO, window 0x0, request MappingKeyboard, first_keycode 218, count 1 [...] MappingNotify event, serial 750, synthetic NO, window 0x0, request MappingKeyboard, first_keycode 218, count 1 MappingNotify event, serial 750, synthetic NO, window 0x0, request MappingKeyboard, first_keycode 218, count 1 MappingNotify event, serial 750, synthetic NO, window 0x0, request MappingModifier, first_keycode 0, count 0 MappingNotify event, serial 750, synthetic NO, window 0x0, request MappingModifier, first_keycode 0, count 0 Some applications, most noticably xfce4-volumed, will themselves spike in CPU usage as a return to Xorg doing it and prolong the problem up to multiple minutes. But as the problem happens even without them running they don't seem to be the cause of it. ** Affects: xorg-server (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1200074 Title: High CPU usage and unresponsivness when hotplugging a mouse To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1200074/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs