Tested now a bit further and it seems the problem is isolated to xfwm, I couldn't reproduce it in Unity or TWM. Running xfsettingsd alone with nothing else will produce a short spike of 1 second or so, running xfwm as well will make the problem worse, running the full xfwm4-session will give multiple seconds of unresponsivness.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1200074 Title: High CPU usage and unresponsivness when hotplugging a mouse Status in “xorg-server” package in Ubuntu: New Bug description: 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. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1200074/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
