Here are the first few lines of output from xrestop. I've never used it before so I don't know if "<unknown>"s are normal, but I figured there's a decent chance they're related so they might be relevant to this ticket:
res-base Wins GCs Fnts Pxms Misc Pxm mem Other Total PID Identifier 1a00000 7 3 1 20 61 18257K 2K 18259K 2210 Desktop 0e00000 305 2 1 47 4419 13944K 111K 14055K ? Compiz 0600000 0 0 0 1 0 9000K 0B 9000K ? <unknown> 0c00000 6 3 0 18 559 6212K 13K 6225K 2173 gnome-settings 0000000 2 0 2 0 155 6075K 5K 6080K ? <unknown> 1800000 0 0 0 1 0 6075K 0B 6075K ? <unknown> 3e00000 44 92 1 184 436 4606K 14K 4620K 3621 Changeset 3162 3000000 3 2 0 1 15 4500K 480B 4500K 2539 gnome-screensa 4000000 21 89 1 143 211 4181K 8K 4190K 8545 New Tab - Chro 2e00000 6 86 1 33 58 3347K 4K 3352K 3129 Virtual Machin 2800000 1706 68 1 119 431 2605K 52K 2658K 2329 gtk-window-dec 2400000 34 3 0 14 103 88K 3K 91K 2268 unity-panel-se -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-intel in Ubuntu. https://bugs.launchpad.net/bugs/935630 Title: White rectangular To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/935630/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp