Comment 25 for bug 558657

I see similar problems on my work machine running an NV50-class (160M?) gpu with nouveau. not sure if this will help, but..

I think there are two bugs here. There is one bug in the nouveau driver and a hardware cursor where the hw cursor engine will eventually stop displaying the cursor, especially with two monitors (as each time you switch monitors it causes this cursor reset, or something). this is indicated by the "no space for cursor" type messages in the kernel log which eventually culminate in a message (from faded memoy) "[drm] EvtChg <blah>...", and after that, the cursor won't show on one of the monitors again until a reboot. .I -occasionally- saw this in Lucid with two monitors (maybe once a month), but with maverick it happened every few hours at least. I switched to a software cursor and stopped using my second monitor.

So, upshot is, you may want to try disabling the hardware cursor and see if you have better luck.

The second is that now, using the software cursor, depending on where on the screen I am, just hovering the mouse over a spot in a gtk app causes cpu usage to spike in Xorg, like it's constantly re-drawing the widget that's under the mouse. Hover the mouse over Xterm window and everything's fine. Open a nautilus window and hover over the sidebar, Xorg jumps to 100% and stays there until you move the mouse off, but if you hover over the file icons or the menu, you're fine. Firefox and Thunderbird also have "sensative areas" of the app which cause cpu usage spikes.

So, either we need to fix the hardware cursor in nouveau, or fix the software cursor cpu usage issues.

In general, nouveau was much more stable under Lucid and under Maverick, at least on my box. I have no such issues at home running the intel or OSS radeon drivers.