Don't know if you already have read about this but here it goes.

"Fixed: The Linux Desktop Responsiveness Problem?"

Also releated it's this

Sometimes my N900 get's stuck when making a photo or so, and I think this would make my N900 feel snappier in some cases. Maybe it can be ported to the N900. Also, it does seem the right way should be compile this newer version of the Linux kernel for the N900 rather than backporting the patches. Does anyone have any idea??