Re: Fedora 16, GTX 550Ti, random X hangs, "Attempted to yield the CPU..."
Unfortunately, there are clearly several issues. "Attempted to yield the CPU..." is just one of them. They happen at different times and varying frequency depending on which NVIDIA driver I am running. I am not running 64 bit for instance and get different backtraces than you.
Sometimes X crashes but I can still ssh into the host , kill X , rmmod nvidia and modprobe nvidia and it will generate a kernel fault and X won't start. This means the card has been pushed into an unusable state and only a reboot resets it.