figuring out which ioctl's a system needs?

I'm trying to figure out what is the subset of ioctl's a system needs to run. I figure the best way is sticking a printk in sys_ioctl, and having it printk the number, so that syslog can pick it up, and then go through the list. This way I can use the system normally for a week to collect the information I need.

Is there an easier way, or is there a way that I can make my life easier (i.e. going from printk'd number to header file include).

thanks,

shaya potter