I'd Tap That
So, I just spend the whole night playing around with Systemtap. A neat way to dynamically instrument the kernel.
As far as I know, it uses the kprobe interface to do the hard work. The neat thing about it is, the fact that you use a rather safe language to write the code that’ll get inserted into the kernel. This code then gets translated into C code, which then gets compiled as a kernel module.
When I first heard about systemtap, I decide to ignore it for whatever reason. Now, I’m kind of sorry I did, because it definitely looks like a very useful tool.