Real Time Kernel
Steven Rostedt has worked for Red Hat over the last 8 years. His primary duty is working on the Real Time Kernel. But since that requires the full analysis of the kernel internals, he developed ftrace (the official Linux tracer) to facilitate the examination of what is happening. Ftrace is now used by most kernel developers outside the Real Time work. Steven is now the maintainer of ftrace and that has consumed most of his time away from working on the RT kernel, although he still maintains the RT kernel stable releases. Ftrace has proven to be much more powerful than simple tracing, as its infrastructure is being used by other tools and subsystems such as perf and kprobes. The facility to hook into a function at its start has allowed for new functionality; live kernel patching.