What:		/sys/kernel/debug/tracing
Date:		May 2008
KernelVersion:	2.6.27
Contact:	linux-trace-kernel@vger.kernel.org
Description:

	The ftrace was first added to the kernel, its interface was placed
	into the debugfs file system under the "tracing" directory. Access
	to the files were in /sys/kernel/debug/tracing. As systems wanted
	access to the tracing interface without having to enable debugfs, a
	new interface was created called "tracefs". This was a stand alone
	file system and was usually mounted in /sys/kernel/tracing.

	To allow older tooling to continue to operate, when mounting
	debugfs, the tracefs file system would automatically get mounted in
	the "tracing" directory of debugfs. The tracefs interface was added
	in January 2015 in the v4.1 kernel.

	All tooling should now be using tracefs directly and the "tracing"
	directory in debugfs should be removed by January 2030.