1*9ba817fbSSteven RostedtWhat: /sys/kernel/debug/tracing 2*9ba817fbSSteven RostedtDate: May 2008 3*9ba817fbSSteven RostedtKernelVersion: 2.6.27 4*9ba817fbSSteven RostedtContact: linux-trace-kernel@vger.kernel.org 5*9ba817fbSSteven RostedtDescription: 6*9ba817fbSSteven Rostedt 7*9ba817fbSSteven Rostedt The ftrace was first added to the kernel, its interface was placed 8*9ba817fbSSteven Rostedt into the debugfs file system under the "tracing" directory. Access 9*9ba817fbSSteven Rostedt to the files were in /sys/kernel/debug/tracing. As systems wanted 10*9ba817fbSSteven Rostedt access to the tracing interface without having to enable debugfs, a 11*9ba817fbSSteven Rostedt new interface was created called "tracefs". This was a stand alone 12*9ba817fbSSteven Rostedt file system and was usually mounted in /sys/kernel/tracing. 13*9ba817fbSSteven Rostedt 14*9ba817fbSSteven Rostedt To allow older tooling to continue to operate, when mounting 15*9ba817fbSSteven Rostedt debugfs, the tracefs file system would automatically get mounted in 16*9ba817fbSSteven Rostedt the "tracing" directory of debugfs. The tracefs interface was added 17*9ba817fbSSteven Rostedt in January 2015 in the v4.1 kernel. 18*9ba817fbSSteven Rostedt 19*9ba817fbSSteven Rostedt All tooling should now be using tracefs directly and the "tracing" 20*9ba817fbSSteven Rostedt directory in debugfs should be removed by January 2030. 21