| 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. |
