Re: [RFC][PATCH] tracing: Deprecate auto-mounting tracefs in debugfs

[Steven Rostedt]

On June 17, 2025 1:41:07 PM EDT, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>On Tue, Jun 17, 2025 at 01:36:14PM -0400, Steven Rostedt wrote:
>> From: Steven Rostedt <rostedt@xxxxxxxxxxx>
>> 
>> In January 2015, tracefs was created to allow access to the tracing
>> infrastructure without needing to compile in debugfs. When tracefs is
>> configured, the directory /sys/kernel/tracing will exist and tooling is
>> expected to use that path to access the tracing infrastructure.
>> 
>> To allow backward compatibility, when debugfs is mounted, it would
>> automount tracefs in its "tracing" directory so that tooling that had hard
>> coded /sys/kernel/debug/tracing would still work.
>> 
>> It has been over 10 years since the new interface was introduced, and all
>> tooling should now be using it. Start the process of deprecating the old
>> path so that it doesn't need to be maintained anymore.
>
>I've always used /debug/tracing/ (because /debug is the right place to
>mount debugfs). You're saying this is going away and will break all my
>scripts?!

You could mount tracefs in /tracing too:

  # mount -t tracefs nodev /tracing 

And update you scripts with a simple sed script.

-- Steve