On Tue, Jun 17, 2025 at 11:00 AM Peter Zijlstra <pet...@infradead.org> wrote: > > On Tue, Jun 17, 2025 at 01:54:46PM -0400, Steven Rostedt wrote: > > > > > > On June 17, 2025 1:41:07 PM EDT, Peter Zijlstra <pet...@infradead.org> > > wrote: > > >On Tue, Jun 17, 2025 at 01:36:14PM -0400, Steven Rostedt wrote: > > >> From: Steven Rostedt <rost...@goodmis.org> > > >> > > >> 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. > > If I have to edit the mount table, I'll just keep it at /debug/tracing/. > Tracing is very much debug stuff anyway. While I knew there was tracefs, > I never knew there was another mount point. > > Just annoying I now have to add two entries to every new machine.. Oh > well.
It seems cleaning this up is a good thing wrt permission issues. On my local debian derived machine: ``` $ ls /sys/kernel/debug/tracing/events ls: cannot access '/sys/kernel/debug/tracing/events': Permission denied $ ls /sys/kernel/tracing/events alarmtimer fib irq nmi sunrpc ... ``` I see a number of references to debug/tracing in places like perf testing: https://web.git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/tests/shell/common/init.sh?h=perf-tools-next#n122 are you planning patches for these? Thanks, Ian
