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

[Peter Zijlstra]

On Wed, Jun 18, 2025 at 09:21:02AM +0200, Sebastian Andrzej Siewior wrote:
> On 2025-06-17 20:00:23 [+0200], Peter Zijlstra wrote:
> > 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.
> 
> I don't know what you run but since Debian 11/ Bullseye (v5.10) this happens
> more or less on its own. systemd has the proper mount units:
> | # mount | grep trace
> | tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
> | # ls -lh /sys/kernel/debug/tracing/ > /dev/null
> | # mount | grep trace
> | tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
> | tracefs on /sys/kernel/debug/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
> 
> This of course doesn't work if you manually mount it to /debug. While a
> symlink would work, you still have to touch the boxes.

Mostly debian/testing. I prefer a mount from /etc/fstab, I tried a
symlink once but that is weird with tab completion for some reason.