On Wed, 31 Jan 2024 13:00:39 -0500 Steven Rostedt <rost...@goodmis.org> wrote:
> On Tue, 30 Jan 2024 11:03:55 -0800 > Linus Torvalds <torva...@linux-foundation.org> wrote: > > > It would probably be cleaner to make eventfs its own filesystem, or at > > least set its own dentry ops when looking up eventfs files. But as it > > is, only eventfs dentries use d_fsdata, so we don't really need to split > > these things up by use. > > BTW, I have been thinking about making eventfs a completely separate file > system that could be mounted outside of tracefs. One that is readonly that > only contains the "id" and "format" files and nothing more. > > Why? Because perf and powertop both use those files to know how to parse > the raw event formats. I don't think there's anything in there that > requires root privileges to read. They should not be exposing any internal > kernel information besides the event format layouts, and it would be nice > to have a /sys/kernel/events directory that only had that. That's a good idea! So maybe we can allow perf to read it without root user. > > Making eventfs a separate file system where, when added to tracefs, has the > control files for the specific trace_array, but for the /sys/kernel > directory, only cares about the trace format files. > > Then tracefs could be nicely converted over to kernfs, and eventfs would be > its own entity. If so, maybe we can just make symlinks to the 'id' and 'format' from events under tracefs? :) Thank you, > > -- Steve -- Masami Hiramatsu (Google) <mhira...@kernel.org>
