Notes from the LPC scheduler microconference

That's an interesting approach. I certainly think it has the merit of being discussed.

But from my point of view, they should all be seen as "can go away at any time". I would think that that should it make more palatable for maintainers to accept them -- and easier to garbage-collect them at any time. I bet it's even possible to create a script that allows user-space-tool-maintainers to identify trace point deltas from one version to the next and adjust their code accordingly.

Still, I see your point. In fact, that's the point I argued on the LKML circa 2005/2006 when I was still getting pushback on the LTT patches. I essentially showed that the trace points I had in 1999 and 2005/6 were essentially the same set and, hence, the whole argument about unmaintainability was overblown. IOW, some events are always going to take place in any Unix-like kernel: system calls, sched changes, interrupt entries, etc.

It's a good argument for having the trace points part of the sources. It doesn't mean they should be considered ABI. In fact, trace points are likely closer to the driver API than the system call API in terms of long-term consistency guarantees. The former can change at any time, the latter never should.