Re: [Ksummit-discuss] [TECH TOPIC] Pulling away from the tracing ABI quicksands

[Linus Torvalds <torvalds@linux-foundation.org>]

On Thu, Jun 29, 2017 at 5:52 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
>
> Just to explain what Mathieu was talking about with echo and such, is
> that Peter Zijlstra has been against multiple tracepoints for that one
> sched switch location.

I am too.

Dammit, if somebody cares about one partiocular scheduler, then that
person can add dynamic tracepoints.

Leave the existing one alone. Really. Zero out any fields that no
longer make sense. Really. Don't beat this damn horse again. It's been
dead for three years, and it's not just smelling bad, it's bloating in
some scary ways.

The only reason for static tracepoints are for major tools like
powertop. There is no way in hell such a tool will care about fields
that only exist for one particular scheduler implementation. Don't add
new random crap.

If somebody is interested in *one* particular odd low-level scheduler,
he damn well can add the dynamic points.

This is the last I want to ever hear about it, and I particularly do
not want to have this be a kernel summit discussion. We've had it
before. Get over it.

                Linus