Re: PATCH [0/4] perf: clean-up of power events API

Ingo Molnar
2010-10-19T11:52:00Z

* Peter Zijlstra <peterz@infradead.org> wrote:

> On Tue, 2010-10-19 at 13:45 +0200, Ingo Molnar wrote:
> >
> > * Thomas Renninger <trenn@suse.de> wrote:
> >
> > > > Most definitely. It's no accident that it took such a long time for this issue
> > > > to be raised in the first place. It's a rare occurance -
> > >
> > > Do you agree that this occurance happened now and these events should get cleaned
> > > up before ARM and other archs make use of the broken interface?
> > >
> > > If not, discussing this further, is a big waste of time... and Jean would have to
> > > try to adapt his ARM code on the broken ABI...
> >
> > The discussion seems to have died down somewhat. Please re-send to lkml the latest
> > patches you have to remind everyone of the latest state of things - the merge window
> > is getting near.
> >
> > My only compatibility/ABI point is basically that it shouldnt break _existing_
> > tracepoints (and users thereof). If your latest bits meet that then it ought to be a
> > good first step. You are free to (and encouraged to) introduce more complete sets of
> > events.
>
> Can we deprecate and eventually remove the old ones, or will we be forever obliged
> to carry the old ones too?

We most definitely want to deprecate and remove the old ones - but we want to give
instrumentation software some migration time for that.

Jean, Arjan, what would be a feasible and practical deprecation period for that? One
kernel cycle?

Thanks,

Ingo