Messages in this thread | | | Date | Thu, 27 Aug 2009 15:35:02 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH] perf: remove PERF_SAMPLE_RAW |
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On Thu, Aug 27, 2009 at 10:43:21AM +0200, Ingo Molnar wrote: > * Peter Zijlstra <peterz@infradead.org> wrote: > > > Apparently people think trace-events became an ABI the moment perf > > exported them, regardless what the text surrounding > > PERF_SAMPLE_RAW said about the opaqueness of the data provided. > > Well it's still opaque and the descriptor of what it means is in > debugfs so it's not an ABI as the comment says. > > > I'm not willing to make anything trace related into an ABI, hence > > remove this. > > This removes quite a bit of nice functionality we already have, so i > think it's (way) too heavy handed. > > I think what we want is the golden middle: a per tracepoint > property. I.e. we would provide: > > TRACE_EVENT_STABLE() > > or TRACE_EVENT_CORE() or TRACE_EVENT_ABI() - which carries a 'will > maintain this as an ABI' promise from the maintainer who adds it.
Why? The format files stand to avoid that.
I don't understand this debate.
> Also, tracepoints are a unidirectional channel of information - in > practice those are way easier to handle as an ABI than other ABIs > such as behavior, semantics, etc. So i'd expect there to be a > healthy set of 'stable' tracepoints. > > Ingo
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