Re: [PATCH V3 20/37] perf script: Add 'synth' event type for synthesized events

From: Arnaldo Carvalho de Melo
Date: Thu Jun 22 2017 - 10:59:42 EST


Em Wed, Jun 21, 2017 at 11:20:03PM +0300, Adrian Hunter escreveu:
> On 06/21/2017 08:29 PM, Arnaldo Carvalho de Melo wrote:
> > Em Wed, Jun 21, 2017 at 07:41:04PM +0300, Adrian Hunter escreveu:
> >> PERF_TYPE_ is dynamically allocated above PERF_TYPE_MAX for PMUs. Presently
> >> perf_pmu_register() calls idr_alloc() with end=0 which limits the allocation
> >> to INT_MAX.

> > Oh, forgot about that, guess a comment right beside PERF_TYPE_MAX is in
> > demand :-\

> > So why not:

> > /*
> > * PERF_TYPE_ is dynamically allocated above PERF_TYPE_MAX for PMUs. Presently
> > * perf_pmu_register() calls idr_alloc() with end=0 which limits the allocation
> > * to INT_MAX.
> > */
> > #define PERF_TYPE_SYNTH (INT_MAX + 1L)

> > I.e. wouldn't be some arbitrarily huge value, but one right after what
> > was defined as the area for the dynamicly allocated PERF_TYPE_
> > "namespace" for PMUs, right?

> That seems fine. Pedantically it should be (INT_MAX + 1U) otherwise it will
> be negative on a 32-bit system.

oh, not pedantic at all, thanks for the fix, will update your patch and
continue from there, Ingo already pulled everything up to this point,
btw.

- Arnaldo