Re: [PATCH V2 2/2] perf tools: always set no branch for dummy event in PT
From: Arnaldo Carvalho de Melo
Date: Mon Jul 03 2017 - 12:59:29 EST
Em Mon, Jul 03, 2017 at 09:58:32AM +0200, Jiri Olsa escreveu:
> On Fri, Jun 30, 2017 at 10:16:56AM -0400, kan.liang@xxxxxxxxx wrote:
> > From: Kan Liang <kan.liang@xxxxxxxxx>
> > An earlier kernel patch allowed enabling PT and LBR at the same time on
> > Goldmont.
> > commit ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity
> > if the core supports it")
> > However, users still cannot use Intel PT and LBRs simultaneously.
> > $ sudo perf record -e cycles,intel_pt//u -b -- sleep 1
> > Error:
> > PMU Hardware doesn't support sampling/overflow-interrupts.
> > PT implicitly adds dummy event in perf tool. dummy event is software
> > event which doesn't support LBR.
> > Always setting no branch for dummy event in Intel PT.
> > Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
> for the patchset:
> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>