Re: [PATCH 1/2] perf script: Skip aggregation for stat events

From: Arnaldo Carvalho de Melo
Date: Wed May 10 2023 - 13:37:48 EST


Em Fri, May 05, 2023 at 04:43:20PM -0700, Namhyung Kim escreveu:
> Hello,
>
> On Fri, May 5, 2023 at 3:03 AM Sandipan Das <sandipan.das@xxxxxxx> wrote:
> >
> > The script command does not support aggregation modes by itself although
> > that can be achieved using post-processing scripts. Because of this, it
> > does not allocate memory for aggregated event values.
> >
> > Upon running perf stat record, the aggregation mode is set in the perf
> > data file. If the mode is AGGR_GLOBAL, the aggregated event values are
> > accessed and this leads to a segmentation fault since these were never
> > allocated to begin with. Set the mode to AGGR_NONE explicitly to avoid
> > this.
> >
> > E.g.
> >
> > $ perf stat record -e cycles true
> > $ perf script
> >
> > Before:
> > Segmentation fault (core dumped)
> >
> > After:
> > CPU THREAD VAL ENA RUN TIME EVENT
> > -1 231919 162831 362069 362069 935289 cycles:u
> >
> > Fixes: 8b76a3188b85 ("perf stat: Remove unused perf_counts.aggr field")
> > Signed-off-by: Sandipan Das <sandipan.das@xxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx # v6.2+
>
> Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Thanks, applied both to perf-tools, for v6.4.

- Arnaldo