Re: [PATCH 2/2] perf intel-pt: Fix system_wide dummy event for hybrid

From: Namhyung Kim
Date: Wed Oct 12 2022 - 12:25:31 EST


On Wed, Oct 12, 2022 at 1:23 AM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>
> User space tasks can migrate between CPUs, so when tracing selected CPUs,
> system-wide sideband is still needed, however evlist->core.has_user_cpus
> is not set in the hybrid case, so check the target cpu_list instead.
>
> Fixes: 7d189cadbeeb ("perf intel-pt: Track sideband system-wide when needed")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Thanks,
Namhyung


> ---
> tools/perf/arch/x86/util/intel-pt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
> index 793b35f2221a..af102f471e9f 100644
> --- a/tools/perf/arch/x86/util/intel-pt.c
> +++ b/tools/perf/arch/x86/util/intel-pt.c
> @@ -866,7 +866,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
> * User space tasks can migrate between CPUs, so when tracing
> * selected CPUs, sideband for all CPUs is still needed.
> */
> - need_system_wide_tracking = evlist->core.has_user_cpus &&
> + need_system_wide_tracking = opts->target.cpu_list &&
> !intel_pt_evsel->core.attr.exclude_user;
>
> tracking_evsel = evlist__add_aux_dummy(evlist, need_system_wide_tracking);
> --
> 2.25.1
>