Re: [PATCH v2 4/5] perf x86 evlist: Update comments on topdown regrouping

[Namhyung Kim]

Hello,

On Thu, Mar 06, 2025 at 06:39:05PM -0800, Ian Rogers wrote:
> From: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
> 
> Update to remove comments about groupings not working and with the:
> ```
> perf stat -e "{instructions,slots},{cycles,topdown-retiring}"
> ```
> case that now works.
> 
> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>

Dapeng, can I get your Signed-off-by here?

Thanks,
Namhyung

> ---
>  tools/perf/arch/x86/util/evlist.c | 27 ++++++---------------------
>  1 file changed, 6 insertions(+), 21 deletions(-)
> 
> diff --git a/tools/perf/arch/x86/util/evlist.c b/tools/perf/arch/x86/util/evlist.c
> index ed205d1b207d..7905a28d7734 100644
> --- a/tools/perf/arch/x86/util/evlist.c
> +++ b/tools/perf/arch/x86/util/evlist.c
> @@ -39,28 +39,13 @@ int arch_evlist__cmp(const struct evsel *lhs, const struct evsel *rhs)
>  	 *         26,319,024      slots
>  	 *          2,427,791      instructions
>  	 *          2,683,508      topdown-retiring
> -	 *
> -	 * If slots event and topdown metrics events are not in same group, the
> -	 * topdown metrics events must be first event after the slots event group,
> -	 * otherwise topdown metrics events can't be regrouped correctly, e.g.
> -	 *
> -	 * a. perf stat -e "{instructions,slots},cycles,topdown-retiring" -C0 sleep 1
> -	 *    WARNING: events were regrouped to match PMUs
> -	 *     Performance counter stats for 'CPU(s) 0':
> -	 *         17,923,134      slots
> -	 *          2,154,855      instructions
> -	 *          3,015,058      cycles
> -	 *    <not supported>      topdown-retiring
> -	 *
> -	 * If slots event and topdown metrics events are in two groups, the group which
> -	 * has topdown metrics events must contain only the topdown metrics event,
> -	 * otherwise topdown metrics event can't be regrouped correctly as well, e.g.
> -	 *
> -	 * a. perf stat -e "{instructions,slots},{topdown-retiring,cycles}" -C0 sleep 1
> +	 * e. slots event and metrics event are in a group and not adjacent
> +	 *    perf stat -e "{instructions,slots},cycles,topdown-retiring" -C0 sleep 1
>  	 *    WARNING: events were regrouped to match PMUs
> -	 *    Error:
> -	 *    The sys_perf_event_open() syscall returned with 22 (Invalid argument) for
> -	 *    event (topdown-retiring)
> +	 *         68,433,522      slots
> +	 *          8,856,102      topdown-retiring
> +	 *          7,791,494      instructions
> +	 *         11,469,513      cycles
>  	 */
>  	if (topdown_sys_has_perf_metrics() &&
>  	    (arch_evsel__must_be_in_group(lhs) || arch_evsel__must_be_in_group(rhs))) {
> -- 
> 2.49.0.rc0.332.g42c0ae87b1-goog
>