Re: [PATCH v6 06/10] perf metricgroup: Fix metrics using aliases covering multiple PMUs

[Arnaldo Carvalho de Melo]

Em Fri, Dec 04, 2020 at 07:10:12PM +0800, John Garry escreveu:
> Support for metric expressions using aliases which cover multiple PMUs is
> broken. Consider the following test metric expression:
> 
> "MetricExpr": "UNC_CBO_XSNP_RESPONSE.MISS_XCORE * UNC_CBO_XSNP_RESPONSE.MISS_EVICTION"
> 
> When used on my broadwell, "perf stat" gives:
> 
> unc_cbo_xsnp_response.miss_eviction -> uncore_cbox_1/umask=0x81,event=0x22/
> unc_cbo_xsnp_response.miss_eviction -> uncore_cbox_0/umask=0x81,event=0x22/
> unc_cbo_xsnp_response.miss_xcore -> uncore_cbox_1/umask=0x41,event=0x22/
> unc_cbo_xsnp_response.miss_xcore -> uncore_cbox_0/umask=0x41,event=0x22/
> Control descriptor is not initialized
> unc_cbo_xsnp_response.miss_eviction: 3645925 1000850523 1000850523
> unc_cbo_xsnp_response.miss_xcore: 106850 1000850523 1000850523
> 
>  Performance counter stats for 'system wide':
> 
>          3,645,925      unc_cbo_xsnp_response.miss_eviction # 389567086250.00 test_metric_inc
>            106,850      unc_cbo_xsnp_response.miss_xcore
> 
>        1.000883096 seconds time elapsed
> 
> 
> Notice that only the results from one PMU are included. Fix the logic of
> find_evsel_group() to enable events which apply to multiple PMUs, by
> checking if the event pmu_name matches that of the metric event.
> 
> With that, "perf stat" now gives:
> 
> unc_cbo_xsnp_response.miss_eviction -> uncore_cbox_1/umask=0x81,event=0x22/
> unc_cbo_xsnp_response.miss_eviction -> uncore_cbox_0/umask=0x81,event=0x22/
> unc_cbo_xsnp_response.miss_xcore -> uncore_cbox_1/umask=0x41,event=0x22/
> unc_cbo_xsnp_response.miss_xcore -> uncore_cbox_0/umask=0x41,event=0x22/
> Control descriptor is not initialized
> unc_cbo_xsnp_response.miss_eviction: 4237983 1000904100 1000904100
> unc_cbo_xsnp_response.miss_xcore: 218643 1000904100 1000904100
> unc_cbo_xsnp_response.miss_eviction: 4254148 1000902629 1000902629
> unc_cbo_xsnp_response.miss_xcore: 213352 1000902629 1000902629
> 
>  Performance counter stats for 'system wide':
> 
>          4,237,983      unc_cbo_xsnp_response.miss_eviction # 3668558131345.00 test_metric_inc
>            218,643      unc_cbo_xsnp_response.miss_xcore
>          4,254,148      unc_cbo_xsnp_response.miss_eviction
>            213,352      unc_cbo_xsnp_response.miss_xcore
> 
>        1.000938151 seconds time elapsed
> 

Next time please try to provides a Fixes: tag to help with
backporting/stable@xxxxxxxxxx work.

- Arnaldo
 
> Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
> Acked-by: Kajol Jain <kjain@xxxxxxxxxxxxx>
> ---
>  tools/perf/util/metricgroup.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index 81d201c8b833..b89160718c04 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -279,7 +279,9 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist,
>  			 * when then group is left.
>  			 */
>  			if (!has_constraint &&
> -			    ev->leader != metric_events[i]->leader)
> +			    ev->leader != metric_events[i]->leader &&
> +			    !strcmp(ev->leader->pmu_name,
> +				    metric_events[i]->leader->pmu_name))
>  				break;
>  			if (!strcmp(metric_events[i]->name, ev->name)) {
>  				set_bit(ev->idx, evlist_used);
> -- 
> 2.26.2
> 

-- 

- Arnaldo