[PATCH RFC v5 09/13] perf metricgroup: Fix metrics using aliases covering multiple PMUs

[John Garry]

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


Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 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 060454a17293..da979dd50809 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