[PATCH] perf parse-events: Do not break up AUX event group

[Adrian Hunter]

Assume AUX event group is correct and not do break it up.

Example:

 Before:

    $ perf record --no-bpf-event -c 10 -e '{intel_pt//,tlb_flush.stlb_any/aux-sample-size=8192/pp}:u' -- sleep 0.1
    WARNING: events were regrouped to match PMUs
    Cannot add AUX area sampling to a group leader

 After:

    $ perf record --no-bpf-event -c 10 -e '{intel_pt//,tlb_flush.stlb_any/aux-sample-size=8192/pp}:u' -- sleep 0.1
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.078 MB perf.data ]
    $ perf script -F-dso,+addr | grep -C5 tlb_flush.stlb_any | head -11
    sleep 20444 [003]  7939.510243:  1  branches:uH:  7f5350cc82a2 dl_main+0x9a2 => 7f5350cb38f0 _dl_add_to_namespace_list+0x0
    sleep 20444 [003]  7939.510243:  1  branches:uH:  7f5350cb3908 _dl_add_to_namespace_list+0x18 => 7f5350cbb080 rtld_mutex_dummy+0x0
    sleep 20444 [003]  7939.510243:  1  branches:uH:  7f5350cc8350 dl_main+0xa50 => 0 [unknown]
    sleep 20444 [003]  7939.510244:  1  branches:uH:  7f5350cc83ca dl_main+0xaca => 7f5350caeb60 _dl_process_pt_gnu_property+0x0
    sleep 20444 [003]  7939.510245:  1  branches:uH:  7f5350caeb60 _dl_process_pt_gnu_property+0x0 => 0 [unknown]
    sleep 20444  7939.510245:       10 tlb_flush.stlb_any/aux-sample-size=8192/pp: 0 7f5350caeb60 _dl_process_pt_gnu_property+0x0
    sleep 20444 [003]  7939.510254:  1  branches:uH:  7f5350cc87fe dl_main+0xefe => 7f5350ccd240 strcmp+0x0
    sleep 20444 [003]  7939.510254:  1  branches:uH:  7f5350cc8862 dl_main+0xf62 => 0 [unknown]
    sleep 20444 [003]  7939.510255:  1  branches:uH:  7f5350cc9cdc dl_main+0x23dc => 0 [unknown]
    sleep 20444 [003]  7939.510257:  1  branches:uH:  7f5350cc89f6 dl_main+0x10f6 => 7f5350cb9530 _dl_setup_hash+0x0
    sleep 20444 [003]  7939.510257:  1  branches:uH:  7f5350cc8a2d dl_main+0x112d => 7f5350cb3990 _dl_new_object+0x0

Fixes: 347c2f0a0988 ("perf parse-events: Sort and group parsed events")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 tools/perf/util/evsel.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 356c07f03be6..a34f61a5271d 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -828,7 +828,11 @@ bool evsel__name_is(struct evsel *evsel, const char *name)
 
 const char *evsel__group_pmu_name(const struct evsel *evsel)
 {
-	const struct evsel *leader;
+	const struct evsel *leader = evsel__leader(evsel);
+
+	/* Never break AUX event groups */
+	if (evsel__is_aux_event(leader))
+		return leader->pmu_name;
 
 	/* If the pmu_name is set use it. pmu_name isn't set for CPU and software events. */
 	if (evsel->pmu_name)
@@ -837,15 +841,9 @@ const char *evsel__group_pmu_name(const struct evsel *evsel)
 	 * Software events may be in a group with other uncore PMU events. Use
 	 * the pmu_name of the group leader to avoid breaking the software event
 	 * out of the group.
-	 *
-	 * Aux event leaders, like intel_pt, expect a group with events from
-	 * other PMUs, so substitute the AUX event's PMU in this case.
 	 */
-	leader  = evsel__leader(evsel);
-	if ((evsel->core.attr.type == PERF_TYPE_SOFTWARE || evsel__is_aux_event(leader)) &&
-	    leader->pmu_name) {
+	if (evsel->core.attr.type == PERF_TYPE_SOFTWARE && leader->pmu_name)
 		return leader->pmu_name;
-	}
 
 	return "cpu";
 }
-- 
2.34.1