[PATCH 2/2] perf tools/tests: Fix topdown groups test on hybrid platforms

[Dapeng Mi]

When running topdown groups test on hybrid platforms like LNL/ARL, we
see the following 2 commands fail.

perf stat $cputype -e '{instructions,slots},topdown-retiring' true
perf stat $cputype -e '{instructions,slots},{topdown-retiring}' true

Take the 1st command as an example, 5 events are created on hybrid
platform. They are cpu_atom/instructions/, cpu_core/instructions/,
cpu_core/slots/, cpu_atom/topdown-retiring/ and
cpu_core/topdown-retiring/ events. The former 3 events are in a group
and the latter 2 topdown-retiring events are independent events.

As the limitation of current implementation, the
cpu_core/topdown-retiring/ event can't be moved into previous group as
long as there are other events before it. That's the reason why we see
the failure.

Thus add "--cputype core" option to limit only P-core events are tested.

Signed-off-by: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>
---
 tools/perf/arch/x86/util/evlist.c | 26 +++++++++++++++++++++++---
 tools/perf/tests/shell/stat.sh    | 20 ++++++++++++++++++--
 2 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/tools/perf/arch/x86/util/evlist.c b/tools/perf/arch/x86/util/evlist.c
index 447a734e591c..0a71ba975871 100644
--- a/tools/perf/arch/x86/util/evlist.c
+++ b/tools/perf/arch/x86/util/evlist.c
@@ -9,7 +9,7 @@ int arch_evlist__cmp(const struct evsel *lhs, const struct evsel *rhs)
 {
 	/*
 	 * Currently the following topdown events sequence are supported to
-	 * move and regroup correctly.
+	 * move and regroup correctly on non-hybrid platforms.
 	 *
 	 * a. all events in a group
 	 *    perf stat -e "{instructions,topdown-retiring,slots}" -C0 sleep 1
@@ -44,7 +44,7 @@ int arch_evlist__cmp(const struct evsel *lhs, const struct evsel *rhs)
 	 * 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
+	 * e. 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
@@ -56,11 +56,31 @@ int arch_evlist__cmp(const struct evsel *lhs, const struct evsel *rhs)
 	 * 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
+	 * f. perf stat -e "{instructions,slots},{topdown-retiring,cycles}" -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)
+	 *
+	 * For hybrid platforms, the sequences 'c' and 'd' are not supported as well
+	 * besides above sequences 'e' and 'f'.
+	 *
+	 *    perf stat -e "{instructions,slots},topdown-retiring" -C0 sleep 1
+	 *    perf stat -e "{instructions,slots},{topdown-retiring}" -C0 sleep 1
+	 *
+	 * On hybrid platforms each event would create an instance on all types of PMU
+	 * if the event can be supported by the PMU, i.e., the "topdown-retiring" event
+	 * would create two instances on hybrid platforms with P-cores and E-cores,
+	 * "cpu_core/topdown-retiring/" and "cpu_atom/topdown_retiring".
+	 *
+	 * Take the first command as an example, the events list would be converted to
+	 * below list in fact.
+	 *
+	 * "{cpu_atom/instructions/,cpu_core/instructions/,cpu_core/slots/},
+	 *  cpu_atom/topdown-retiring/,cpu_core/topdown-retiring/"
+	 *
+	 * This is actually same with event list in case 'e', "cpu_core/topdown-retiring/"
+	 * event can't be moved into previous events group.
 	 */
 	if (topdown_sys_has_perf_metrics() &&
 	    (arch_evsel__must_be_in_group(lhs) || arch_evsel__must_be_in_group(rhs))) {
diff --git a/tools/perf/tests/shell/stat.sh b/tools/perf/tests/shell/stat.sh
index 68323d636fb7..cdfe27c25528 100755
--- a/tools/perf/tests/shell/stat.sh
+++ b/tools/perf/tests/shell/stat.sh
@@ -5,6 +5,16 @@
 set -e
 
 err=0
+is_hybrid=false
+
+check_hybrid_platform() {
+  pmus=$(ls /sys/bus/event_source/devices/*/cpus 2>/dev/null | wc -l)
+  if [ "$pmus" -gt 1 ]
+  then
+    is_hybrid=true
+  fi
+}
+
 test_default_stat() {
   echo "Basic stat command test"
   if ! perf stat true 2>&1 | grep -E -q "Performance counter stats for 'true':"
@@ -62,6 +72,11 @@ test_topdown_groups() {
   # Topdown events must be grouped with the slots event first. Test that
   # parse-events reorders this.
   echo "Topdown event group test"
+  cputype=""
+  if $is_hybrid
+  then
+    cputype="--cputype core"
+  fi
   if ! perf stat -e '{slots,topdown-retiring}' true > /dev/null 2>&1
   then
     echo "Topdown event group test [Skipped event parsing failed]"
@@ -85,13 +100,13 @@ test_topdown_groups() {
     err=1
     return
   fi
-  if perf stat -e '{instructions,slots},topdown-retiring' true 2>&1 | grep -E -q "<not supported>"
+  if perf stat $cputype -e '{instructions,slots},topdown-retiring' true 2>&1 | grep -E -q "<not supported>"
   then
     echo "Topdown event group test [Failed topdown metrics event not move into slots group]"
     err=1
     return
   fi
-  if perf stat -e '{instructions,slots},{topdown-retiring}' true 2>&1 | grep -E -q "<not supported>"
+  if perf stat $cputype -e '{instructions,slots},{topdown-retiring}' true 2>&1 | grep -E -q "<not supported>"
   then
     echo "Topdown event group test [Failed topdown metrics group not merge into slots group]"
     err=1
@@ -200,6 +215,7 @@ test_hybrid() {
   echo "hybrid test [Success]"
 }
 
+check_hybrid_platform
 test_default_stat
 test_stat_record_report
 test_stat_record_script
-- 
2.40.1