[PATCH] tools/perf: Add check to tool pmu tests to ensure if the event is valid

[Athira Rajeev]

"Tool PMU" tests fails on powerpc as below:

   12.1: Parsing without PMU name:
   --- start ---
   test child forked, pid 48492
   Using CPUID 0x00800200
   Attempt to add: tool/duration_time/
   ..after resolving event: tool/config=0x1/
   duration_time -> tool/duration_time/
   Attempt to add: tool/user_time/
   ..after resolving event: tool/config=0x2/
   user_time -> tool/user_time/
   Attempt to add: tool/system_time/
   ..after resolving event: tool/config=0x3/
   system_time -> tool/system_time/
   Attempt to add: tool/has_pmem/
   ..after resolving event: tool/config=0x4/
   has_pmem -> tool/has_pmem/
   Attempt to add: tool/num_cores/
   ..after resolving event: tool/config=0x5/
   num_cores -> tool/num_cores/
   Attempt to add: tool/num_cpus/
   ..after resolving event: tool/config=0x6/
   num_cpus -> tool/num_cpus/
   Attempt to add: tool/num_cpus_online/
   ..after resolving event: tool/config=0x7/
   num_cpus_online -> tool/num_cpus_online/
   Attempt to add: tool/num_dies/
   ..after resolving event: tool/config=0x8/
   num_dies -> tool/num_dies/
   Attempt to add: tool/num_packages/
   ..after resolving event: tool/config=0x9/
   num_packages -> tool/num_packages/

   ---- unexpected signal (11) ----
   12.1: Parsing without PMU name                                      : FAILED!

Same fail is observed for "Parsing with PMU name" as well.

The testcase loops through events in tool_pmu__for_each_event()
and access event name using "tool_pmu__event_to_str()".
Here tool_pmu__event_to_str returns null for "slots" event
and "system_tsc_freq" event. These two events are only applicable
for arm64 and x86 respectively. So the function tool_pmu__event_to_str()
skips for unsupported events and returns null. This null value is
causing testcase fail.

To address this in "Tool PMU" testcase, add a helper function
tool_pmu__all_event_to_str() which returns the name for all
events mapping to the tool_pmu_event index including the
skipped ones. So that even if its a skipped event, the
helper function helps to resolve the tool_pmu_event index to
its mapping event name. Update the testcase to check for null event
names before proceeding the test.

Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
---
 tools/perf/tests/tool_pmu.c | 12 ++++++++++++
 tools/perf/util/tool_pmu.c  | 17 +++++++++++++++++
 tools/perf/util/tool_pmu.h  |  1 +
 3 files changed, 30 insertions(+)

diff --git a/tools/perf/tests/tool_pmu.c b/tools/perf/tests/tool_pmu.c
index 187942b749b7..e468e5fb3c73 100644
--- a/tools/perf/tests/tool_pmu.c
+++ b/tools/perf/tests/tool_pmu.c
@@ -19,6 +19,18 @@ static int do_test(enum tool_pmu_event ev, bool with_pmu)
 		return TEST_FAIL;
 	}
 
+	/*
+	 * if tool_pmu__event_to_str returns NULL, Check if the event is
+	 * valid for the platform.
+	 * Example:
+	 * slots event is only on arm64.
+	 * system_tsc_freq event is only on x86.
+	 */
+	if (!tool_pmu__event_to_str(ev) && tool_pmu__skip_event(tool_pmu__all_event_to_str(ev))) {
+		ret = TEST_OK;
+		goto out;
+	}
+
 	if (with_pmu)
 		snprintf(str, sizeof(str), "tool/%s/", tool_pmu__event_to_str(ev));
 	else
diff --git a/tools/perf/util/tool_pmu.c b/tools/perf/util/tool_pmu.c
index 3a68debe7143..572422797f6e 100644
--- a/tools/perf/util/tool_pmu.c
+++ b/tools/perf/util/tool_pmu.c
@@ -60,6 +60,15 @@ int tool_pmu__num_skip_events(void)
 	return num;
 }
 
+/*
+ * tool_pmu__event_to_str returns only supported event names.
+ * For events which are supposed to be skipped in the platform,
+ * return NULL
+ *
+ * tool_pmu__all_event_to_str returns the name for all
+ * events mapping to the tool_pmu_event index including the
+ * skipped ones.
+ */
 const char *tool_pmu__event_to_str(enum tool_pmu_event ev)
 {
 	if ((ev > TOOL_PMU__EVENT_NONE && ev < TOOL_PMU__EVENT_MAX) &&
@@ -69,6 +78,14 @@ const char *tool_pmu__event_to_str(enum tool_pmu_event ev)
 	return NULL;
 }
 
+const char *tool_pmu__all_event_to_str(enum tool_pmu_event ev)
+{
+	if (ev > TOOL_PMU__EVENT_NONE && ev < TOOL_PMU__EVENT_MAX)
+		return tool_pmu__event_names[ev];
+
+	return NULL;
+}
+
 enum tool_pmu_event tool_pmu__str_to_event(const char *str)
 {
 	int i;
diff --git a/tools/perf/util/tool_pmu.h b/tools/perf/util/tool_pmu.h
index a60184859080..da76808ae71e 100644
--- a/tools/perf/util/tool_pmu.h
+++ b/tools/perf/util/tool_pmu.h
@@ -30,6 +30,7 @@ enum tool_pmu_event {
 	for ((ev) = TOOL_PMU__EVENT_DURATION_TIME; (ev) < TOOL_PMU__EVENT_MAX; ev++)
 
 const char *tool_pmu__event_to_str(enum tool_pmu_event ev);
+const char *tool_pmu__all_event_to_str(enum tool_pmu_event ev);
 enum tool_pmu_event tool_pmu__str_to_event(const char *str);
 bool tool_pmu__skip_event(const char *name);
 int tool_pmu__num_skip_events(void);
-- 
2.43.5