perf test: Avoid sysfs state affecting fake events

Icelake has a slots event, on my Skylakex I have CPU events in sysfs of
topdown-slots-issued and topdown-total-slots.

Legacy event parsing would try to use '-' to separate parts of an event
and so perf_pmu__parse_init sets 'slots' to be a
PMU_EVENT_SYMBOL_SUFFIX2.

As such parsing the slots event for a fake PMU fails as a
PMU_EVENT_SYMBOL_SUFFIX2 isn't made into the PE_PMU_EVENT_FAKE token.

Resolve this issue by test initializing the PMU parsing state before
every parse. This must be done every parse as the state is removes after
each parse_events.

Signed-off-by: Ian Rogers <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Caleb Biggers <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Kshipra Bopardikar <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Maxime Coquelin <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Perry Taylor <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sedat Dilek <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Xing Zhengjun <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 9 insertions, 0 deletions

diff --git a/tools/perf/tests/pmu-events.c b/tools/perf/tests/pmu-events.c
index 478b33825790..263cbb67c861 100644
--- a/tools/perf/tests/pmu-events.c
+++ b/tools/perf/tests/pmu-events.c
@@ -812,6 +812,15 @@ static int check_parse_id(const char *id, struct parse_events_error *error,
 	for (cur = strchr(dup, '@') ; cur; cur = strchr(++cur, '@'))
 		*cur = '/';
 
+	if (fake_pmu) {
+		/*
+		 * Every call to __parse_events will try to initialize the PMU
+		 * state from sysfs and then clean it up at the end. Reset the
+		 * PMU events to the test state so that we don't pick up
+		 * erroneous prefixes and suffixes.
+		 */
+		perf_pmu__test_parse_init();
+	}
 	ret = __parse_events(evlist, dup, error, fake_pmu);
 	free(dup);