[PATCH 2/2] perf tests: Add a test case for checking sw clock event frequency

Namhyung Kim
2013-03-18T02:42:10Z

From: Namhyung Kim <namhyung.kim@lge.com>

This test case checks frequency conversion of hrtimer-based software
clock events (cpu-clock, task-clock) have valid (non-1) periods.

Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/Makefile | 1 +
tools/perf/tests/builtin-test.c | 4 ++
tools/perf/tests/sw-clock.c | 118 ++++++++++++++++++++++++++++++++++++++++
tools/perf/tests/tests.h | 1 +
4 files changed, 124 insertions(+)
create mode 100644 tools/perf/tests/sw-clock.c

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 8e1bba35a1ee..0230b75ed7f9 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -514,6 +514,7 @@ LIB_OBJS += $(OUTPUT)tests/python-use.o
LIB_OBJS += $(OUTPUT)tests/bp_signal.o
LIB_OBJS += $(OUTPUT)tests/bp_signal_overflow.o
LIB_OBJS += $(OUTPUT)tests/task-exit.o
+LIB_OBJS += $(OUTPUT)tests/sw-clock.o

BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 9b5c70a180d2..0918ada4cc41 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -90,6 +90,10 @@ static struct test {
.func = test__task_exit,
},
{
+ .desc = "Test software clock events have valid period values",
+ .func = test__sw_clock_freq,
+ },
+ {
.func = NULL,
},
};
diff --git a/tools/perf/tests/sw-clock.c b/tools/perf/tests/sw-clock.c
new file mode 100644
index 000000000000..a45d72618096
--- /dev/null
+++ b/tools/perf/tests/sw-clock.c
@@ -0,0 +1,118 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/mman.h>
+
+#include "tests.h"
+#include "util/evsel.h"
+#include "util/evlist.h"
+#include "util/cpumap.h"
+#include "util/thread_map.h"
+
+#define NR_LOOPS 1000000
+
+/*
+ * This test will open software clock events (cpu-clock, task-clock)
+ * then check their frequency -> period conversion has no artifact of
+ * setting period to 1 forcefully.
+ */
+static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
+{
+ int i, err = -1;
+ volatile int tmp = 0;
+ u64 total_periods = 0;
+ int nr_samples = 0;
+ union perf_event *event;
+ struct perf_evsel *evsel;
+ struct perf_evlist *evlist;
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_SOFTWARE,
+ .config = clock_id,
+ .sample_type = PERF_SAMPLE_PERIOD,
+ .exclude_kernel = 1,
+ .disabled = 1,
+ .freq = 1,
+ .sample_freq = 10000,
+ };
+
+ evlist = perf_evlist__new();
+ if (evlist == NULL) {
+ pr_debug("perf_evlist__new\n");
+ return -1;
+ }
+
+ evsel = perf_evsel__new(&attr, 0);
+ if (evsel == NULL) {
+ pr_debug("perf_evsel__new\n");
+ goto out_free_evlist;
+ }
+ perf_evlist__add(evlist, evsel);
+
+ evlist->cpus = cpu_map__dummy_new();
+ evlist->threads = thread_map__new_by_tid(getpid());
+ if (!evlist->cpus || !evlist->threads) {
+ err = -ENOMEM;
+ pr_debug("Not enough memory to create thread/cpu maps\n");
+ goto out_delete_maps;
+ }
+
+ perf_evlist__open(evlist);
+
+ err = perf_evlist__mmap(evlist, 128, true);
+ if (err < 0) {
+ pr_debug("failed to mmap event: %d (%s)\n", errno,
+ strerror(errno));
+ goto out_close_evlist;
+ }
+
+ perf_evlist__enable(evlist);
+
+ /* collect samples */
+ for (i = 0; i < NR_LOOPS; i++)
+ tmp++;
+
+ perf_evlist__disable(evlist);
+
+ while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
+ struct perf_sample sample;
+
+ if (event->header.type != PERF_RECORD_SAMPLE)
+ continue;
+
+ err = perf_evlist__parse_sample(evlist, event, &sample);
+ if (err < 0) {
+ pr_debug("Error during parse sample\n");
+ goto out_unmap_evlist;
+ }
+
+ total_periods += sample.period;
+ nr_samples++;
+ }
+
+ if ((u64) nr_samples == total_periods) {
+ pr_debug("All (%d) samples have period value of 1!\n",
+ nr_samples);
+ err = -1;
+ }
+
+out_unmap_evlist:
+ perf_evlist__munmap(evlist);
+out_close_evlist:
+ perf_evlist__close(evlist);
+out_delete_maps:
+ perf_evlist__delete_maps(evlist);
+out_free_evlist:
+ perf_evlist__delete(evlist);
+ return err;
+}
+
+int test__sw_clock_freq(void)
+{
+ int ret;
+
+ ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
+ if (!ret)
+ ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);
+
+ return ret;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index b33b3286ad6e..dd7feae2d37b 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -26,5 +26,6 @@ int test__python_use(void);
int test__bp_signal(void);
int test__bp_signal_overflow(void);
int test__task_exit(void);
+int test__sw_clock_freq(void);

#endif /* TESTS_H */
--
1.7.11.7