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-rw-r--r--tools/perf/tests/sw-clock.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/tools/perf/tests/sw-clock.c b/tools/perf/tests/sw-clock.c
new file mode 100644
index 000000000..1aa21c907
--- /dev/null
+++ b/tools/perf/tests/sw-clock.c
@@ -0,0 +1,124 @@
+#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 10000000
+
+/*
+ * 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;
+ char sbuf[STRERR_BUFSIZE];
+ 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,
+ };
+
+ attr.sample_freq = 500;
+
+ evlist = perf_evlist__new();
+ if (evlist == NULL) {
+ pr_debug("perf_evlist__new\n");
+ return -1;
+ }
+
+ evsel = perf_evsel__new(&attr);
+ if (evsel == NULL) {
+ pr_debug("perf_evsel__new\n");
+ goto out_delete_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_evlist;
+ }
+
+ if (perf_evlist__open(evlist)) {
+ const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";
+
+ err = -errno;
+ pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
+ strerror_r(errno, sbuf, sizeof(sbuf)),
+ knob, (u64)attr.sample_freq);
+ goto out_delete_evlist;
+ }
+
+ err = perf_evlist__mmap(evlist, 128, true);
+ if (err < 0) {
+ pr_debug("failed to mmap event: %d (%s)\n", errno,
+ strerror_r(errno, sbuf, sizeof(sbuf)));
+ goto out_delete_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)
+ goto next_event;
+
+ err = perf_evlist__parse_sample(evlist, event, &sample);
+ if (err < 0) {
+ pr_debug("Error during parse sample\n");
+ goto out_delete_evlist;
+ }
+
+ total_periods += sample.period;
+ nr_samples++;
+next_event:
+ perf_evlist__mmap_consume(evlist, 0);
+ }
+
+ if ((u64) nr_samples == total_periods) {
+ pr_debug("All (%d) samples have period value of 1!\n",
+ nr_samples);
+ err = -1;
+ }
+
+out_delete_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;
+}