[PATCH v12 3/8] perf tests: Add testcase for auxiliary evlist

From: Wang Nan
Date: Thu Jun 30 2016 - 22:28:59 EST


Improve test backward-ring-buffer, trace both enter and exit event of
prctl() syscall, utilize auxiliary evlist to mmap enter and exit event
into separated mmaps.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: Nilay Vaish <nilayvaish@xxxxxxxxx>
Cc: He Kuang <hekuang@xxxxxxxxxx>
---
tools/perf/tests/backward-ring-buffer.c | 90 ++++++++++++++++++++++++++-------
tools/perf/util/evlist.h | 8 +++
2 files changed, 80 insertions(+), 18 deletions(-)

diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
index 0731b0b..0b100b8 100644
--- a/tools/perf/tests/backward-ring-buffer.c
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -26,12 +26,21 @@ static void testcase(void)
static int count_samples(struct perf_evlist *evlist, int *sample_count,
int *comm_count)
{
- int i;
+ int i, dummy;
+
+ if (!comm_count)
+ comm_count = &dummy;
+ if (!sample_count)
+ sample_count = &dummy;

for (i = 0; i < evlist->nr_mmaps; i++) {
union perf_event *event;

- perf_evlist__mmap_read_catchup(evlist, i);
+ /*
+ * Before calling count_samples(), ring buffers in backward
+ * evlist should have catched up with newest record
+ * using perf_evlist__mmap_read_catchup_all().
+ */
while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) {
const u32 type = event->header.type;

@@ -51,34 +60,54 @@ static int count_samples(struct perf_evlist *evlist, int *sample_count,
return TEST_OK;
}

-static int do_test(struct perf_evlist *evlist, int mmap_pages,
- int *sample_count, int *comm_count)
+static int do_test(struct perf_evlist *evlist,
+ struct perf_evlist *aux_evlist,
+ int mmap_pages,
+ int *enter_sample_count,
+ int *exit_sample_count,
+ int *comm_count)
{
int err;
char sbuf[STRERR_BUFSIZE];

- err = perf_evlist__mmap(evlist, mmap_pages, true);
+ err = perf_evlist__mmap(evlist, mmap_pages, false);
if (err < 0) {
pr_debug("perf_evlist__mmap: %s\n",
strerror_r(errno, sbuf, sizeof(sbuf)));
return TEST_FAIL;
}

+ err = perf_evlist__mmap(aux_evlist, mmap_pages, true);
+ if (err < 0) {
+ pr_debug("perf_evlist__mmap for aux_evlist: %s\n",
+ strerror_r(errno, sbuf, sizeof(sbuf)));
+ return TEST_FAIL;
+ }
+
perf_evlist__enable(evlist);
testcase();
perf_evlist__disable(evlist);

- err = count_samples(evlist, sample_count, comm_count);
+ perf_evlist__mmap_read_catchup_all(aux_evlist);
+ err = count_samples(aux_evlist, exit_sample_count, comm_count);
+ if (err)
+ goto errout;
+ err = count_samples(evlist, enter_sample_count, NULL);
+ if (err)
+ goto errout;
+errout:
perf_evlist__munmap(evlist);
+ perf_evlist__munmap(aux_evlist);
return err;
}


int test__backward_ring_buffer(int subtest __maybe_unused)
{
- int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
+ int ret = TEST_SKIP, err;
+ int enter_sample_count = 0, exit_sample_count = 0, comm_count = 0;
char pid[16], sbuf[STRERR_BUFSIZE];
- struct perf_evlist *evlist;
+ struct perf_evlist *evlist, *aux_evlist = NULL;
struct perf_evsel *evsel __maybe_unused;
struct parse_events_error parse_error;
struct record_opts opts = {
@@ -115,13 +144,22 @@ int test__backward_ring_buffer(int subtest __maybe_unused)
goto out_delete_evlist;
}

- perf_evlist__config(evlist, &opts, NULL);
+ /*
+ * Set backward bit, ring buffer should be writing from end. Record
+ * it in aux evlist
+ */
+ perf_evlist__last(evlist)->overwrite = true;
+ perf_evlist__last(evlist)->attr.write_backward = 1;

- /* Set backward bit, ring buffer should be writing from end */
- evlist__for_each_entry(evlist, evsel) {
- evsel->overwrite = true;
- evsel->attr.write_backward = 1;
+ err = parse_events(evlist, "syscalls:sys_exit_prctl", &parse_error);
+ if (err) {
+ pr_debug("Failed to parse tracepoint event, try use root\n");
+ ret = TEST_SKIP;
+ goto out_delete_evlist;
}
+ /* Don't set backward bit for exit event. Record it in main evlist */
+
+ perf_evlist__config(evlist, &opts, NULL);

err = perf_evlist__open(evlist);
if (err < 0) {
@@ -130,24 +168,40 @@ int test__backward_ring_buffer(int subtest __maybe_unused)
goto out_delete_evlist;
}

+ aux_evlist = perf_evlist__new_aux(evlist);
+ if (!aux_evlist) {
+ pr_debug("perf_evlist__new_aux failed\n");
+ goto out_delete_evlist;
+ }
+ aux_evlist->backward = true;
+
ret = TEST_FAIL;
- err = do_test(evlist, opts.mmap_pages, &sample_count,
+ err = do_test(evlist, aux_evlist, opts.mmap_pages,
+ &enter_sample_count, &exit_sample_count,
&comm_count);
if (err != TEST_OK)
goto out_delete_evlist;

- if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
- pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
- sample_count, comm_count);
+ if (enter_sample_count != exit_sample_count) {
+ pr_err("Unexpected counter: enter_sample_count=%d, exit_sample_count=%d\n",
+ enter_sample_count, exit_sample_count);
+ goto out_delete_evlist;
+ }
+
+ if ((exit_sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
+ pr_err("Unexpected counter: exit_sample_count=%d, comm_count=%d\n",
+ exit_sample_count, comm_count);
goto out_delete_evlist;
}

- err = do_test(evlist, 1, &sample_count, &comm_count);
+ err = do_test(evlist, aux_evlist, 1, NULL, NULL, NULL);
if (err != TEST_OK)
goto out_delete_evlist;

ret = TEST_OK;
out_delete_evlist:
+ if (aux_evlist)
+ perf_evlist__delete(aux_evlist);
perf_evlist__delete(evlist);
return ret;
}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 99bcc02..d736cd3 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -149,6 +149,14 @@ union perf_event *perf_evlist__mmap_read_backward(struct perf_evlist *evlist,
int idx);
void perf_evlist__mmap_read_catchup(struct perf_evlist *evlist, int idx);

+static inline void perf_evlist__mmap_read_catchup_all(struct perf_evlist *evlist)
+{
+ int i;
+
+ for (i = 0; i < evlist->nr_mmaps; i++)
+ perf_evlist__mmap_read_catchup(evlist, i);
+}
+
void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx);

int perf_evlist__pause(struct perf_evlist *evlist);
--
1.8.3.4