[PATCH v15 3/8] perf tests: Add testcase for auxiliary evlist

From: Wang Nan
Date: Mon Jul 11 2016 - 02:55:16 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 | 103 ++++++++++++++++++++++++++------
1 file changed, 84 insertions(+), 19 deletions(-)

diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
index 1750ef2..2e66c48 100644
--- a/tools/perf/tests/backward-ring-buffer.c
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -23,16 +23,34 @@ static void testcase(void)
}
}

+static 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);
+}
+
static int count_samples(struct perf_evlist *evlist, int *sample_count,
int *comm_count)
{
int i;
+ union perf_event *(*reader)(struct perf_evlist *, int);
+
+ if (evlist->backward)
+ reader = perf_evlist__mmap_read_backward;
+ else
+ reader = perf_evlist__mmap_read_forward;

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

- perf_evlist__mmap_read_catchup(evlist, i);
- while ((event = perf_evlist__mmap_read_backward(evlist, i)) != NULL) {
+ /*
+ * 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 = (*reader)(evlist, i)) != NULL) {
const u32 type = event->header.type;

switch (type) {
@@ -51,34 +69,57 @@ 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)
+struct test_result {
+ int sys_enter;
+ int sys_exit;
+ int comm;
+};
+
+static int do_test(struct perf_evlist *evlist,
+ struct perf_evlist *aux_evlist,
+ int mmap_pages,
+ struct test_result *res)
{
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, &res->sys_exit, &res->comm);
+ if (err)
+ goto errout;
+ err = count_samples(evlist, &res->sys_enter, &res->comm);
+ 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;
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 = {
@@ -90,6 +131,7 @@ int test__backward_ring_buffer(int subtest __maybe_unused)
.mmap_pages = 256,
.default_interval = 1,
};
+ struct test_result res = {0, 0, 0};

snprintf(pid, sizeof(pid), "%d", getpid());
pid[sizeof(pid) - 1] = '\0';
@@ -101,7 +143,6 @@ int test__backward_ring_buffer(int subtest __maybe_unused)
return TEST_FAIL;
}

- evlist->backward = true;
err = perf_evlist__create_maps(evlist, &opts.target);
if (err < 0) {
pr_debug("Not enough memory to create thread/cpu maps\n");
@@ -116,11 +157,21 @@ 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)->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 */

- /* Set backward bit, ring buffer should be writing from end */
- evlist__for_each_entry(evlist, evsel)
- evsel->attr.write_backward = 1;
+ perf_evlist__config(evlist, &opts, NULL);

err = perf_evlist__open(evlist);
if (err < 0) {
@@ -129,24 +180,38 @@ 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,
- &comm_count);
+ err = do_test(evlist, aux_evlist, opts.mmap_pages, &res);
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 (res.sys_enter != res.sys_exit) {
+ pr_err("Unexpected counter: sys_enter count=%d, sys_exit count=%d\n",
+ res.sys_enter, res.sys_exit);
+ goto out_delete_evlist;
+ }
+
+ if ((res.sys_exit != NR_ITERS) || (res.comm != NR_ITERS)) {
+ pr_err("Unexpected counter: sys_exit count=%d, comm count=%d\n",
+ res.sys_exit, res.comm);
goto out_delete_evlist;
}

- err = do_test(evlist, 1, &sample_count, &comm_count);
+ err = do_test(evlist, aux_evlist, 1, &res);
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;
}
--
1.8.3.4