[PATCH 06/10] libperf: Add tests_mmap_thread test

From: Jiri Olsa
Date: Thu Oct 17 2019 - 07:00:06 EST


Adding mmaping tests that generates 100 prctl calls
in monitored child process and validates it gets
100 events in ring buffer.

Link: http://lkml.kernel.org/n/tip-5qzuxnmde9x6uojkysp3rldn@xxxxxxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/lib/tests/test-evlist.c | 119 +++++++++++++++++++++++++++++
1 file changed, 119 insertions(+)

diff --git a/tools/perf/lib/tests/test-evlist.c b/tools/perf/lib/tests/test-evlist.c
index e6b2ab2e2bde..90a1869ba4b1 100644
--- a/tools/perf/lib/tests/test-evlist.c
+++ b/tools/perf/lib/tests/test-evlist.c
@@ -1,12 +1,21 @@
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdarg.h>
+#include <unistd.h>
+#include <stdlib.h>
#include <linux/perf_event.h>
+#include <linux/limits.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/prctl.h>
#include <perf/cpumap.h>
#include <perf/threadmap.h>
#include <perf/evlist.h>
#include <perf/evsel.h>
+#include <perf/mmap.h>
+#include <perf/event.h>
#include <internal/tests.h>
+#include <api/fs/fs.h>

static int libperf_print(enum libperf_print_level level,
const char *fmt, va_list ap)
@@ -181,6 +190,115 @@ static int test_stat_thread_enable(void)
return 0;
}

+static int test_mmap_thread(void)
+{
+ struct perf_evlist *evlist;
+ struct perf_evsel *evsel;
+ struct perf_mmap *map;
+ struct perf_cpu_map *cpus;
+ struct perf_thread_map *threads;
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_TRACEPOINT,
+ .sample_period = 1,
+ .wakeup_watermark = 1,
+ .disabled = 1,
+ };
+ char path[PATH_MAX];
+ int id, err, pid, go_pipe[2];
+ union perf_event *event;
+ char bf;
+ int count = 0;
+
+ snprintf(path, PATH_MAX, "%s/kernel/debug/tracing/events/syscalls/sys_enter_prctl/id",
+ sysfs__mountpoint());
+
+ if (filename__read_int(path, &id)) {
+ fprintf(stderr, "error: failed to get tracepoint id: %s\n", path);
+ return -1;
+ }
+
+ attr.config = id;
+
+ err = pipe(go_pipe);
+ __T("failed to create pipe", err == 0);
+
+ fflush(NULL);
+
+ pid = fork();
+ if (!pid) {
+ int i;
+
+ read(go_pipe[0], &bf, 1);
+
+ /* Generate 100 prctl calls. */
+ for (i = 0; i < 100; i++)
+ prctl(0, 0, 0, 0, 0);
+
+ exit(0);
+ }
+
+ threads = perf_thread_map__new_dummy();
+ __T("failed to create threads", threads);
+
+ cpus = perf_cpu_map__dummy_new();
+ __T("failed to create cpus", cpus);
+
+ perf_thread_map__set_pid(threads, 0, pid);
+
+ evlist = perf_evlist__new();
+ __T("failed to create evlist", evlist);
+
+ evsel = perf_evsel__new(&attr);
+ __T("failed to create evsel1", evsel);
+
+ perf_evlist__add(evlist, evsel);
+
+ perf_evlist__set_maps(evlist, cpus, threads);
+
+ err = perf_evlist__open(evlist);
+ __T("failed to open evlist", err == 0);
+
+ err = perf_evlist__mmap(evlist, 4);
+ __T("failed to mmap evlist", err == 0);
+
+ perf_evlist__enable(evlist);
+
+ /* kick the child and wait for it to finish */
+ write(go_pipe[1], &bf, 1);
+ waitpid(pid, NULL, 0);
+
+ /*
+ * There's no need to call perf_evlist__disable,
+ * monitored process is dead now.
+ */
+
+ perf_evlist__for_each_mmap(evlist, map, false) {
+ if (perf_mmap__read_init(map) < 0)
+ continue;
+
+ while ((event = perf_mmap__read_event(map)) != NULL) {
+ count++;
+ perf_mmap__consume(map);
+ }
+
+ perf_mmap__read_done(map);
+ }
+
+ /* calls perf_evlist__munmap/perf_evlist__close */
+ perf_evlist__delete(evlist);
+
+ perf_thread_map__put(threads);
+ perf_cpu_map__put(cpus);
+
+ /*
+ * The generated prctl calls should match the
+ * number of events in the buffer.
+ */
+ __T("failed count", count == 100);
+
+ return 0;
+}
+
int main(int argc, char **argv)
{
__T_START;
@@ -190,6 +308,7 @@ int main(int argc, char **argv)
test_stat_cpu();
test_stat_thread();
test_stat_thread_enable();
+ test_mmap_thread();

__T_OK;
return 0;
--
2.21.0