[PATCH perf/core v10 23/23] perf-test: Add a test case for SDT event

From: Masami Hiramatsu
Date: Wed Jun 08 2016 - 05:33:05 EST


Add a basic test case for SDT event support.
This test scans an SDT event in perftools and
check whether the SDT event is correctly stored
into the buildid cache.
---
tools/perf/tests/Build | 1
tools/perf/tests/builtin-test.c | 4 +
tools/perf/tests/sdt.c | 114 +++++++++++++++++++++++++++++++++++++++
tools/perf/tests/tests.h | 1
4 files changed, 120 insertions(+)
create mode 100644 tools/perf/tests/sdt.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index 66a2898..4158422 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -39,6 +39,7 @@ perf-y += stat.o
perf-y += event_update.o
perf-y += event-times.o
perf-y += backward-ring-buffer.o
+perf-y += sdt.o

$(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
$(call rule_mkdir)
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 0e95c20..c0e0ccb 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -212,6 +212,10 @@ static struct test generic_tests[] = {
.func = test__backward_ring_buffer,
},
{
+ .desc = "Test SDT event probing",
+ .func = test__sdt_event,
+ },
+ {
.func = NULL,
},
};
diff --git a/tools/perf/tests/sdt.c b/tools/perf/tests/sdt.c
new file mode 100644
index 0000000..d11065e
--- /dev/null
+++ b/tools/perf/tests/sdt.c
@@ -0,0 +1,114 @@
+#include <stdio.h>
+#include <sys/epoll.h>
+#include <util/util.h>
+#include <util/evlist.h>
+#include <linux/filter.h>
+#include "tests.h"
+#include "debug.h"
+#include "probe-file.h"
+#include "build-id.h"
+
+/* To test SDT event, we need libelf support to scan elf binary */
+#if defined(HAVE_SDT_EVENT) && defined(HAVE_LIBELF_SUPPORT)
+
+#include <sys/sdt.h>
+
+static int target_function(void)
+{
+ DTRACE_PROBE(perf, test_target);
+ return TEST_OK;
+}
+
+/* Copied from builtin-buildid-cache.c */
+static int build_id_cache__add_file(const char *filename)
+{
+ char sbuild_id[SBUILD_ID_SIZE];
+ u8 build_id[BUILD_ID_SIZE];
+ int err;
+
+ err = filename__read_build_id(filename, &build_id, sizeof(build_id));
+ if (err < 0) {
+ pr_debug("Failed to read build id of %s\n", filename);
+ return err;
+ }
+
+ build_id__sprintf(build_id, sizeof(build_id), sbuild_id);
+ err = build_id_cache__add_s(sbuild_id, filename, false, false);
+ if (err < 0)
+ pr_debug("Failed to add build id cache of %s\n", filename);
+ return err;
+}
+
+static char *get_self_path(void)
+{
+ char *buf = calloc(PATH_MAX, sizeof(char));
+ if (buf && readlink("/proc/self/exe", buf, PATH_MAX) < 0) {
+ pr_debug("Failed to get correct path of perf\n");
+ free(buf);
+ return NULL;
+ }
+ return buf;
+}
+
+static int search_cached_probe(const char *target,
+ const char *group, const char *event)
+{
+ struct probe_cache *cache = probe_cache__new(target);
+ int ret = 0;
+
+ if (!cache) {
+ pr_debug("Failed to open probe cache of %s\n", target);
+ return -EINVAL;
+ }
+
+ if (!probe_cache__find_by_name(cache, group, event)) {
+ pr_debug("Failed to find %s:%s in the cache\n", group, event);
+ ret = -ENOENT;
+ }
+ probe_cache__delete(cache);
+
+ return ret;
+}
+
+int test__sdt_event(int subtests __maybe_unused)
+{
+ int ret = TEST_FAIL;
+ char __tempdir[] = "./test-buildid-XXXXXX";
+ char *tempdir = NULL, *myself = get_self_path();
+
+ if (myself == NULL || mkdtemp(__tempdir) == NULL) {
+ pr_debug("Failed to make a tempdir for build-id cache\n");
+ goto error;
+ }
+ /* Note that buildid_dir must be an absolute path */
+ tempdir = realpath(__tempdir, NULL);
+
+ /* At first, scan itself */
+ set_buildid_dir(tempdir);
+ if (build_id_cache__add_file(myself) < 0)
+ goto error_rmdir;
+
+ /* Open a cache and make sure the SDT is stored */
+ if (search_cached_probe(myself, "sdt_perf", "test_target") < 0)
+ goto error_rmdir;
+
+ /* TBD: probing on the SDT event and collect logs */
+
+ /* Call the target and get an event */
+ ret = target_function();
+
+error_rmdir:
+ /* Cleanup temporary buildid dir */
+ rm_rf(tempdir);
+error:
+ free(tempdir);
+ free(myself);
+ return ret;
+}
+#else
+int test__sdt_event(int subtests __maybe_unused)
+{
+ pr_debug("Skip SDT event test because SDT support is not compiled\n");
+ return TEST_SKIP;
+}
+#endif
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index c57e72c..93cfb0b 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -87,6 +87,7 @@ int test__synthesize_stat_round(int subtest);
int test__event_update(int subtest);
int test__event_times(int subtest);
int test__backward_ring_buffer(int subtest);
+int test__sdt_event(int subtest);

#if defined(__arm__) || defined(__aarch64__)
#ifdef HAVE_DWARF_UNWIND_SUPPORT