Re: [PATCH] perf: Generate EXIT event only once per task context

Namhyung Kim
2013-03-15T08:59:39Z

Hi,

I added a test case for this. Please take a look on it too.
This patch is based on my previous evlist cleanup patchset:

https://lkml.org/lkml/2013/3/15/47

Thanks,
Namhyung

>From df86ff1984a2ab89331a10f5e1fc93f09e260ed9 Mon Sep 17 00:00:00 2001
From: Namhyung Kim <namhyung.kim@lge.com>
Date: Fri, 15 Mar 2013 14:58:11 +0900
Subject: [PATCH] perf test: Add test case for checking number of EXIT events

The test__task_exit() runs a simple "/usr/bin/true" workload and then
checks whether the number of EXIT event is 1 or not.

Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/Makefile | 1 +
tools/perf/tests/builtin-test.c | 4 ++
tools/perf/tests/task-exit.c | 123 ++++++++++++++++++++++++++++++++++++++++
tools/perf/tests/tests.h | 1 +
4 files changed, 129 insertions(+)
create mode 100644 tools/perf/tests/task-exit.c

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index 3dcd6273a90b..0145df853af4 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -511,6 +511,7 @@ LIB_OBJS += $(OUTPUT)tests/evsel-tp-sched.o
LIB_OBJS += $(OUTPUT)tests/pmu.o
LIB_OBJS += $(OUTPUT)tests/hists_link.o
LIB_OBJS += $(OUTPUT)tests/python-use.o
+LIB_OBJS += $(OUTPUT)tests/task-exit.o

BUILTIN_OBJS += $(OUTPUT)builtin-annotate.o
BUILTIN_OBJS += $(OUTPUT)builtin-bench.o
diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index acb98e0e39f2..dd00e5e444f8 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -78,6 +78,10 @@ static struct test {
.func = test__python_use,
},
{
+ .desc = "Test number of exit event of a simple workload",
+ .func = test__task_exit,
+ },
+ {
.func = NULL,
},
};
diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c
new file mode 100644
index 000000000000..28fe5894b061
--- /dev/null
+++ b/tools/perf/tests/task-exit.c
@@ -0,0 +1,123 @@
+#include "evlist.h"
+#include "evsel.h"
+#include "thread_map.h"
+#include "cpumap.h"
+#include "tests.h"
+
+#include <signal.h>
+
+static int exited;
+static int nr_exit;
+
+static void sig_handler(int sig)
+{
+ exited = 1;
+
+ if (sig == SIGUSR1)
+ nr_exit = -1;
+}
+
+/*
+ * This test will start a workload that does nothing then it checks
+ * if the number of exit event reported by the kernel is 1 or not
+ * in order to check the kernel returns correct number of event.
+ */
+int test__task_exit(void)
+{
+ int err = -1;
+ union perf_event *event;
+ struct perf_evsel *evsel;
+ struct perf_evlist *evlist;
+ struct perf_target target = {
+ .uid = UINT_MAX,
+ .uses_mmap = true,
+ };
+ const char *argv[] = { "true", NULL };
+
+ signal(SIGCHLD, sig_handler);
+ signal(SIGUSR1, sig_handler);
+
+ evlist = perf_evlist__new();
+ if (evlist == NULL) {
+ pr_debug("perf_evlist__new\n");
+ return -1;
+ }
+ /*
+ * We need at least one evsel in the evlist, use the default
+ * one: "cycles".
+ */
+ err = perf_evlist__add_default(evlist);
+ if (err < 0) {
+ pr_debug("Not enough memory to create evsel\n");
+ goto out_free_evlist;
+ }
+
+ /*
+ * Create maps of threads and cpus to monitor. In this case
+ * we start with all threads and cpus (-1, -1) but then in
+ * perf_evlist__prepare_workload we'll fill in the only thread
+ * we're monitoring, the one forked there.
+ */
+ evlist->cpus = cpu_map__dummy_new();
+ evlist->threads = thread_map__new_by_tid(-1);
+ if (!evlist->cpus || !evlist->threads) {
+ err = -ENOMEM;
+ pr_debug("Not enough memory to create thread/cpu maps\n");
+ goto out_delete_maps;
+ }
+
+ err = perf_evlist__prepare_workload(evlist, &target, argv, false, true);
+ if (err < 0) {
+ pr_debug("Couldn't run the workload!\n");
+ goto out_delete_maps;
+ }
+
+ evsel = perf_evlist__first(evlist);
+ evsel->attr.task = 1;
+ evsel->attr.sample_freq = 0;
+ evsel->attr.inherit = 0;
+ evsel->attr.watermark = 0;
+ evsel->attr.wakeup_events = 1;
+ evsel->attr.exclude_kernel = 1;
+
+ err = perf_evlist__open(evlist);
+ if (err < 0) {
+ pr_debug("Couldn't open the evlist: %s\n", strerror(-err));
+ goto out_delete_maps;
+ }
+
+ if (perf_evlist__mmap(evlist, 128, true) < 0) {
+ pr_debug("failed to mmap events: %d (%s)\n", errno,
+ strerror(errno));
+ goto out_close_evlist;
+ }
+
+ perf_evlist__start_workload(evlist);
+
+retry:
+ while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
+ if (event->header.type != PERF_RECORD_EXIT)
+ continue;
+
+ nr_exit++;
+ }
+
+ if (!exited || !nr_exit) {
+ poll(evlist->pollfd, evlist->nr_fds, -1);
+ goto retry;
+ }
+
+ if (nr_exit != 1) {
+ pr_debug("received %d EXIT records\n", nr_exit);
+ err = -1;
+ }
+
+ perf_evlist__munmap(evlist);
+out_close_evlist:
+ perf_evlist__close(evlist);
+out_delete_maps:
+ perf_evlist__delete_maps(evlist);
+out_free_evlist:
+ perf_evlist__delete(evlist);
+ return err;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 5de0be1ff4b6..4590c10b7e65 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -23,5 +23,6 @@ int test__dso_data(void);
int test__parse_events(void);
int test__hists_link(void);
int test__python_use(void);
+int test__task_exit(void);

#endif /* TESTS_H */
--
1.8.1.4