selftests/bpf: Bump internal send_signal/send_signal_tracepoint timeout
authorDaniel Müller <deso@posteo.net>
Wed, 27 Jul 2022 18:29:55 +0000 (18:29 +0000)
committerAndrii Nakryiko <andrii@kernel.org>
Fri, 29 Jul 2022 18:10:01 +0000 (11:10 -0700)
The send_signal/send_signal_tracepoint is pretty flaky, with at least
one failure in every ten runs on a few attempts I've tried it:
  > test_send_signal_common:PASS:pipe_c2p 0 nsec
  > test_send_signal_common:PASS:pipe_p2c 0 nsec
  > test_send_signal_common:PASS:fork 0 nsec
  > test_send_signal_common:PASS:skel_open_and_load 0 nsec
  > test_send_signal_common:PASS:skel_attach 0 nsec
  > test_send_signal_common:PASS:pipe_read 0 nsec
  > test_send_signal_common:PASS:pipe_write 0 nsec
  > test_send_signal_common:PASS:reading pipe 0 nsec
  > test_send_signal_common:PASS:reading pipe error: size 0 0 nsec
  > test_send_signal_common:FAIL:incorrect result unexpected incorrect result: actual 48 != expected 50
  > test_send_signal_common:PASS:pipe_write 0 nsec
  > #139/1   send_signal/send_signal_tracepoint:FAIL

The reason does not appear to be a correctness issue in the strict
sense. Rather, we merely do not receive the signal we are waiting for
within the provided timeout.
Let's bump the timeout by a factor of ten. With that change I have not
been able to reproduce the failure in 150+ iterations. I am also sneaking
in a small simplification to the test_progs test selection logic.

Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220727182955.4044988-1-deso@posteo.net
tools/testing/selftests/bpf/prog_tests/send_signal.c
tools/testing/selftests/bpf/test_progs.c

index d71226e..d63a20f 100644 (file)
@@ -64,7 +64,7 @@ static void test_send_signal_common(struct perf_event_attr *attr,
                ASSERT_EQ(read(pipe_p2c[0], buf, 1), 1, "pipe_read");
 
                /* wait a little for signal handler */
-               for (int i = 0; i < 100000000 && !sigusr1_received; i++)
+               for (int i = 0; i < 1000000000 && !sigusr1_received; i++)
                        j /= i + j + 1;
 
                buf[0] = sigusr1_received ? '2' : '0';
index c639f2e..3561c97 100644 (file)
@@ -1604,11 +1604,8 @@ int main(int argc, char **argv)
                struct prog_test_def *test = &prog_test_defs[i];
 
                test->test_num = i + 1;
-               if (should_run(&env.test_selector,
-                               test->test_num, test->test_name))
-                       test->should_run = true;
-               else
-                       test->should_run = false;
+               test->should_run = should_run(&env.test_selector,
+                                             test->test_num, test->test_name);
 
                if ((test->run_test == NULL && test->run_serial_test == NULL) ||
                    (test->run_test != NULL && test->run_serial_test != NULL)) {