[tip: perf/urgent] selftests/perf_events: Add a SIGTRAP stress test with disables

From: tip-bot2 for Marco Elver
Date: Mon Oct 17 2022 - 10:45:41 EST


The following commit has been merged into the perf/urgent branch of tip:

Commit-ID: 23488ec66867f7e673b694623a951fb583e464a7
Gitweb: https://git.kernel.org/tip/23488ec66867f7e673b694623a951fb583e464a7
Author: Marco Elver <elver@xxxxxxxxxx>
AuthorDate: Tue, 11 Oct 2022 14:45:35 +02:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Mon, 17 Oct 2022 16:32:06 +02:00

selftests/perf_events: Add a SIGTRAP stress test with disables

Add a SIGTRAP stress test that exercises repeatedly enabling/disabling
an event while it concurrently keeps firing.

Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/Y0E3uG7jOywn7vy3@xxxxxxxxxxxxxxxx/
---
tools/testing/selftests/perf_events/sigtrap_threads.c | 35 +++++++++-
1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/perf_events/sigtrap_threads.c b/tools/testing/selftests/perf_events/sigtrap_threads.c
index 6d849dc..d1d8483 100644
--- a/tools/testing/selftests/perf_events/sigtrap_threads.c
+++ b/tools/testing/selftests/perf_events/sigtrap_threads.c
@@ -62,6 +62,8 @@ static struct perf_event_attr make_event_attr(bool enabled, volatile void *addr,
.remove_on_exec = 1, /* Required by sigtrap. */
.sigtrap = 1, /* Request synchronous SIGTRAP on event. */
.sig_data = TEST_SIG_DATA(addr, id),
+ .exclude_kernel = 1, /* To allow */
+ .exclude_hv = 1, /* running as !root */
};
return attr;
}
@@ -93,9 +95,13 @@ static void *test_thread(void *arg)

__atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
iter = ctx.iterate_on; /* read */
- for (i = 0; i < iter - 1; i++) {
- __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
- ctx.iterate_on = iter; /* idempotent write */
+ if (iter >= 0) {
+ for (i = 0; i < iter - 1; i++) {
+ __atomic_fetch_add(&ctx.tids_want_signal, tid, __ATOMIC_RELAXED);
+ ctx.iterate_on = iter; /* idempotent write */
+ }
+ } else {
+ while (ctx.iterate_on);
}

return NULL;
@@ -208,4 +214,27 @@ TEST_F(sigtrap_threads, signal_stress)
EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0));
}

+TEST_F(sigtrap_threads, signal_stress_with_disable)
+{
+ const int target_count = NUM_THREADS * 3000;
+ int i;
+
+ ctx.iterate_on = -1;
+
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ pthread_barrier_wait(&self->barrier);
+ while (__atomic_load_n(&ctx.signal_count, __ATOMIC_RELAXED) < target_count) {
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_DISABLE, 0), 0);
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_ENABLE, 0), 0);
+ }
+ ctx.iterate_on = 0;
+ for (i = 0; i < NUM_THREADS; i++)
+ ASSERT_EQ(pthread_join(self->threads[i], NULL), 0);
+ EXPECT_EQ(ioctl(self->fd, PERF_EVENT_IOC_DISABLE, 0), 0);
+
+ EXPECT_EQ(ctx.first_siginfo.si_addr, &ctx.iterate_on);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_type, PERF_TYPE_BREAKPOINT);
+ EXPECT_EQ(ctx.first_siginfo.si_perf_data, TEST_SIG_DATA(&ctx.iterate_on, 0));
+}
+
TEST_HARNESS_MAIN