From c5b81449f915a28bb9c7725e53aebab3ba39b4a2 Mon Sep 17 00:00:00 2001 From: Marco Elver Date: Mon, 29 Aug 2022 14:47:07 +0200 Subject: perf/hw_breakpoint: Provide hw_breakpoint_is_used() and use in test Provide hw_breakpoint_is_used() to check if breakpoints are in use on the system. Use it in the KUnit test to verify the global state before and after a test case. Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Dmitry Vyukov Acked-by: Ian Rogers Link: https://lore.kernel.org/r/20220829124719.675715-3-elver@google.com --- kernel/events/hw_breakpoint_test.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel/events/hw_breakpoint_test.c') diff --git a/kernel/events/hw_breakpoint_test.c b/kernel/events/hw_breakpoint_test.c index 433c5c45e2a5..5ced822df788 100644 --- a/kernel/events/hw_breakpoint_test.c +++ b/kernel/events/hw_breakpoint_test.c @@ -294,7 +294,14 @@ static struct kunit_case hw_breakpoint_test_cases[] = { static int test_init(struct kunit *test) { /* Most test cases want 2 distinct CPUs. */ - return num_online_cpus() < 2 ? -EINVAL : 0; + if (num_online_cpus() < 2) + return -EINVAL; + + /* Want the system to not use breakpoints elsewhere. */ + if (hw_breakpoint_is_used()) + return -EBUSY; + + return 0; } static void test_exit(struct kunit *test) @@ -308,6 +315,9 @@ static void test_exit(struct kunit *test) kthread_stop(__other_task); __other_task = NULL; } + + /* Verify that internal state agrees that no breakpoints are in use. */ + KUNIT_EXPECT_FALSE(test, hw_breakpoint_is_used()); } static struct kunit_suite hw_breakpoint_test_suite = { -- cgit v1.2.3