Re: [PATCH] perf test: Skip watchpoint tests if no watchpoints available

Christophe Leroy
2022-11-22T19:19:11Z

Le 21/11/2022 à 11:27, Naveen N. Rao a écrit :
> On IBM Power9, perf watchpoint tests fail since no hardware breakpoints
> are available. Detect this by checking the error returned by
> perf_event_open() and skip the tests in that case.
>
> Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
> tools/perf/tests/wp.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/tests/wp.c b/tools/perf/tests/wp.c
> index 56455da30341b4..cc8719609b19ea 100644
> --- a/tools/perf/tests/wp.c
> +++ b/tools/perf/tests/wp.c
> @@ -59,8 +59,10 @@ static int __event(int wp_type, void *wp_addr, unsigned long wp_len)
> get__perf_event_attr(&attr, wp_type, wp_addr, wp_len);
> fd = sys_perf_event_open(&attr, 0, -1, -1,
> perf_event_open_cloexec_flag());
> - if (fd < 0)
> + if (fd < 0) {
> + fd = -errno;
> pr_debug("failed opening event %x\n", attr.bp_type);
> + }

Do you really need that ?

Can't you directly check errno in the caller ?

>
> return fd;
> }
> @@ -77,7 +79,7 @@ static int test__wp_ro(struct test_suite *test __maybe_unused,
>
> fd = __event(HW_BREAKPOINT_R, (void *)&data1, sizeof(data1));
> if (fd < 0)
> - return -1;
> + return fd == -ENODEV ? TEST_SKIP : -1;
>
> tmp = data1;
> WP_TEST_ASSERT_VAL(fd, "RO watchpoint", 1);
> @@ -101,7 +103,7 @@ static int test__wp_wo(struct test_suite *test __maybe_unused,
>
> fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
> if (fd < 0)
> - return -1;
> + return fd == -ENODEV ? TEST_SKIP : -1;
>
> tmp = data1;
> WP_TEST_ASSERT_VAL(fd, "WO watchpoint", 0);
> @@ -126,7 +128,7 @@ static int test__wp_rw(struct test_suite *test __maybe_unused,
> fd = __event(HW_BREAKPOINT_R | HW_BREAKPOINT_W, (void *)&data1,
> sizeof(data1));
> if (fd < 0)
> - return -1;
> + return fd == -ENODEV ? TEST_SKIP : -1;
>
> tmp = data1;
> WP_TEST_ASSERT_VAL(fd, "RW watchpoint", 1);
> @@ -150,7 +152,7 @@ static int test__wp_modify(struct test_suite *test __maybe_unused, int subtest _
>
> fd = __event(HW_BREAKPOINT_W, (void *)&data1, sizeof(data1));
> if (fd < 0)
> - return -1;
> + return fd == -ENODEV ? TEST_SKIP : -1;
>
> data1 = tmp;
> WP_TEST_ASSERT_VAL(fd, "Modify watchpoint", 1);
>
> base-commit: 63a3bf5e8d9e79ce456c8f73d4395a5a51d841b1