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

[kajoljain <kjain@linux.ibm.com>]

On 11/21/22 15:57, Naveen N. Rao wrote:
> 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>
> ---

Patch looks fine to me. Also tested it in power9 box

Test result without this patch changes :
 23: Watchpoint  :
 23.1: Read Only Watchpoint    : FAILED!
 23.2: Write Only Watchpoint   : FAILED!
 23.3: Read / Write Watchpoint : FAILED!
 23.4: Modify Watchpoint       : FAILED!


Test result with patch changes:
 23: Watchpoint  :
 23.1: Read Only Watchpoint    : Skip (missing hardware support)
 23.2: Write Only Watchpoint   : Skip (missing hardware support)
 23.3: Read / Write Watchpoint : Skip (missing hardware support)
 23.4: Modify Watchpoint       : Skip (missing hardware support)


Reviewed-by: Kajol Jain<kjain@linux.ibm.com>
Tested-by: Kajol Jain<kjain@linux.ibm.com>

Thanks,
Kajol Jain

>  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);
> +	}
>  
>  	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