Hi Ilpo,
On 4/18/2023 4:44 AM, Ilpo Järvinen wrote:
> CAT test only validates that the number of CBM bits is not too large
> but it could be too small too.
Could you please elaborate how this scenario could occur?
> Check and return error before starting the CAT test if the number of
> CBM bits is too small.
>
> Fixes: 09a67934625a ("selftests/resctrl: Don't hard code value of "no_of_bits" variable")
This fix is not clear to me. This commit being fixed already contains
an explicit test that will bail out of no_of_bits <= 0. It is not clear to me
why it is necessary to adding a test for < 1 as a fix for this commit.
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> ---
> tools/testing/selftests/resctrl/cat_test.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
> index fb1443f888c4..722c9cd4120d 100644
> --- a/tools/testing/selftests/resctrl/cat_test.c
> +++ b/tools/testing/selftests/resctrl/cat_test.c
> @@ -129,7 +129,7 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
> if (!n)
> n = count_of_bits / 2;
>
> - if (n > count_of_bits - 1) {
> + if (n < 1 || n > count_of_bits - 1) {
> ksft_print_msg("Invalid input value for no_of_bits n!\n");
> ksft_print_msg("Please enter value in range 1 to %d\n",
> count_of_bits - 1);
Reinette
