On Fri, 21 Apr 2023, Reinette Chatre wrote:
> 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.
Ah, indeed, it's checked on the higher level so this fix is unnecessary.
I missed it entirely while taking this change out from a more complex
change and even failed to make the connection when I stared at the very if
<= 0 check not so many days ago.
--
i.
> > 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);
