Re: [PATCH 3/3] selftests/resctrl: Fix non-contiguous CBM check for Hygon

From: Reinette Chatre

Date: Thu Dec 04 2025 - 19:55:35 EST


Hi Xiaochen,

On 12/4/25 4:38 AM, Xiaochen Shen wrote:
> The resctrl selftest currently fails on Hygon CPUs that always supports
> non-contiguous CBM, printing the error:
>
> "# Hardware and kernel differ on non-contiguous CBM support!"
>
> This occurs because the arch_supports_noncont_cat() function lacks
> vendor detection for Hygon CPUs, preventing proper identification of
> their non-contiguous CBM capability.
>
> Fix this by adding Hygon vendor ID detection to
> arch_supports_noncont_cat().
>
> Signed-off-by: Xiaochen Shen <shenxiaochen@xxxxxxxxxxxxxx>
> ---

I think it may help to add a maintainer note here to highlight even though this
is a fix it is not a candidate for backport since, based on your other series,
support for Hygon is in process of being added to resctrl.

> tools/testing/selftests/resctrl/cat_test.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
> index 94cfdba5308d..59a0f80fdc5a 100644
> --- a/tools/testing/selftests/resctrl/cat_test.c
> +++ b/tools/testing/selftests/resctrl/cat_test.c
> @@ -290,8 +290,8 @@ static int cat_run_test(const struct resctrl_test *test, const struct user_param
>
> static bool arch_supports_noncont_cat(const struct resctrl_test *test)
> {
> - /* AMD always supports non-contiguous CBM. */
> - if (get_vendor() == ARCH_AMD)
> + /* AMD and Hygon always supports non-contiguous CBM. */
> + if (get_vendor() == ARCH_AMD || get_vendor() == ARCH_HYGON)
> return true;
>
> #if defined(__i386__) || defined(__x86_64__) /* arch */

Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>

Reinette