Hi Reinette, Richard,
On 21/10/2026 15:56, Reinette Chatre wrote:
> Hi Ben,
>
> On 10/20/26 9:18 AM, Ben Horgan wrote:
>> On 12/10/2026 08:47, Richard Cheng wrote:
>
>>> diff --git a/tools/testing/selftests/resctrl/cat_test.c
>>> b/tools/testing/selftests/resctrl/cat_test.c
>>> index 0a417267dd74..f4b02b3eedd7 100644
>>> --- a/tools/testing/selftests/resctrl/cat_test.c
>>> +++ b/tools/testing/selftests/resctrl/cat_test.c
>>> @@ -271,8 +271,13 @@ static bool arch_supports_noncont_cat(const struct
>>> resctrl_test *test)
>>> {
>>> unsigned int vendor_id = get_vendor();
>>>
>>> - /* AMD and Hygon always support non-contiguous CBM. */
>>> - if (vendor_id == ARCH_AMD || vendor_id == ARCH_HYGON)
>>> + /*
>>> + * AMD and Hygon always support non-contiguous CBM. ARM/MPAM defines
>>> + * MPAMCFG_CPBM as a bitmap with no contiguity constraint per ARM
>>> + * DDI 0598.
Nit: DDI 0598 is retired. The new spec version is IHI0099.
>>> + */
>>> + if (vendor_id == ARCH_AMD || vendor_id == ARCH_HYGON ||
>>> + vendor_id == ARCH_ARM)
>>> return true;
>>
>> Would it be better not to just to use the information resctrl advertises?
>> /sys/fs/resctrl/info/L3/sparse_masks
>
> The result of this architecture specific test is used to validate that
> /sys/fs/resctrl/info/L3/sparse_masks provides accurate information.
>
> This test was originally developed on Intel where support for
> sparse masks need to be discovered from the hardware.
Ah ok, thanks for putting me straight. The defined(__aarch64__) check looks to
be the common way of
checking in the selftests. This looks fine to me.
Reviewed-by: Ben Horgan <[email protected]>
Thanks,
Ben
>
>>
>> Is there any reason this test doesn't use that other than being written
>> before its introduction?
> Reinette
