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.
>> + */
>> + 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.
>
> Is there any reason this test doesn't use that other than being written
> before its introduction?
Reinette
