Hi Maciej, On 10/5/2023 1:14 AM, Maciej Wieczor-Retman wrote: > Until recently Intel CPUs didn't support using non-contiguous 1s > in Cache Allocation Technology (CAT). Writing a bitmask with > non-contiguous 1s to the resctrl schemata file would fail. > > Intel CPUs that support non-contiguous 1s can be identified through a > CPUID leaf mentioned in the "Intel® 64 and IA-32 Architectures > Software Developer’s Manual" document available at: > https://www.intel.com/content/www/us/en/developer/articles/technical/intel-sdm.html > > Add kernel support for detecting if non-contiguous 1s in Cache > Allocation Technology (CAT) are supported by the hardware. Also add a > new resctrl FS file to output this information to the userspace. > Keep the hardcoded value for Haswell CPUs only since they do not have > CPUID enumeration support for Cache allocation. > > Since the selftests/resctrl files are going through many rewrites and > cleanups the appropriate selftest is still a work in progress. For > basic selftesting capabilities use the bash script attached below this > paragraph. It checks whether various bitmasks written into resctrl FS > generate output consistent with reported feature support. This work conflicts with Babu's series [1] that is also ready for inclusion. We could wait for outcome of next level review to determine who will need to rebase. It may help to provide a snippet of the conflict resolution in anticipation of Babu's series being merged first (I will propose exactly the same to Babu for the scenario of this work merged first). Reinette [1] https://lore.kernel.org/lkml/20231003235430.1231238-1-babu.moger@xxxxxxx/
