[PATCH v2 0/2] selftests/resctrl: SNC kernel support discovery

[Maciej Wieczor-Retman]

Changes v2:
- Removed patches 2 and 3 since now this part will be supported by the
  kernel.

Sub-Numa Clustering (SNC) allows splitting CPU cores, caches and memory
into multiple NUMA nodes. When enabled, NUMA-aware applications can
achieve better performance on bigger server platforms.

SNC support in the kernel is currently in review [1]. With SNC enabled
and kernel support in place all the tests will function normally. There
might be a problem when SNC is enabled but the system is still using an
older kernel version without SNC support. Currently the only message
displayed in that situation is a guess that SNC might be enabled and is
causing issues. That message also is displayed whenever the test fails
on an Intel platform.

Add a mechanism to discover kernel support for SNC which will add more
meaning and certainty to the error message.

Series was tested on Ice Lake server platforms with SNC disabled, SNC-2
and SNC-4. The tests were also ran with and without kernel support for
SNC.

Series applies cleanly on kselftest/next.

[1] https://lore.kernel.org/all/20240503203325.21512-1-tony.luck@xxxxxxxxx/

Previous versions of this series:
[v1] https://lore.kernel.org/all/cover.1709721159.git.maciej.wieczor-retman@xxxxxxxxx/

Maciej Wieczor-Retman (2):
  selftests/resctrl: Adjust effective L3 cache size with SNC enabled
  selftests/resctrl: Adjust SNC support messages

 tools/testing/selftests/resctrl/cat_test.c  |   2 +-
 tools/testing/selftests/resctrl/cmt_test.c  |   6 +-
 tools/testing/selftests/resctrl/mba_test.c  |   2 +
 tools/testing/selftests/resctrl/mbm_test.c  |   4 +-
 tools/testing/selftests/resctrl/resctrl.h   |   8 +-
 tools/testing/selftests/resctrl/resctrlfs.c | 131 +++++++++++++++++++-
 6 files changed, 144 insertions(+), 9 deletions(-)

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2.45.0