[PATCH v2 0/2] x86/resctrl: Workaround MBM errata

From: Fenghua Yu
Date: Mon Oct 12 2020 - 22:47:13 EST


Intel Memory Bandwidth Monitoring (MBM) counters may report system
memory bandwidth incorrectly on some Intel processors. The errata are
reported in erratum SKX99 [1], erratum BDF102 [2] and RDT reference
manual [3].

The errata are worked around using a correction factor table. Since
the correction factor table is not publicly documented anywhere, it's
documented in Documentation/x86/resctrl.rst along with the errata.

1. Erratum SKX99 in Intel Xeon Processor Scalable Family Specification
Update:
http://web.archive.org/web/20200716124958/https://www.intel.com/content/www/us/en/processors/xeon/scalable/xeon-scalable-spec-update.html
2. Erratum BDF102 in Intel Xeon E5-2600 v4 Processor Product Family
Specification Update:
http://web.archive.org/web/20191125200531/https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-v4-spec-update.pdf
3. The errata in Intel Resource Director Technology (Intel RDT) on 2nd
Generation Intel Xeon Scalable Processors Reference Manual:
https://software.intel.com/content/www/us/en/develop/articles/intel-resource-director-technology-rdt-reference-manual.html

Change Log:
v2:
- Document the errata and the correction table in resctrl.rst (Boris).
- Address various comments on patch 2 (Boris).
- Change the documentation URLs to stable archive.org (Tony).

Fenghua Yu (2):
Documentation: x86: Rename resctrl_ui.rst and add two errata to the
file
x86/resctrl: Correct MBM total and local values

Documentation/conf.py | 2 +-
Documentation/x86/index.rst | 2 +-
.../x86/{resctrl_ui.rst => resctrl.rst} | 82 ++++++++++++++++++
arch/x86/kernel/cpu/resctrl/core.c | 4 +
arch/x86/kernel/cpu/resctrl/internal.h | 1 +
arch/x86/kernel/cpu/resctrl/monitor.c | 83 ++++++++++++++++++-
6 files changed, 170 insertions(+), 4 deletions(-)
rename Documentation/x86/{resctrl_ui.rst => resctrl.rst} (92%)

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