[PATCH 0/2] x86/numa_emulation: Introduce uniform split capability

From: Dan Williams
Date: Sat May 26 2018 - 21:06:50 EST


The current numa emulation capabilities for splitting System RAM by a
fixed size or by a set number of nodes may result in some nodes being
larger than others. The implementation prioritizes establishing a
minimum usable memory size over satisfying the requested number of numa
nodes.

Introduce a uniform split capability that evenly partitions each
physical numa node into N emulated nodes. For example numa=fake=3U
creates 6 emulated nodes total on a system that has 2 physical nodes.

This capability is useful for debugging and evaluating platform
memory-side-cache capabilities as described by the ACPI HMAT (see
5.2.27.5 Memory Side Cache Information Structure in ACPI 6.2a)

See more details in patch2.

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Dan Williams (2):
x86/numa_emulation: Fix emulated-to-physical node mapping
x86/numa_emulation: Introduce uniform split capability


Documentation/x86/x86_64/boot-options.txt | 4 +
arch/x86/mm/numa_emulation.c | 98 +++++++++++++++++++++++------
2 files changed, 82 insertions(+), 20 deletions(-)