[PATCH 0/4] Add interfaces for ACPI MRRM table

From: Tony Luck
Date: Mon Feb 10 2025 - 16:12:39 EST


Memory used to be homogeneous. Then NUMA came along. Later different
types of memory (persistent memory, on-package high bandwidth memory,
CXL attached memory).

Each type of memory has its own performance characteristics, and users
will need to monitor and control access by type.

The MRRM solution is to tag physical address ranges with "region IDs"
so that platform firmware[1] can indicate the type of memory for each
range (with separate tags available for local vs. remote access to
each range).

The region IDs will be used to provide separate event counts for each
region for "perf" and for the "resctrl" file system to monitor and
control memory bandwidth in each region.

Users will need to know the address range(s) that are part of each
region. This patch series adds /sys/devices/memory/rangeX directories
to provide user space accessible enumeration.

-Tony

[1] MRRM definition allow for future expansion for the OS to assign
these region IDs.

Fenghua Yu (1):
ACPICA: Define MRRM ACPI table

Tony Luck (3):
ACPI/MRRM: Create /sys/devices/system/memory/rangeX ABI
ACPI/MRRM: Add "node" symlink to /sys/devices/system/memory/rangeX
ACPI/MRRM: ABI documentation for /sys/devices/system/memory/rangeX

include/linux/memory.h | 9 +
include/acpi/actbl3.h | 40 ++++
drivers/acpi/acpi_mrrm.c | 188 ++++++++++++++++++
drivers/base/memory.c | 9 +
.../ABI/testing/sysfs-devices-memory | 32 +++
arch/x86/Kconfig | 1 +
drivers/acpi/Kconfig | 4 +
drivers/acpi/Makefile | 1 +
8 files changed, 284 insertions(+)
create mode 100644 drivers/acpi/acpi_mrrm.c


base-commit: a64dcfb451e254085a7daee5fe51bf22959d52d3
--
2.48.1