Re: [PATCHv5 00/10] Heterogeneuos memory node attributes

Michal Hocko
2019-01-28T14:00:09Z

Is there any reason why is this not CCing linux-api (Cced now).

On Thu 24-01-19 16:07:14, Keith Busch wrote:
> == Changes since v4 ==
>
> All public interfaces have kernel docs.
>
> Renamed "class" to "access", docs and changed logs updated
> accordingly. (Rafael)
>
> The sysfs hierarchy is altered to put initiators and targets in their
> own attribute group directories (Rafael).
>
> The node lists are removed. This feedback is in conflict with v1
> feedback, but consensus wants to remove multi-value sysfs attributes,
> which includes lists. We only have symlinks now, just like v1 provided.
>
> Documentation and code patches are combined such that the code
> introducing new attributes and its documentation are in the same
> patch. (Rafael and Dan).
>
> The performance attributes, bandwidth and latency, are moved into the
> initiators directory. This should make it obvious for which node
> access the attributes apply, which was previously ambiguous.
> (Jonathan Cameron).
>
> The HMAT code selecting "local" initiators is substantially changed.
> Only PXM's that have identical performance to the HMAT's processor PXM
> in Address Range Structure are registered. This is to avoid considering
> nodes identical when only one of several perf attributes are the same.
> (Jonathan Cameron).
>
> Verbose variable naming. Examples include "initiator" and "target"
> instead of "i" and "t", "mem_pxm" and "cpu_pxm" instead of "m" and
> "p". (Rafael)
>
> Compile fixes for when HMEM_REPORTING is not set. This is not a user
> selectable config option, default 'n', and will have to be selected
> by other config options that require it (Greg KH and Rafael).
>
> == Background ==
>
> Platforms may provide multiple types of cpu attached system memory. The
> memory ranges for each type may have different characteristics that
> applications may wish to know about when considering what node they want
> their memory allocated from.
>
> It had previously been difficult to describe these setups as memory
> rangers were generally lumped into the NUMA node of the CPUs. New
> platform attributes have been created and in use today that describe
> the more complex memory hierarchies that can be created.
>
> This series' objective is to provide the attributes from such systems
> that are useful for applications to know about, and readily usable with
> existing tools and libraries.

Can you provide a highlevel description of these new attributes and how
they are supposed to be used.

Mentioning usecases is also due consideirng the amount of code this
adds.

> Keith Busch (10):
> acpi: Create subtable parsing infrastructure
> acpi: Add HMAT to generic parsing tables
> acpi/hmat: Parse and report heterogeneous memory
> node: Link memory nodes to their compute nodes
> acpi/hmat: Register processor domain to its memory
> node: Add heterogenous memory access attributes
> acpi/hmat: Register performance attributes
> node: Add memory caching attributes
> acpi/hmat: Register memory side cache attributes
> doc/mm: New documentation for memory performance
>
> Documentation/ABI/stable/sysfs-devices-node | 87 ++++-
> Documentation/admin-guide/mm/numaperf.rst | 167 ++++++++
> arch/arm64/kernel/acpi_numa.c | 2 +-
> arch/arm64/kernel/smp.c | 4 +-
> arch/ia64/kernel/acpi.c | 12 +-
> arch/x86/kernel/acpi/boot.c | 36 +-
> drivers/acpi/Kconfig | 1 +
> drivers/acpi/Makefile | 1 +
> drivers/acpi/hmat/Kconfig | 9 +
> drivers/acpi/hmat/Makefile | 1 +
> drivers/acpi/hmat/hmat.c | 537 ++++++++++++++++++++++++++
> drivers/acpi/numa.c | 16 +-
> drivers/acpi/scan.c | 4 +-
> drivers/acpi/tables.c | 76 +++-
> drivers/base/Kconfig | 8 +
> drivers/base/node.c | 354 ++++++++++++++++-
> drivers/irqchip/irq-gic-v2m.c | 2 +-
> drivers/irqchip/irq-gic-v3-its-pci-msi.c | 2 +-
> drivers/irqchip/irq-gic-v3-its-platform-msi.c | 2 +-
> drivers/irqchip/irq-gic-v3-its.c | 6 +-
> drivers/irqchip/irq-gic-v3.c | 10 +-
> drivers/irqchip/irq-gic.c | 4 +-
> drivers/mailbox/pcc.c | 2 +-
> include/linux/acpi.h | 6 +-
> include/linux/node.h | 60 ++-
> 25 files changed, 1344 insertions(+), 65 deletions(-)
> create mode 100644 Documentation/admin-guide/mm/numaperf.rst
> create mode 100644 drivers/acpi/hmat/Kconfig
> create mode 100644 drivers/acpi/hmat/Makefile
> create mode 100644 drivers/acpi/hmat/hmat.c
>
> --
> 2.14.4

--
Michal Hocko
SUSE Labs