[PATCH v4 0/5] powerpc/mm: movable hotplug memory nodes

From: Reza Arbab
Date: Thu Oct 06 2016 - 14:37:14 EST

These changes enable the dynamic creation of movable nodes on power.

On x86, the ACPI SRAT memory affinity structure can mark memory
hotpluggable, allowing the kernel to possibly create movable nodes at

While power has no analog of this SRAT information, we can still create
a movable memory node, post boot, by hotplugging all of the node's
memory into ZONE_MOVABLE.

We provide a way to describe the extents and numa associativity of such
a node in the device tree, while deferring the memory addition to take
place through hotplug.

In v1, this patchset introduced a new dt compatible id to explicitly
create a memoryless node at boot. Here, things have been simplified to
be applicable regardless of the status of node hotplug on power. We
still intend to enable hotadding a pgdat, but that's now untangled as a
separate topic.

* Rename of_fdt_is_available() to of_fdt_device_is_available().
Rename of_flat_dt_is_available() to of_flat_dt_device_is_available().

* Instead of restoring top-down allocation, ensure it never goes
bottom-up in the first place, by making movable_node arch-specific.

* Use MEMORY_HOTPLUG instead of PPC64 in the mm/Kconfig patch.

* http://lkml.kernel.org/r/1474828616-16608-1-git-send-email-arbab@xxxxxxxxxxxxxxxxxx

* Use Rob Herring's suggestions to improve the node availability check.

* More verbose commit log in the patch enabling CONFIG_MOVABLE_NODE.

* Add a patch to restore top-down allocation the way x86 does.

* http://lkml.kernel.org/r/1473883618-14998-1-git-send-email-arbab@xxxxxxxxxxxxxxxxxx

* Use the "status" property of standard dt memory nodes instead of
introducing a new "ibm,hotplug-aperture" compatible id.

* Remove the patch which explicitly creates a memoryless node. This set
no longer has any bearing on whether the pgdat is created at boot or
at the time of memory addition.

* http://lkml.kernel.org/r/1470680843-28702-1-git-send-email-arbab@xxxxxxxxxxxxxxxxxx

Reza Arbab (5):
drivers/of: introduce of_fdt_device_is_available()
drivers/of: do not add memory for unavailable nodes
powerpc/mm: allow memory hotplug into a memoryless node
mm: make processing of movable_node arch-specific
mm: enable CONFIG_MOVABLE_NODE on non-x86 arches

arch/powerpc/mm/numa.c | 13 +------------
arch/x86/mm/numa.c | 35 ++++++++++++++++++++++++++++++++++-
drivers/of/fdt.c | 29 ++++++++++++++++++++++++++---
include/linux/of_fdt.h | 2 ++
mm/Kconfig | 2 +-
mm/memory_hotplug.c | 31 -------------------------------
6 files changed, 64 insertions(+), 48 deletions(-)