linux/arch/powerpc
Dan Williams 8fc5c73554 acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node
Persistent memory, as described by the ACPI NFIT (NVDIMM Firmware
Interface Table), is the first known instance of a memory range
described by a unique "target" proximity domain. Where "initiator" and
"target" proximity domains is an approach that the ACPI HMAT
(Heterogeneous Memory Attributes Table) uses to described the unique
performance properties of a memory range relative to a given initiator
(e.g. CPU or DMA device).

Currently the numa-node for a /dev/pmemX block-device or /dev/daxX.Y
char-device follows the traditional notion of 'numa-node' where the
attribute conveys the closest online numa-node. That numa-node attribute
is useful for cpu-binding and memory-binding processes *near* the
device. However, when the memory range backing a 'pmem', or 'dax' device
is onlined (memory hot-add) the memory-only-numa-node representing that
address needs to be differentiated from the set of online nodes. In
other words, the numa-node association of the device depends on whether
you can bind processes *near* the cpu-numa-node in the offline
device-case, or bind process *on* the memory-range directly after the
backing address range is onlined.

Allow for the case that platform firmware describes persistent memory
with a unique proximity domain, i.e. when it is distinct from the
proximity of DRAM and CPUs that are on the same socket. Plumb the Linux
numa-node translation of that proximity through the libnvdimm region
device to namespaces that are in device-dax mode. With this in place the
proposed kmem driver [1] can optionally discover a unique numa-node
number for the address range as it transitions the memory from an
offline state managed by a device-driver to an online memory range
managed by the core-mm.

[1]: https://lore.kernel.org/lkml/20181022201317.8558C1D8@viggo.jf.intel.com

Reported-by: Fan Du <fan.du@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2019-01-06 21:41:57 -08:00
..
boot Kbuild updates for v4.21 2018-12-29 12:03:17 -08:00
configs powerpc/configs: Add PPC4xx_OCM to ppc40x_defconfig 2018-12-30 14:00:47 +11:00
crypto powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
include arch: remove redundant UAPI generic-y defines 2019-01-06 10:22:15 +09:00
kernel jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kvm Merge branch 'master' into fixes 2019-01-04 22:07:47 +11:00
lib Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
math-emu
mm Merge branch 'akpm' (patches from Andrew) 2019-01-05 09:16:18 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-12-10 18:00:43 -08:00
oprofile Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
perf Powerpc/perf: Wire up PMI throttling 2018-12-21 11:32:49 +11:00
platforms acpi/nfit, device-dax: Identify differentiated memory with a unique numa-node 2019-01-06 21:41:57 -08:00
purgatory powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
sysdev Revert "powerpc/fsl_pci: simplify fsl_pci_dma_set_mask" 2018-12-23 20:11:20 -06:00
tools powerpc/tools/checkpatch: Ignore DT_SPLIT_BINDING_PATCH 2018-12-04 19:45:01 +11:00
xmon powerpc/xmon: fix dump_segments() 2018-12-19 18:56:32 +11:00
Kbuild powerpc: Add -Werror at arch/powerpc level 2018-10-19 00:56:17 +11:00
Kconfig Kconfig file consolidation for v4.21 2018-12-29 13:40:29 -08:00
Kconfig.debug powerpc: remove redundant 'default n' from Kconfig-s 2018-10-13 22:21:25 +11:00
Makefile powerpc updates for 4.21 2018-12-27 10:43:24 -08:00
Makefile.postlink