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authorDan Williams <dan.j.williams@intel.com>2018-11-09 12:43:07 -0800
committerDan Williams <dan.j.williams@intel.com>2019-01-06 21:41:57 -0800
commit8fc5c73554db0ac18c0c6ac5b2099ab917f83bdf (patch)
tree6e6ef5bfbea9e4a63a784f658b9e7138e278be34 /drivers/acpi
parent730926c3b0998943654019f00296cf8e3b02277e (diff)
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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>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/nfit/core.c8
-rw-r--r--drivers/acpi/numa.c1
2 files changed, 7 insertions, 2 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 011d3db19c80..475899974c70 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2869,11 +2869,15 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
ndr_desc->res = &res;
ndr_desc->provider_data = nfit_spa;
ndr_desc->attr_groups = acpi_nfit_region_attribute_groups;
- if (spa->flags & ACPI_NFIT_PROXIMITY_VALID)
+ if (spa->flags & ACPI_NFIT_PROXIMITY_VALID) {
ndr_desc->numa_node = acpi_map_pxm_to_online_node(
spa->proximity_domain);
- else
+ ndr_desc->target_node = acpi_map_pxm_to_node(
+ spa->proximity_domain);
+ } else {
ndr_desc->numa_node = NUMA_NO_NODE;
+ ndr_desc->target_node = NUMA_NO_NODE;
+ }
/*
* Persistence domain bits are hierarchical, if
diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index 274699463b4f..b9d86babb13a 100644
--- a/drivers/acpi/numa.c
+++ b/drivers/acpi/numa.c
@@ -84,6 +84,7 @@ int acpi_map_pxm_to_node(int pxm)
return node;
}
+EXPORT_SYMBOL(acpi_map_pxm_to_node);
/**
* acpi_map_pxm_to_online_node - Map proximity ID to online node