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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 /include/linux/acpi.h
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 'include/linux/acpi.h')
-rw-r--r--include/linux/acpi.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 87715f20b69a..eddf2736e5a6 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -400,12 +400,17 @@ extern bool acpi_osi_is_win8(void);
#ifdef CONFIG_ACPI_NUMA
int acpi_map_pxm_to_online_node(int pxm);
+int acpi_map_pxm_to_node(int pxm);
int acpi_get_node(acpi_handle handle);
#else
static inline int acpi_map_pxm_to_online_node(int pxm)
{
return 0;
}
+static inline int acpi_map_pxm_to_node(int pxm)
+{
+ return 0;
+}
static inline int acpi_get_node(acpi_handle handle)
{
return 0;