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| author | Dan Williams <dan.j.williams@intel.com> | 2018-11-09 23:43:07 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2019-01-07 08:41:57 +0300 |
| commit | 8fc5c73554db0ac18c0c6ac5b2099ab917f83bdf (patch) | |
| tree | 6e6ef5bfbea9e4a63a784f658b9e7138e278be34 /drivers/dax/bus.h | |
| parent | 730926c3b0998943654019f00296cf8e3b02277e (diff) | |
| download | linux-8fc5c73554db0ac18c0c6ac5b2099ab917f83bdf.tar.xz | |
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/dax/bus.h')
| -rw-r--r-- | drivers/dax/bus.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index ce977552ffb5..8619e3299943 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -10,7 +10,8 @@ struct dax_device; struct dax_region; void dax_region_put(struct dax_region *dax_region); struct dax_region *alloc_dax_region(struct device *parent, int region_id, - struct resource *res, unsigned int align, unsigned long flags); + struct resource *res, int target_node, unsigned int align, + unsigned long flags); enum dev_dax_subsys { DEV_DAX_BUS, |