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| author | Keith Busch <keith.busch@intel.com> | 2019-03-11 14:56:01 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-04 18:41:21 +0200 |
| commit | e1cf33aafb8462c7d0a0e6349925870316f040ee (patch) | |
| tree | a45159a6e1d29d976957ec619c57ee296c421a3a /drivers/base/Kconfig | |
| parent | 08d9dbe72b1f899468b2b34f9309e88a84f440f2 (diff) | |
| download | linux-rpi-e1cf33aafb8462c7d0a0e6349925870316f040ee.tar.gz linux-rpi-e1cf33aafb8462c7d0a0e6349925870316f040ee.tar.bz2 linux-rpi-e1cf33aafb8462c7d0a0e6349925870316f040ee.zip | |
node: Add heterogenous memory access attributes
Heterogeneous memory systems provide memory nodes with different latency
and bandwidth performance attributes. Provide a new kernel interface
for subsystems to register the attributes under the memory target
node's initiator access class. If the system provides this information,
applications may query these attributes when deciding which node to
request memory.
The following example shows the new sysfs hierarchy for a node exporting
performance attributes:
# tree -P "read*|write*"/sys/devices/system/node/nodeY/accessZ/initiators/
/sys/devices/system/node/nodeY/accessZ/initiators/
|-- read_bandwidth
|-- read_latency
|-- write_bandwidth
`-- write_latency
The bandwidth is exported as MB/s and latency is reported in
nanoseconds. The values are taken from the platform as reported by the
manufacturer.
Memory accesses from an initiator node that is not one of the memory's
access "Z" initiator nodes linked in the same directory may observe
different performance than reported here. When a subsystem makes use
of this interface, initiators of a different access number may not have
the same performance relative to initiators in other access numbers, or
omitted from the any access class' initiators.
Descriptions for memory access initiator performance access attributes
are added to sysfs stable documentation.
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Brice Goglin <Brice.Goglin@inria.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/Kconfig')
| -rw-r--r-- | drivers/base/Kconfig | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig index 9fb2c4c92340..1d47ab987413 100644 --- a/drivers/base/Kconfig +++ b/drivers/base/Kconfig @@ -148,6 +148,14 @@ config DEBUG_TEST_DRIVER_REMOVE unusable. You should say N here unless you are explicitly looking to test this functionality. +config HMEM_REPORTING + bool + default n + depends on NUMA + help + Enable reporting for heterogenous memory access attributes under + their non-uniform memory nodes. + source "drivers/base/test/Kconfig" config SYS_HYPERVISOR |