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authorKeith Busch <keith.busch@intel.com>2019-03-11 14:56:01 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-04-04 18:41:21 +0200
commite1cf33aafb8462c7d0a0e6349925870316f040ee (patch)
treea45159a6e1d29d976957ec619c57ee296c421a3a /drivers/base/Kconfig
parent08d9dbe72b1f899468b2b34f9309e88a84f440f2 (diff)
downloadlinux-e1cf33aafb8462c7d0a0e6349925870316f040ee.tar.bz2
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/Kconfig8
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