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| author | Keith Busch <keith.busch@intel.com> | 2019-03-11 14:56:02 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-04 18:41:21 +0200 |
| commit | acc02a109b0497e917c83f986a89c51e47d0022c (patch) | |
| tree | d91c422777692d123a0f5d42b96b6e5c76fba566 /Documentation/ABI/stable | |
| parent | e1cf33aafb8462c7d0a0e6349925870316f040ee (diff) | |
| download | lwn-acc02a109b0497e917c83f986a89c51e47d0022c.tar.gz lwn-acc02a109b0497e917c83f986a89c51e47d0022c.zip | |
node: Add memory-side caching attributes
System memory may have caches to help improve access speed to frequently
requested address ranges. While the system provided cache is transparent
to the software accessing these memory ranges, applications can optimize
their own access based on cache attributes.
Provide a new API for the kernel to register these memory-side caches
under the memory node that provides it.
The new sysfs representation is modeled from the existing cpu cacheinfo
attributes, as seen from /sys/devices/system/cpu/<cpu>/cache/. Unlike CPU
cacheinfo though, the node cache level is reported from the view of the
memory. A higher level number is nearer to the CPU, while lower levels
are closer to the last level memory.
The exported attributes are the cache size, the line size, associativity
indexing, and write back policy, and add the attributes for the system
memory caches to sysfs stable documentation.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Brice Goglin <Brice.Goglin@inria.fr>
Tested-by: Brice Goglin <Brice.Goglin@inria.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/ABI/stable')
| -rw-r--r-- | Documentation/ABI/stable/sysfs-devices-node | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node index 735a40a3f9b2..f7ce68fbd4b9 100644 --- a/Documentation/ABI/stable/sysfs-devices-node +++ b/Documentation/ABI/stable/sysfs-devices-node @@ -142,3 +142,37 @@ Contact: Keith Busch <keith.busch@intel.com> Description: This node's write latency in nanoseconds when access from nodes found in this class's linked initiators. + +What: /sys/devices/system/node/nodeX/memory_side_cache/indexY/ +Date: December 2018 +Contact: Keith Busch <keith.busch@intel.com> +Description: + The directory containing attributes for the memory-side cache + level 'Y'. + +What: /sys/devices/system/node/nodeX/memory_side_cache/indexY/indexing +Date: December 2018 +Contact: Keith Busch <keith.busch@intel.com> +Description: + The caches associativity indexing: 0 for direct mapped, + non-zero if indexed. + +What: /sys/devices/system/node/nodeX/memory_side_cache/indexY/line_size +Date: December 2018 +Contact: Keith Busch <keith.busch@intel.com> +Description: + The number of bytes accessed from the next cache level on a + cache miss. + +What: /sys/devices/system/node/nodeX/memory_side_cache/indexY/size +Date: December 2018 +Contact: Keith Busch <keith.busch@intel.com> +Description: + The size of this memory side cache in bytes. + +What: /sys/devices/system/node/nodeX/memory_side_cache/indexY/write_policy +Date: December 2018 +Contact: Keith Busch <keith.busch@intel.com> +Description: + The cache write policy: 0 for write-back, 1 for write-through, + other or unknown. |