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authorDapeng Mi <dapeng1.mi@linux.intel.com>2026-09-17 09:52:33 +0800
committerIngo Molnar <mingo@kernel.org>2026-09-22 11:37:46 +0200
commit0102c8c7fdfc4bd700971daff2b94470f4eafae4 (patch)
tree531306c2299f9a269f0a986e29f17ba972180104 /Documentation/ABI/testing/sysfs-bus-dax
downloadlinux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.tar.gz
linux-stable-0102c8c7fdfc4bd700971daff2b94470f4eafae4.zip
perf/x86/intel: Rename DMR offcore_rsp attribute to offmodule_rspgrafted
DMR introduces Offmodule Response events in place of the legacy Offcore Response events, but it still exposes the inherited offcore_rsp PMU attribute for programming the corresponding MSR data. Rename the DMR PMU attribute to offmodule_rsp so the sysfs interface matches the underlying event name and avoids user & tooling confusion. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://patch.msgid.link/20260917015234.981153-12-dapeng1.mi@linux.intel.com
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+What: /sys/bus/dax/devices/daxX.Y/align
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RW) Provides a way to specify an alignment for a dax device.
+ Values allowed are constrained by the physical address ranges
+ that back the dax device, and also by arch requirements.
+
+What: /sys/bus/dax/devices/daxX.Y/mapping
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (WO) Provides a way to allocate a mapping range under a dax
+ device. Specified in the format <start>-<end>.
+
+What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/start
+What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/end
+What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/page_offset
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) A dax device may have multiple constituent discontiguous
+ address ranges. These are represented by the different
+ 'mappingX' subdirectories. The 'start' attribute indicates the
+ start physical address for the given range. The 'end' attribute
+ indicates the end physical address for the given range. The
+ 'page_offset' attribute indicates the offset of the current
+ range in the dax device.
+
+What: /sys/bus/dax/devices/daxX.Y/resource
+Date: June, 2019
+KernelVersion: v5.3
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) The resource attribute indicates the starting physical
+ address of a dax device. In case of a device with multiple
+ constituent ranges, it indicates the starting address of the
+ first range.
+
+What: /sys/bus/dax/devices/daxX.Y/size
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RW) The size attribute indicates the total size of a dax
+ device. For creating subdivided dax devices, or for resizing
+ an existing device, the new size can be written to this as
+ part of the reconfiguration process.
+
+What: /sys/bus/dax/devices/daxX.Y/numa_node
+Date: November, 2019
+KernelVersion: v5.5
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) If NUMA is enabled and the platform has affinitized the
+ backing device for this dax device, emit the CPU node
+ affinity for this device.
+
+What: /sys/bus/dax/devices/daxX.Y/target_node
+Date: February, 2019
+KernelVersion: v5.1
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) The target-node attribute is the Linux numa-node that a
+ device-dax instance may create when it is online. Prior to
+ being online the device's 'numa_node' property reflects the
+ closest online cpu node which is the typical expectation of a
+ device 'numa_node'. Once it is online it becomes its own
+ distinct numa node.
+
+What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/available_size
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) The available_size attribute tracks available dax region
+ capacity. This only applies to volatile hmem devices, not pmem
+ devices, since pmem devices are defined by nvdimm namespace
+ boundaries.
+
+What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/size
+Date: July, 2017
+KernelVersion: v5.1
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) The size attribute indicates the size of a given dax region
+ in bytes.
+
+What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/align
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) The align attribute indicates alignment of the dax region.
+ Changes on align may not always be valid, when say certain
+ mappings were created with 2M and then we switch to 1G. This
+ validates all ranges against the new value being attempted, post
+ resizing.
+
+What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/seed
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) The seed device is a concept for dynamic dax regions to be
+ able to split the region amongst multiple sub-instances. The
+ seed device, similar to libnvdimm seed devices, is a device
+ that starts with zero capacity allocated and unbound to a
+ driver.
+
+What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/create
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RW) The create interface to the dax region provides a way to
+ create a new unconfigured dax device under the given region, which
+ can then be configured (with a size etc.) and then probed.
+
+What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/delete
+Date: October, 2020
+KernelVersion: v5.10
+Contact: nvdimm@lists.linux.dev
+Description:
+ (WO) The delete interface for a dax region provides for deletion
+ of any 0-sized and idle dax devices.
+
+What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/id
+Date: July, 2017
+KernelVersion: v5.1
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RO) The id attribute indicates the region id of a dax region.
+
+What: /sys/bus/dax/devices/daxX.Y/memmap_on_memory
+Date: January, 2024
+KernelVersion: v6.8
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RW) Control the memmap_on_memory setting if the dax device
+ were to be hotplugged as system memory. This determines whether
+ the 'altmap' for the hotplugged memory will be placed on the
+ device being hotplugged (memmap_on_memory=1) or if it will be
+ placed on regular memory (memmap_on_memory=0). This attribute
+ must be set before the device is handed over to the 'kmem'
+ driver (i.e. hotplugged into system-ram). Additionally, this
+ depends on CONFIG_MHP_MEMMAP_ON_MEMORY, and a globally enabled
+ memmap_on_memory parameter for memory_hotplug. This is
+ typically set on the kernel command line -
+ memory_hotplug.memmap_on_memory set to 'true' or 'force'."
+
+What: /sys/bus/dax/devices/daxX.Y/state
+Contact: nvdimm@lists.linux.dev
+Description:
+ (RW) Controls the state of the memory region.
+ Applies to all memory blocks associated with the device.
+ Only applies to dax_kmem devices.
+
+ Reading returns the current state; the writable states mirror
+ the per-block /sys/devices/system/memory/memoryX/state ABI::
+
+ "unplugged": memory blocks are not present
+ "online": memory is online, zone chosen by the kernel
+ "online_kernel": memory is online in ZONE_NORMAL
+ "online_movable": memory is online in ZONE_MOVABLE
+
+ "offline" (memory blocks are present but offline) may also be
+ reported - this happens when the device is bound while the
+ auto_online_blocks policy is "offline". It cannot be written,
+ as it's not useful and creates device destruction races.
+
+ A device can only be onlined from the "unplugged" state, so a
+ device must be returned to "unplugged" before it can be onlined
+ into a different state.