@@ -28,7 +28,8 @@ endif
man1_MANS = \
daxctl.1 \
daxctl-list.1 \
- daxctl-migrate-device-model.1
+ daxctl-migrate-device-model.1 \
+ daxctl-reconfigure-device.1
CLEANFILES = $(man1_MANS)
new file mode 100644
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+
+daxctl-reconfigure-device(1)
+============================
+
+NAME
+----
+daxctl-reconfigure-device - Reconfigure a dax device into a different mode
+
+SYNOPSIS
+--------
+[verse]
+'daxctl reconfigure-device' <dax0.0> [<dax1.0>...<daxY.Z>] [<options>]
+
+EXAMPLES
+--------
+
+* Reconfigure dax0.0 to system-ram mode, don't online the memory
+----
+# daxctl reconfigure-device --mode=system-ram --no-online dax0.0
+[
+ {
+ "chardev":"dax0.0",
+ "size":16777216000,
+ "target_node":2,
+ "mode":"system-ram"
+ }
+]
+----
+
+* Reconfigure dax0.0 to devdax mode, attempt to offline the memory
+----
+# daxctl reconfigure-device --human --mode=devdax --force dax0.0
+{
+ "chardev":"dax0.0",
+ "size":"15.63 GiB (16.78 GB)",
+ "target_node":2,
+ "mode":"devdax"
+}
+----
+
+* Reconfigure all dax devices on region0 to system-ram mode
+----
+# daxctl reconfigure-device --mode=system-ram --region=0 all
+[
+ {
+ "chardev":"dax0.0",
+ "size":16777216000,
+ "target_node":2,
+ "mode":"system-ram"
+ },
+ {
+ "chardev":"dax0.1",
+ "size":16777216000,
+ "target_node":3,
+ "mode":"system-ram"
+ }
+]
+----
+
+* Run a process called 'some-service' using numactl to restrict its cpu
+nodes to '0' and '1', and memory allocations to node 2 (determined using
+daxctl_dev_get_target_node() or 'daxctl list')
+----
+# daxctl reconfigure-device --mode=system-ram dax0.0
+[
+ {
+ "chardev":"dax0.0",
+ "size":16777216000,
+ "target_node":2,
+ "mode":"system-ram"
+ }
+]
+
+# numactl --cpunodebind=0-1 --membind=2 -- some-service --opt1 --opt2
+----
+
+DESCRIPTION
+-----------
+
+Reconfigure the operational mode of a dax device. This can be used to convert
+a regular 'devdax' mode device to the 'system-ram' mode which arranges for the
+dax range to be hot-plugged into the system as regular memory.
+
+NOTE: This is a destructive operation. Any data on the dax device *will* be
+lost.
+
+NOTE: Device reconfiguration depends on the dax-bus device model. See
+linkdaxctl:daxctl-migrate-device-model[1] for more information. If dax-class is
+in use (via the dax_pmem_compat driver), the reconfiguration will fail with an
+error such as the following:
+----
+# daxctl reconfigure-device --mode=system-ram --region=0 all
+libdaxctl: daxctl_dev_disable: dax3.0: error: device model is dax-class
+dax3.0: disable failed: Operation not supported
+error reconfiguring devices: Operation not supported
+reconfigured 0 devices
+----
+
+OPTIONS
+-------
+-r::
+--region=::
+ Restrict the operation to devices belonging to the specified region(s).
+ A device-dax region is a contiguous range of memory that hosts one or
+ more /dev/daxX.Y devices, where X is the region id and Y is the device
+ instance id.
+
+-m::
+--mode=::
+ Specify the mode to which the dax device(s) should be reconfigured.
+ - "system-ram": hotplug the device into system memory.
+
+ - "devdax": switch to the normal "device dax" mode. This requires the
+ kernel to support hot-unplugging 'kmem' based memory. If this is not
+ available, a reboot is the only way to switch back to 'devdax' mode.
+
+-N::
+--no-online::
+ By default, memory sections provided by system-ram devices will be
+ brought online automatically and immediately with the 'online_movable'
+ policy. Use this option to disable the automatic onlining behavior.
+
+ NOTE: While this option prevents daxctl from automatically onlining
+ the memory sections, there may be other agents, notably system udev
+ rules, that online new memory sections as they appear. Coordinating
+ with such rules is out of scope of this utility, and the system
+ administrator is expected to remove them if they are undesirable.
+ If such an agent races to online memory sections, daxctl is prepared
+ to lose the race, and not fail the onlining operation as it only
+ cares that the memory section was onlined, not that it was the one
+ to do so.
+
+-f::
+--force::
+ When converting from "system-ram" mode to "devdax", it is expected
+ that all the memory sections are first made offline. By default,
+ daxctl won't touch online memory. However with this option, attempt
+ to offline the memory on the NUMA node associated with the dax device
+ before converting it back to "devdax" mode.
+
+-u::
+--human::
+ By default the command will output machine-friendly raw-integer
+ data. Instead, with this flag, numbers representing storage size
+ will be formatted as human readable strings with units, other
+ fields are converted to hexadecimal strings.
+
+-v::
+--verbose::
+ Emit more debug messages
+
+include::../copyright.txt[]
+
+SEE ALSO
+--------
+linkdaxctl:daxctl-list[1],daxctl-migrate-device-model[1]
Add a man page describing the new daxctl-reconfigure-device command. Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@intel.com> --- Documentation/daxctl/Makefile.am | 3 +- .../daxctl/daxctl-reconfigure-device.txt | 157 ++++++++++++++++++ 2 files changed, 159 insertions(+), 1 deletion(-) create mode 100644 Documentation/daxctl/daxctl-reconfigure-device.txt