sysfs-bus-nfit

 1What:		/sys/bus/nd/devices/regionX/nfit/ecc_unit_size
 2Date:		Aug, 2017
 3KernelVersion:	v4.14 (Removed v4.18)
 4Contact:	nvdimm@lists.linux.dev
 5Description:
 6		(RO) Size of a write request to a DIMM that will not incur a
 7		read-modify-write cycle at the memory controller.
 8
 9		When the nfit driver initializes it runs an ARS (Address Range
10		Scrub) operation across every pmem range. Part of that process
11		involves determining the ARS capabilities of a given address
12		range. One of the capabilities that is reported is the 'Clear
13		Uncorrectable Error Range Length Unit Size' (see: ACPI 6.2
14		section 9.20.7.4 Function Index 1 - Query ARS Capabilities).
15		This property indicates the boundary at which the NVDIMM may
16		need to perform read-modify-write cycles to maintain ECC (Error
17		Correcting Code) blocks.