blob: ae8c1ca53828792274cc680bb01d15f8411edc79 [file] [log] [blame]
What: /sys/bus/nd/devices/regionX/nfit/ecc_unit_size
Date: Aug, 2017
KernelVersion: v4.14 (Removed v4.18)
(RO) Size of a write request to a DIMM that will not incur a
read-modify-write cycle at the memory controller.
When the nfit driver initializes it runs an ARS (Address Range
Scrub) operation across every pmem range. Part of that process
involves determining the ARS capabilities of a given address
range. One of the capabilities that is reported is the 'Clear
Uncorrectable Error Range Length Unit Size' (see: ACPI 6.2
section Function Index 1 - Query ARS Capabilities).
This property indicates the boundary at which the NVDIMM may
need to perform read-modify-write cycles to maintain ECC (Error
Correcting Code) blocks.