1 What: /sys/bus/nd/devices/regionX/nf 1 What: /sys/bus/nd/devices/regionX/nfit/ecc_unit_size
2 Date: Aug, 2017 2 Date: Aug, 2017
3 KernelVersion: v4.14 (Removed v4.18) 3 KernelVersion: v4.14 (Removed v4.18)
4 Contact: nvdimm@lists.linux.dev !! 4 Contact: linux-nvdimm@lists.01.org
5 Description: 5 Description:
6 (RO) Size of a write request t 6 (RO) Size of a write request to a DIMM that will not incur a
7 read-modify-write cycle at the 7 read-modify-write cycle at the memory controller.
8 8
9 When the nfit driver initializ 9 When the nfit driver initializes it runs an ARS (Address Range
10 Scrub) operation across every 10 Scrub) operation across every pmem range. Part of that process
11 involves determining the ARS c 11 involves determining the ARS capabilities of a given address
12 range. One of the capabilities 12 range. One of the capabilities that is reported is the 'Clear
13 Uncorrectable Error Range Leng 13 Uncorrectable Error Range Length Unit Size' (see: ACPI 6.2
14 section 9.20.7.4 Function Inde 14 section 9.20.7.4 Function Index 1 - Query ARS Capabilities).
15 This property indicates the bo 15 This property indicates the boundary at which the NVDIMM may
16 need to perform read-modify-wr 16 need to perform read-modify-write cycles to maintain ECC (Error
17 Correcting Code) blocks. 17 Correcting Code) blocks.
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