NAME

       ndctl-wait-scrub - wait for an Address Range Scrub (ARS) operation to complete

SYNOPSIS

       ndctl wait-scrub [<bus-id> <bus-id2> ... <bus-idN>] [<options>]

DESCRIPTION

       NVDIMM Address Range Scrub is a capability provided by platform firmware that allows for
       the discovery of memory errors by system software. It enables system software to
       pre-emptively avoid accesses that could lead to uncorrectable memory error handling
       events, and it otherwise allows memory errors to be enumerated.

       The kernel provides a POLL(2) capable sysfs file (scrub) to indicate the state of ARS. The
       scrub file maintains a running count of ARS runs that have taken place. While a current
       run is in progress a + character is emitted along with the current count. The ndctl
       wait-scrub operation waits for scrub, across all specified buses, to indicate not
       in-progress at least once.

EXAMPLE

       Wait for scrub on all nvdimm buses in the system. The json listing report at the end only
       includes the buses that support ARS operations.

           .ft C
           # ndctl wait-scrub
           [
             {
               "provider":"nfit_test.1",
               "dev":"ndbus3",
               "scrub_state":"idle"
             },
             {
               "provider":"nfit_test.0",
               "dev":"ndbus2",
               "scrub_state":"idle"
             }
           ]
           .ft

       When specifying an individual bus, or if there is only one bus in the system, the command
       reports whether ARS support is available.

           .ft C
           # ndctl wait-scrub e820
           error waiting for scrub completion: Operation not supported
           .ft

OPTIONS

       -v, --verbose
           Emit debug messages for the ARS wait process

COPYRIGHT

       Copyright (c) 2016 - 2018, Intel Corporation. License GPLv2: GNU GPL version 2
       http://gnu.org/licenses/gpl.html. This is free software: you are free to change and
       redistribute it. There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

       ndctl-start-scrub(1), ACPI 6.2 Specification Section 9.20.7.2 Address Range Scrubbing
       (ARS) Overview[1]

NOTES

        1. ACPI 6.2 Specification Section 9.20.7.2 Address Range Scrubbing (ARS) Overview
           http://www.uefi.org/sites/default/files/resources/ACPI%206_2_A_Sept29.pdf