CONFIG_ARM64_HW_AFDBM is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64
Support for hardware updates of the Access and Dirty page flags
configname: CONFIG_ARM64_HW_AFDBM
Linux Kernel Configuration
└─>Kernel Features
└─>ARMv8.1 architectural features
└─>Support for hardware updates of the Access and Dirty page flags
In linux kernel since version 4.1 (release Date: 2015-06-21)
The ARMv8.1 architecture extensions introduce support for
hardware updates of the access and dirty information in page
table entries. When enabled in TCR_EL1 (HA and HD bits) on
capable processors, accesses to pages with PTE_AF cleared will
set this bit instead of raising an access flag fault.
Similarly, writes to read-only pages with the DBM bit set will
clear the read-only bit (AP[2]) instead of raising a
permission fault.
Kernels built with this configuration option enabled continue
to work on pre-ARMv8.1 hardware and the performance impact is
minimal. If unsure, say Y.
hardware updates of the access and dirty information in page
table entries. When enabled in TCR_EL1 (HA and HD bits) on
capable processors, accesses to pages with PTE_AF cleared will
set this bit instead of raising an access flag fault.
Similarly, writes to read-only pages with the DBM bit set will
clear the read-only bit (AP[2]) instead of raising a
permission fault.
Kernels built with this configuration option enabled continue
to work on pre-ARMv8.1 hardware and the performance impact is
minimal. If unsure, say Y.