Reserve EFI Specific Purpose Memory
configname: CONFIG_EFI_SOFT_RESERVE
Linux Kernel Configuration
└─>Firmware Drivers
└─>EFI (Extensible Firmware Interface) Support
└─>Reserve EFI Specific Purpose Memory
In linux kernel since version 4.14.326 (release Date: 2023-09-23)
On systems that have mixed performance classes of memory EFI
may indicate specific purpose memory with an attribute (See
EFI_MEMORY_SP in UEFI 2.8). A memory range tagged with this
attribute may have unique performance characteristics compared
to the system's general purpose "System RAM" pool. On the
expectation that such memory has application specific usage,
and its base EFI memory type is "conventional" answer Y to
arrange for the kernel to reserve it as a "Soft Reserved"
resource, and set aside for direct-access (device-dax) by
default. The memory range can later be optionally assigned to
the page allocator by system administrator policy via the
device-dax kmem facility. Say N to have the kernel treat this
memory as "System RAM" by default.
If unsure, say Y.
may indicate specific purpose memory with an attribute (See
EFI_MEMORY_SP in UEFI 2.8). A memory range tagged with this
attribute may have unique performance characteristics compared
to the system's general purpose "System RAM" pool. On the
expectation that such memory has application specific usage,
and its base EFI memory type is "conventional" answer Y to
arrange for the kernel to reserve it as a "Soft Reserved"
resource, and set aside for direct-access (device-dax) by
default. The memory range can later be optionally assigned to
the page allocator by system administrator policy via the
device-dax kmem facility. Say N to have the kernel treat this
memory as "System RAM" by default.
If unsure, say Y.