+# SPDX-License-Identifier: GPL-2.0-only
menu "Memory Management options"
default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT
default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
default FLATMEM_MANUAL
+ help
+ This option allows you to change some of the ways that
+ Linux manages its memory internally. Most users will
+ only have one option here selected by the architecture
+ configuration. This is normal.
config FLATMEM_MANUAL
bool "Flat Memory"
depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE
help
- This option allows you to change some of the ways that
- Linux manages its memory internally. Most users will
- only have one option here: FLATMEM. This is normal
- and a correct option.
-
- Some users of more advanced features like NUMA and
- memory hotplug may have different options here.
- DISCONTIGMEM is a more mature, better tested system,
- but is incompatible with memory hotplug and may suffer
- decreased performance over SPARSEMEM. If unsure between
- "Sparse Memory" and "Discontiguous Memory", choose
- "Discontiguous Memory".
+ This option is best suited for non-NUMA systems with
+ flat address space. The FLATMEM is the most efficient
+ system in terms of performance and resource consumption
+ and it is the best option for smaller systems.
+
+ For systems that have holes in their physical address
+ spaces and for features like NUMA and memory hotplug,
+ choose "Sparse Memory"
If unsure, choose this option (Flat Memory) over any other.
This option provides enhanced support for discontiguous
memory systems, over FLATMEM. These systems have holes
in their physical address spaces, and this option provides
- more efficient handling of these holes. However, the vast
- majority of hardware has quite flat address spaces, and
- can have degraded performance from the extra overhead that
- this option imposes.
+ more efficient handling of these holes.
- Many NUMA configurations will have this as the only option.
+ Although "Discontiguous Memory" is still used by several
+ architectures, it is considered deprecated in favor of
+ "Sparse Memory".
- If unsure, choose "Flat Memory" over this option.
+ If unsure, choose "Sparse Memory" over this option.
config SPARSEMEM_MANUAL
bool "Sparse Memory"
depends on ARCH_SPARSEMEM_ENABLE
help
This will be the only option for some systems, including
- memory hotplug systems. This is normal.
+ memory hot-plug systems. This is normal.
- For many other systems, this will be an alternative to
- "Discontiguous Memory". This option provides some potential
- performance benefits, along with decreased code complexity,
- but it is newer, and more experimental.
+ This option provides efficient support for systems with
+ holes is their physical address space and allows memory
+ hot-plug and hot-remove.
- If unsure, choose "Discontiguous Memory" or "Flat Memory"
- over this option.
+ If unsure, choose "Flat Memory" over this option.
endchoice
config HAVE_GENERIC_GUP
bool
-config ARCH_DISCARD_MEMBLOCK
+config ARCH_KEEP_MEMBLOCK
bool
config MEMORY_ISOLATION
config MEMORY_HOTPLUG_DEFAULT_ONLINE
bool "Online the newly added memory blocks by default"
- default n
depends on MEMORY_HOTPLUG
help
This option sets the default policy setting for memory hotplug
config ARCH_ENABLE_THP_MIGRATION
bool
+config CONTIG_ALLOC
+ def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
+
config PHYS_ADDR_T_64BIT
def_bool 64BIT
config CLEANCACHE
bool "Enable cleancache driver to cache clean pages if tmem is present"
- default n
help
Cleancache can be thought of as a page-granularity victim cache
for clean pages that the kernel's pageframe replacement algorithm
config FRONTSWAP
bool "Enable frontswap to cache swap pages if tmem is present"
depends on SWAP
- default n
help
Frontswap is so named because it can be thought of as the opposite
of a "backing" store for a swap device. The data is stored into
depends on FRONTSWAP && CRYPTO=y
select CRYPTO_LZO
select ZPOOL
- default n
help
A lightweight compressed cache for swap pages. It takes
pages that are in the process of being swapped out and attempts to
config ZPOOL
tristate "Common API for compressed memory storage"
- default n
help
Compressed memory storage API. This allows using either zbud or
zsmalloc.
config ZBUD
tristate "Low (Up to 2x) density storage for compressed pages"
- default n
help
A special purpose allocator for storing compressed pages.
It is designed to store up to two compressed pages per physical
config Z3FOLD
tristate "Up to 3x density storage for compressed pages"
depends on ZPOOL
- default n
help
A special purpose allocator for storing compressed pages.
It is designed to store up to three compressed pages per physical
config ZSMALLOC
tristate "Memory allocator for compressed pages"
depends on MMU
- default n
help
zsmalloc is a slab-based memory allocator designed to store
compressed RAM pages. zsmalloc uses virtual memory mapping
config DEFERRED_STRUCT_PAGE_INIT
bool "Defer initialisation of struct pages to kthreads"
- default n
depends on SPARSEMEM
depends on !NEED_PER_CPU_KM
depends on 64BIT
If FS_DAX is enabled, then say Y.
+config ARCH_HAS_HMM_MIRROR
+ bool
+ default y
+ depends on (X86_64 || PPC64)
+ depends on MMU && 64BIT
+
+config ARCH_HAS_HMM_DEVICE
+ bool
+ default y
+ depends on (X86_64 || PPC64)
+ depends on MEMORY_HOTPLUG
+ depends on MEMORY_HOTREMOVE
+ depends on SPARSEMEM_VMEMMAP
+ depends on ARCH_HAS_ZONE_DEVICE
+ select XARRAY_MULTI
+
config ARCH_HAS_HMM
bool
default y
config HMM
bool
+ select MMU_NOTIFIER
select MIGRATE_VMA_HELPER
config HMM_MIRROR
bool "HMM mirror CPU page table into a device page table"
depends on ARCH_HAS_HMM
- select MMU_NOTIFIER
select HMM
help
Select HMM_MIRROR if you want to mirror range of the CPU page table of a
config PERCPU_STATS
bool "Collect percpu memory statistics"
- default n
help
This feature collects and exposes statistics via debugfs. The
information includes global and per chunk statistics, which can
config GUP_BENCHMARK
bool "Enable infrastructure for get_user_pages_fast() benchmarking"
- default n
help
Provides /sys/kernel/debug/gup_benchmark that helps with testing
performance of get_user_pages_fast().
projects / linux-2.6-microblaze.git / blobdiff