summaryrefslogtreecommitdiff
path: root/mm/Kconfig
diff options
context:
space:
mode:
Diffstat (limited to 'mm/Kconfig')
-rw-r--r--mm/Kconfig82
1 files changed, 44 insertions, 38 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index 25c71eb8a7db..ee8d1f311858 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -11,23 +11,24 @@ choice
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.
@@ -38,29 +39,26 @@ config DISCONTIGMEM_MANUAL
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
@@ -136,7 +134,7 @@ config HAVE_MEMBLOCK_PHYS_MAP
config HAVE_GENERIC_GUP
bool
-config ARCH_DISCARD_MEMBLOCK
+config ARCH_KEEP_MEMBLOCK
bool
config MEMORY_ISOLATION
@@ -161,7 +159,6 @@ config MEMORY_HOTPLUG_SPARSE
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
@@ -258,6 +255,9 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION
config ARCH_ENABLE_THP_MIGRATION
bool
+config CONTIG_ALLOC
+ def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
+
config PHYS_ADDR_T_64BIT
def_bool 64BIT
@@ -436,7 +436,6 @@ config NEED_PER_CPU_KM
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
@@ -460,7 +459,6 @@ config CLEANCACHE
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
@@ -532,7 +530,6 @@ config ZSWAP
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
@@ -549,14 +546,12 @@ config ZSWAP
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
@@ -567,7 +562,6 @@ config ZBUD
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
@@ -577,7 +571,6 @@ config Z3FOLD
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
@@ -628,7 +621,6 @@ config MAX_STACK_SIZE_MB
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
@@ -676,6 +668,22 @@ config ZONE_DEVICE
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
@@ -694,12 +702,12 @@ config DEV_PAGEMAP_OPS
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
@@ -740,7 +748,6 @@ config ARCH_HAS_PKEYS
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
@@ -748,7 +755,6 @@ config PERCPU_STATS
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().