Commit 519bcb79 authored by Johannes Weiner's avatar Johannes Weiner Committed by Andrew Morton
Browse files

mm: Kconfig: group swap, slab, hotplug and thp options into submenus 

There are several clusters of related config options spread throughout the
mostly flat MM submenu.  Group them together and put specialization
options into further subdirectories to make the MM submenu a bit more
organized and easier to navigate.

[hannes@cmpxchg.org: fix kbuild warnings]
  Link: https://lkml.kernel.org/r/YnvkSVivfnT57Vwh@cmpxchg.org
[hannes@cmpxchg.org: fix more kbuild warnings]
  Link: https://lkml.kernel.org/r/Ynz8NusTdEGcCnJN@cmpxchg.org
Link: https://lkml.kernel.org/r/20220510152847.230957-4-hannes@cmpxchg.org


Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 7b42f104

mm/Kconfig

+230 −217
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ menu "Memory Management options" 
config ARCH_NO_SWAP

	bool



config SWAP

menuconfig SWAP

	bool "Support for paging of anonymous memory (swap)"

	depends on MMU && BLOCK && !ARCH_NO_SWAP

	default y
@@ -19,6 +19,191 @@ config SWAP 
	  used to provide more virtual memory than the actual RAM present

	  in your computer.  If unsure say Y.



config ZSWAP

	bool "Compressed cache for swap pages (EXPERIMENTAL)"

	depends on SWAP && CRYPTO=y

	select FRONTSWAP

	select ZPOOL

	help

	  A lightweight compressed cache for swap pages.  It takes

	  pages that are in the process of being swapped out and attempts to

	  compress them into a dynamically allocated RAM-based memory pool.

	  This can result in a significant I/O reduction on swap device and,

	  in the case where decompressing from RAM is faster that swap device

	  reads, can also improve workload performance.



	  This is marked experimental because it is a new feature (as of

	  v3.11) that interacts heavily with memory reclaim.  While these

	  interactions don't cause any known issues on simple memory setups,

	  they have not be fully explored on the large set of potential

	  configurations and workloads that exist.



choice

	prompt "Compressed cache for swap pages default compressor"

	depends on ZSWAP

	default ZSWAP_COMPRESSOR_DEFAULT_LZO

	help

	  Selects the default compression algorithm for the compressed cache

	  for swap pages.



	  For an overview what kind of performance can be expected from

	  a particular compression algorithm please refer to the benchmarks

	  available at the following LWN page:

	  https://lwn.net/Articles/751795/



	  If in doubt, select 'LZO'.



	  The selection made here can be overridden by using the kernel

	  command line 'zswap.compressor=' option.



config ZSWAP_COMPRESSOR_DEFAULT_DEFLATE

	bool "Deflate"

	select CRYPTO_DEFLATE

	help

	  Use the Deflate algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_LZO

	bool "LZO"

	select CRYPTO_LZO

	help

	  Use the LZO algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_842

	bool "842"

	select CRYPTO_842

	help

	  Use the 842 algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_LZ4

	bool "LZ4"

	select CRYPTO_LZ4

	help

	  Use the LZ4 algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_LZ4HC

	bool "LZ4HC"

	select CRYPTO_LZ4HC

	help

	  Use the LZ4HC algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_ZSTD

	bool "zstd"

	select CRYPTO_ZSTD

	help

	  Use the zstd algorithm as the default compression algorithm.

endchoice



config ZSWAP_COMPRESSOR_DEFAULT

       string

       depends on ZSWAP

       default "deflate" if ZSWAP_COMPRESSOR_DEFAULT_DEFLATE

       default "lzo" if ZSWAP_COMPRESSOR_DEFAULT_LZO

       default "842" if ZSWAP_COMPRESSOR_DEFAULT_842

       default "lz4" if ZSWAP_COMPRESSOR_DEFAULT_LZ4

       default "lz4hc" if ZSWAP_COMPRESSOR_DEFAULT_LZ4HC

       default "zstd" if ZSWAP_COMPRESSOR_DEFAULT_ZSTD

       default ""



choice

	prompt "Compressed cache for swap pages default allocator"

	depends on ZSWAP

	default ZSWAP_ZPOOL_DEFAULT_ZBUD

	help

	  Selects the default allocator for the compressed cache for

	  swap pages.

	  The default is 'zbud' for compatibility, however please do

	  read the description of each of the allocators below before

	  making a right choice.



	  The selection made here can be overridden by using the kernel

	  command line 'zswap.zpool=' option.



config ZSWAP_ZPOOL_DEFAULT_ZBUD

	bool "zbud"

	select ZBUD

	help

	  Use the zbud allocator as the default allocator.



config ZSWAP_ZPOOL_DEFAULT_Z3FOLD

	bool "z3fold"

	select Z3FOLD

	help

	  Use the z3fold allocator as the default allocator.



config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC

	bool "zsmalloc"

	select ZSMALLOC

	help

	  Use the zsmalloc allocator as the default allocator.

endchoice



config ZSWAP_ZPOOL_DEFAULT

       string

       depends on ZSWAP

       default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD

       default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD

       default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC

       default ""



config ZSWAP_DEFAULT_ON

	bool "Enable the compressed cache for swap pages by default"

	depends on ZSWAP

	help

	  If selected, the compressed cache for swap pages will be enabled

	  at boot, otherwise it will be disabled.



	  The selection made here can be overridden by using the kernel

	  command line 'zswap.enabled=' option.



config ZPOOL

	tristate "Common API for compressed memory storage"

	depends on ZSWAP

	help

	  Compressed memory storage API.  This allows using either zbud or

	  zsmalloc.



config ZBUD

	tristate "Low (Up to 2x) density storage for compressed pages"

	depends on ZPOOL

	help

	  A special purpose allocator for storing compressed pages.

	  It is designed to store up to two compressed pages per physical

	  page.  While this design limits storage density, it has simple and

	  deterministic reclaim properties that make it preferable to a higher

	  density approach when reclaim will be used.



config Z3FOLD

	tristate "Up to 3x density storage for compressed pages"

	depends on ZPOOL

	help

	  A special purpose allocator for storing compressed pages.

	  It is designed to store up to three compressed pages per physical

	  page. It is a ZBUD derivative so the simplicity and determinism are

	  still there.



config ZSMALLOC

	tristate "Memory allocator for compressed pages"

	depends on MMU

	help

	  zsmalloc is a slab-based memory allocator designed to store

	  compressed RAM pages.  zsmalloc uses virtual memory mapping

	  in order to reduce fragmentation.  However, this results in a

	  non-standard allocator interface where a handle, not a pointer, is

	  returned by an alloc().  This handle must be mapped in order to

	  access the allocated space.



config ZSMALLOC_STAT

	bool "Export zsmalloc statistics"

	depends on ZSMALLOC

	select DEBUG_FS

	help

	  This option enables code in the zsmalloc to collect various

	  statistics about what's happening in zsmalloc and exports that

	  information to userspace via debugfs.

	  If unsure, say N.



menu "SLAB allocator options"



choice

	prompt "Choose SLAB allocator"

	default SLUB
@@ -90,6 +275,19 @@ config SLAB_FREELIST_HARDENED 
	  sanity-checking than others. This option is most effective with

	  CONFIG_SLUB.



config SLUB_CPU_PARTIAL

	default y

	depends on SLUB && SMP

	bool "SLUB per cpu partial cache"

	help

	  Per cpu partial caches accelerate objects allocation and freeing

	  that is local to a processor at the price of more indeterminism

	  in the latency of the free. On overflow these caches will be cleared

	  which requires the taking of locks that may cause latency spikes.

	  Typically one would choose no for a realtime system.



endmenu # SLAB allocator options



config SHUFFLE_PAGE_ALLOCATOR

	bool "Page allocator randomization"

	default SLAB_FREELIST_RANDOM && ACPI_NUMA
@@ -114,17 +312,6 @@ config SHUFFLE_PAGE_ALLOCATOR 


	  Say Y if unsure.



config SLUB_CPU_PARTIAL

	default y

	depends on SLUB && SMP

	bool "SLUB per cpu partial cache"

	help

	  Per cpu partial caches accelerate objects allocation and freeing

	  that is local to a processor at the price of more indeterminism

	  in the latency of the free. On overflow these caches will be cleared

	  which requires the taking of locks that may cause latency spikes.

	  Typically one would choose no for a realtime system.



config SELECT_MEMORY_MODEL

	def_bool y

	depends on ARCH_SELECT_MEMORY_MODEL
@@ -249,15 +436,20 @@ config HAVE_BOOTMEM_INFO_NODE 
config ARCH_ENABLE_MEMORY_HOTPLUG

	bool



config ARCH_ENABLE_MEMORY_HOTREMOVE

	bool



# eventually, we can have this option just 'select SPARSEMEM'

config MEMORY_HOTPLUG

	bool "Allow for memory hot-add"

menuconfig MEMORY_HOTPLUG

	bool "Memory hotplug"

	select MEMORY_ISOLATION

	depends on SPARSEMEM

	depends on ARCH_ENABLE_MEMORY_HOTPLUG

	depends on 64BIT

	select NUMA_KEEP_MEMINFO if NUMA



if MEMORY_HOTPLUG



config MEMORY_HOTPLUG_DEFAULT_ONLINE

	bool "Online the newly added memory blocks by default"

	depends on MEMORY_HOTPLUG
@@ -273,9 +465,6 @@ config MEMORY_HOTPLUG_DEFAULT_ONLINE 
	  Say N here if you want the default policy to keep all hot-plugged

	  memory blocks in 'offline' state.



config ARCH_ENABLE_MEMORY_HOTREMOVE

	bool



config MEMORY_HOTREMOVE

	bool "Allow for memory hot remove"

	select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64)
@@ -287,6 +476,8 @@ config MHP_MEMMAP_ON_MEMORY 
	depends on MEMORY_HOTPLUG && SPARSEMEM_VMEMMAP

	depends on ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE



endif # MEMORY_HOTPLUG



# Heavily threaded applications may benefit from splitting the mm-wide

# page_table_lock, so that faults on different parts of the user address

# space can be handled with less contention: split it at this NR_CPUS.
@@ -501,7 +692,13 @@ config NOMMU_INITIAL_TRIM_EXCESS 


	  See Documentation/admin-guide/mm/nommu-mmap.rst for more information.



config TRANSPARENT_HUGEPAGE

config ARCH_WANT_GENERAL_HUGETLB

	bool



config ARCH_WANTS_THP_SWAP

	def_bool n



menuconfig TRANSPARENT_HUGEPAGE

	bool "Transparent Hugepage Support"

	depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE && !PREEMPT_RT

	select COMPACTION
@@ -516,6 +713,8 @@ config TRANSPARENT_HUGEPAGE 


	  If memory constrained on embedded, you may want to say N.



if TRANSPARENT_HUGEPAGE



choice

	prompt "Transparent Hugepage Support sysfs defaults"

	depends on TRANSPARENT_HUGEPAGE
@@ -540,12 +739,6 @@ choice 
	  benefit.

endchoice



config ARCH_WANT_GENERAL_HUGETLB

	bool



config ARCH_WANTS_THP_SWAP

	def_bool n



config THP_SWAP

	def_bool y

	depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP
@@ -556,6 +749,19 @@ config THP_SWAP 


	  For selection by architectures with reasonable THP sizes.



config READ_ONLY_THP_FOR_FS

	bool "Read-only THP for filesystems (EXPERIMENTAL)"

	depends on TRANSPARENT_HUGEPAGE && SHMEM



	help

	  Allow khugepaged to put read-only file-backed pages in THP.



	  This is marked experimental because it is a new feature. Write

	  support of file THPs will be developed in the next few release

	  cycles.



endif # TRANSPARENT_HUGEPAGE



#

# UP and nommu archs use km based percpu allocator

#
@@ -640,188 +846,6 @@ config MEM_SOFT_DIRTY 


	  See Documentation/admin-guide/mm/soft-dirty.rst for more details.



config ZSWAP

	bool "Compressed cache for swap pages (EXPERIMENTAL)"

	depends on SWAP && CRYPTO=y

	select FRONTSWAP

	select ZPOOL

	help

	  A lightweight compressed cache for swap pages.  It takes

	  pages that are in the process of being swapped out and attempts to

	  compress them into a dynamically allocated RAM-based memory pool.

	  This can result in a significant I/O reduction on swap device and,

	  in the case where decompressing from RAM is faster that swap device

	  reads, can also improve workload performance.



	  This is marked experimental because it is a new feature (as of

	  v3.11) that interacts heavily with memory reclaim.  While these

	  interactions don't cause any known issues on simple memory setups,

	  they have not be fully explored on the large set of potential

	  configurations and workloads that exist.



choice

	prompt "Compressed cache for swap pages default compressor"

	depends on ZSWAP

	default ZSWAP_COMPRESSOR_DEFAULT_LZO

	help

	  Selects the default compression algorithm for the compressed cache

	  for swap pages.



	  For an overview what kind of performance can be expected from

	  a particular compression algorithm please refer to the benchmarks

	  available at the following LWN page:

	  https://lwn.net/Articles/751795/



	  If in doubt, select 'LZO'.



	  The selection made here can be overridden by using the kernel

	  command line 'zswap.compressor=' option.



config ZSWAP_COMPRESSOR_DEFAULT_DEFLATE

	bool "Deflate"

	select CRYPTO_DEFLATE

	help

	  Use the Deflate algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_LZO

	bool "LZO"

	select CRYPTO_LZO

	help

	  Use the LZO algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_842

	bool "842"

	select CRYPTO_842

	help

	  Use the 842 algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_LZ4

	bool "LZ4"

	select CRYPTO_LZ4

	help

	  Use the LZ4 algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_LZ4HC

	bool "LZ4HC"

	select CRYPTO_LZ4HC

	help

	  Use the LZ4HC algorithm as the default compression algorithm.



config ZSWAP_COMPRESSOR_DEFAULT_ZSTD

	bool "zstd"

	select CRYPTO_ZSTD

	help

	  Use the zstd algorithm as the default compression algorithm.

endchoice



config ZSWAP_COMPRESSOR_DEFAULT

       string

       depends on ZSWAP

       default "deflate" if ZSWAP_COMPRESSOR_DEFAULT_DEFLATE

       default "lzo" if ZSWAP_COMPRESSOR_DEFAULT_LZO

       default "842" if ZSWAP_COMPRESSOR_DEFAULT_842

       default "lz4" if ZSWAP_COMPRESSOR_DEFAULT_LZ4

       default "lz4hc" if ZSWAP_COMPRESSOR_DEFAULT_LZ4HC

       default "zstd" if ZSWAP_COMPRESSOR_DEFAULT_ZSTD

       default ""



choice

	prompt "Compressed cache for swap pages default allocator"

	depends on ZSWAP

	default ZSWAP_ZPOOL_DEFAULT_ZBUD

	help

	  Selects the default allocator for the compressed cache for

	  swap pages.

	  The default is 'zbud' for compatibility, however please do

	  read the description of each of the allocators below before

	  making a right choice.



	  The selection made here can be overridden by using the kernel

	  command line 'zswap.zpool=' option.



config ZSWAP_ZPOOL_DEFAULT_ZBUD

	bool "zbud"

	select ZBUD

	help

	  Use the zbud allocator as the default allocator.



config ZSWAP_ZPOOL_DEFAULT_Z3FOLD

	bool "z3fold"

	select Z3FOLD

	help

	  Use the z3fold allocator as the default allocator.



config ZSWAP_ZPOOL_DEFAULT_ZSMALLOC

	bool "zsmalloc"

	select ZSMALLOC

	help

	  Use the zsmalloc allocator as the default allocator.

endchoice



config ZSWAP_ZPOOL_DEFAULT

       string

       depends on ZSWAP

       default "zbud" if ZSWAP_ZPOOL_DEFAULT_ZBUD

       default "z3fold" if ZSWAP_ZPOOL_DEFAULT_Z3FOLD

       default "zsmalloc" if ZSWAP_ZPOOL_DEFAULT_ZSMALLOC

       default ""



config ZSWAP_DEFAULT_ON

	bool "Enable the compressed cache for swap pages by default"

	depends on ZSWAP

	help

	  If selected, the compressed cache for swap pages will be enabled

	  at boot, otherwise it will be disabled.



	  The selection made here can be overridden by using the kernel

	  command line 'zswap.enabled=' option.



config ZPOOL

	tristate "Common API for compressed memory storage"

	help

	  Compressed memory storage API.  This allows using either zbud or

	  zsmalloc.



config ZBUD

	tristate "Low (Up to 2x) density storage for compressed pages"

	depends on ZPOOL

	help

	  A special purpose allocator for storing compressed pages.

	  It is designed to store up to two compressed pages per physical

	  page.  While this design limits storage density, it has simple and

	  deterministic reclaim properties that make it preferable to a higher

	  density approach when reclaim will be used.



config Z3FOLD

	tristate "Up to 3x density storage for compressed pages"

	depends on ZPOOL

	help

	  A special purpose allocator for storing compressed pages.

	  It is designed to store up to three compressed pages per physical

	  page. It is a ZBUD derivative so the simplicity and determinism are

	  still there.



config ZSMALLOC

	tristate "Memory allocator for compressed pages"

	depends on MMU

	help

	  zsmalloc is a slab-based memory allocator designed to store

	  compressed RAM pages.  zsmalloc uses virtual memory mapping

	  in order to reduce fragmentation.  However, this results in a

	  non-standard allocator interface where a handle, not a pointer, is

	  returned by an alloc().  This handle must be mapped in order to

	  access the allocated space.



config ZSMALLOC_STAT

	bool "Export zsmalloc statistics"

	depends on ZSMALLOC

	select DEBUG_FS

	help

	  This option enables code in the zsmalloc to collect various

	  statistics about what's happening in zsmalloc and exports that

	  information to userspace via debugfs.

	  If unsure, say N.



config GENERIC_EARLY_IOREMAP

	bool
@@ -978,17 +1002,6 @@ comment "GUP_TEST needs to have DEBUG_FS enabled" 
config GUP_GET_PTE_LOW_HIGH

	bool



config READ_ONLY_THP_FOR_FS

	bool "Read-only THP for filesystems (EXPERIMENTAL)"

	depends on TRANSPARENT_HUGEPAGE && SHMEM



	help

	  Allow khugepaged to put read-only file-backed pages in THP.



	  This is marked experimental because it is a new feature. Write

	  support of file THPs will be developed in the next few release

	  cycles.



config ARCH_HAS_PTE_SPECIAL

	bool