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
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
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
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
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
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)
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.
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
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
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
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
#
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
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
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