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 section a bit more organized and easier to navigate. Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> --- mm/Kconfig | 428 +++++++++++++++++++++++++++-------------------------- 1 file changed, 222 insertions(+), 206 deletions(-) diff --git a/mm/Kconfig b/mm/Kconfig index 894858536e7f..dbceaa2a04a4 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -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 +19,192 @@ config SWAP used to provide more virtual memory than the actual RAM present in your computer. If unsure say Y. +if SWAP + +config ZSWAP + bool "Compressed cache for swap pages (EXPERIMENTAL)" + depends on FRONTSWAP && CRYPTO=y + 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" + 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. + +endif # SWAP + +menu "SLAB allocator options" + choice prompt "Choose SLAB allocator" default SLUB @@ -87,6 +273,19 @@ 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 @@ -111,17 +310,6 @@ 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 @@ -272,14 +460,16 @@ config ARCH_ENABLE_MEMORY_HOTPLUG 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 || X86_64_ACPI_NUMA depends on ARCH_ENABLE_MEMORY_HOTPLUG depends on 64BIT || BROKEN select NUMA_KEEP_MEMINFO if NUMA +if MEMORY_HOTPLUG + config MEMORY_HOTPLUG_SPARSE def_bool y depends on SPARSEMEM && MEMORY_HOTPLUG @@ -313,6 +503,8 @@ 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. @@ -521,7 +713,7 @@ config NOMMU_INITIAL_TRIM_EXCESS See Documentation/admin-guide/mm/nommu-mmap.rst for more information. -config TRANSPARENT_HUGEPAGE +menuconfig TRANSPARENT_HUGEPAGE bool "Transparent Hugepage Support" depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE select COMPACTION @@ -536,6 +728,8 @@ 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 @@ -573,6 +767,19 @@ 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 # @@ -680,186 +887,6 @@ 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 FRONTSWAP && CRYPTO=y - 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" - 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 @@ -988,17 +1015,6 @@ 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 -- 2.32.0
