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mm/Kconfig
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# SPDX-License-Identifier: GPL-2.0-only |
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menu "Memory Management options" |
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config SELECT_MEMORY_MODEL def_bool y |
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depends on ARCH_SELECT_MEMORY_MODEL |
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choice prompt "Memory model" |
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depends on SELECT_MEMORY_MODEL default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT |
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default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT |
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default FLATMEM_MANUAL |
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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. |
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config FLATMEM_MANUAL |
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bool "Flat Memory" |
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depends on !(ARCH_DISCONTIGMEM_ENABLE || ARCH_SPARSEMEM_ENABLE) || ARCH_FLATMEM_ENABLE |
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help |
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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" |
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If unsure, choose this option (Flat Memory) over any other. |
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config DISCONTIGMEM_MANUAL |
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bool "Discontiguous Memory" |
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depends on ARCH_DISCONTIGMEM_ENABLE help |
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This option provides enhanced support for discontiguous memory systems, over FLATMEM. These systems have holes in their physical address spaces, and this option provides |
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more efficient handling of these holes. |
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Although "Discontiguous Memory" is still used by several architectures, it is considered deprecated in favor of "Sparse Memory". |
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If unsure, choose "Sparse Memory" over this option. |
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config SPARSEMEM_MANUAL bool "Sparse Memory" depends on ARCH_SPARSEMEM_ENABLE help This will be the only option for some systems, including |
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memory hot-plug systems. This is normal. |
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This option provides efficient support for systems with holes is their physical address space and allows memory hot-plug and hot-remove. |
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If unsure, choose "Flat Memory" over this option. |
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endchoice |
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config DISCONTIGMEM def_bool y depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL |
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config SPARSEMEM def_bool y |
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depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL |
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config FLATMEM def_bool y |
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depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL config FLAT_NODE_MEM_MAP def_bool y depends on !SPARSEMEM |
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# # Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's # to represent different areas of memory. This variable allows # those dependencies to exist individually. # config NEED_MULTIPLE_NODES def_bool y depends on DISCONTIGMEM || NUMA |
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config HAVE_MEMORY_PRESENT def_bool y |
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depends on ARCH_HAVE_MEMORY_PRESENT || SPARSEMEM |
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# |
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# SPARSEMEM_EXTREME (which is the default) does some bootmem |
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# allocations when memory_present() is called. If this cannot |
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# be done on your architecture, select this option. However, # statically allocating the mem_section[] array can potentially # consume vast quantities of .bss, so be careful. # # This option will also potentially produce smaller runtime code # with gcc 3.4 and later. # config SPARSEMEM_STATIC |
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bool |
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# |
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# Architecture platforms which require a two level mem_section in SPARSEMEM |
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# must select this option. This is usually for architecture platforms with # an extremely sparse physical address space. # |
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config SPARSEMEM_EXTREME def_bool y depends on SPARSEMEM && !SPARSEMEM_STATIC |
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config SPARSEMEM_VMEMMAP_ENABLE |
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bool |
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config SPARSEMEM_VMEMMAP |
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bool "Sparse Memory virtual memmap" depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE default y help SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise pfn_to_page and page_to_pfn operations. This is the most efficient option when sufficient kernel resources are available. |
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config HAVE_MEMBLOCK_NODE_MAP |
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bool |
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config HAVE_MEMBLOCK_PHYS_MAP |
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bool |
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config HAVE_FAST_GUP |
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depends on MMU |
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bool |
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config ARCH_KEEP_MEMBLOCK |
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bool |
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config MEMORY_ISOLATION |
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bool |
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# # Only be set on architectures that have completely implemented memory hotplug # feature. If you are not sure, don't touch it. # config HAVE_BOOTMEM_INFO_NODE def_bool n |
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# eventually, we can have this option just 'select SPARSEMEM' config MEMORY_HOTPLUG bool "Allow for memory hot-add" |
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depends on SPARSEMEM || X86_64_ACPI_NUMA |
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depends on ARCH_ENABLE_MEMORY_HOTPLUG |
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config MEMORY_HOTPLUG_SPARSE def_bool y depends on SPARSEMEM && MEMORY_HOTPLUG |
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config MEMORY_HOTPLUG_DEFAULT_ONLINE bool "Online the newly added memory blocks by default" |
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depends on MEMORY_HOTPLUG help This option sets the default policy setting for memory hotplug onlining policy (/sys/devices/system/memory/auto_online_blocks) which determines what happens to newly added memory regions. Policy setting can always be changed at runtime. |
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See Documentation/admin-guide/mm/memory-hotplug.rst for more information. |
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Say Y here if you want all hot-plugged memory blocks to appear in 'online' state by default. Say N here if you want the default policy to keep all hot-plugged memory blocks in 'offline' state. |
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config MEMORY_HOTREMOVE bool "Allow for memory hot remove" |
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select MEMORY_ISOLATION |
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select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64) |
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depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE depends on MIGRATION |
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# 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. # Default to 4 for wider testing, though 8 might be more appropriate. # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock. |
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# PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes. |
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# DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC spinlock_t also enlarge struct page. |
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# config SPLIT_PTLOCK_CPUS int |
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default "999999" if !MMU |
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default "999999" if ARM && !CPU_CACHE_VIPT default "999999" if PARISC && !PA20 |
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default "4" |
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config ARCH_ENABLE_SPLIT_PMD_PTLOCK |
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bool |
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# |
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# support for memory balloon config MEMORY_BALLOON |
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bool |
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# |
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# support for memory balloon compaction config BALLOON_COMPACTION bool "Allow for balloon memory compaction/migration" def_bool y |
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depends on COMPACTION && MEMORY_BALLOON |
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help Memory fragmentation introduced by ballooning might reduce significantly the number of 2MB contiguous memory blocks that can be used within a guest, thus imposing performance penalties associated with the reduced number of transparent huge pages that could be used by the guest workload. Allowing the compaction & migration for memory pages enlisted as being part of memory balloon devices avoids the scenario aforementioned and helps improving memory defragmentation. # |
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# support for memory compaction config COMPACTION bool "Allow for memory compaction" |
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def_bool y |
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select MIGRATION |
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depends on MMU |
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help |
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Compaction is the only memory management component to form high order (larger physically contiguous) memory blocks reliably. The page allocator relies on compaction heavily and the lack of the feature can lead to unexpected OOM killer invocations for high order memory requests. You shouldn't disable this option unless there really is a strong reason for it and then we would be really interested to hear about that at linux-mm@kvack.org. |
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# |
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# support for page migration # config MIGRATION |
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bool "Page migration" |
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def_bool y |
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depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU |
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help Allows the migration of the physical location of pages of processes |
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while the virtual addresses are not changed. This is useful in two situations. The first is on NUMA systems to put pages nearer to the processors accessing. The second is when allocating huge pages as migration can relocate pages to satisfy a huge page allocation instead of reclaiming. |
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config ARCH_ENABLE_HUGEPAGE_MIGRATION |
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bool |
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config ARCH_ENABLE_THP_MIGRATION bool |
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config CONTIG_ALLOC def_bool (MEMORY_ISOLATION && COMPACTION) || CMA |
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config PHYS_ADDR_T_64BIT |
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def_bool 64BIT |
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config BOUNCE |
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bool "Enable bounce buffers" default y |
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depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM) |
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help Enable bounce buffers for devices that cannot access the full range of memory available to the CPU. Enabled by default when ZONE_DMA or HIGHMEM is selected, but you may say n to override this. |
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config VIRT_TO_BUS |
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bool help An architecture should select this if it implements the deprecated interface virt_to_bus(). All new architectures should probably not select this. |
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config MMU_NOTIFIER bool |
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select SRCU |
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config KSM bool "Enable KSM for page merging" depends on MMU |
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select XXHASH |
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help Enable Kernel Samepage Merging: KSM periodically scans those areas of an application's address space that an app has advised may be mergeable. When it finds pages of identical content, it replaces |
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the many instances by a single page with that content, so |
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saving memory until one or another app needs to modify the content. Recommended for use with KVM, or with other duplicative applications. |
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See Documentation/vm/ksm.rst for more information: KSM is inactive |
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until a program has madvised that an area is MADV_MERGEABLE, and root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set). |
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config DEFAULT_MMAP_MIN_ADDR int "Low address space to protect from user allocation" |
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depends on MMU |
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default 4096 help This is the portion of low virtual memory which should be protected from userspace allocation. Keeping a user from writing to low pages can help reduce the impact of kernel NULL pointer bugs. For most ia64, ppc64 and x86 users with lots of address space a value of 65536 is reasonable and should cause no problems. On arm and other archs it should not be higher than 32768. |
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Programs which use vm86 functionality or have some need to map this low address space will need CAP_SYS_RAWIO or disable this protection by setting the value to 0. |
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This value can be changed after boot using the /proc/sys/vm/mmap_min_addr tunable. |
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config ARCH_SUPPORTS_MEMORY_FAILURE bool |
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config MEMORY_FAILURE depends on MMU |
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depends on ARCH_SUPPORTS_MEMORY_FAILURE |
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bool "Enable recovery from hardware memory errors" |
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select MEMORY_ISOLATION |
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select RAS |
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help Enables code to recover from some memory failures on systems with MCA recovery. This allows a system to continue running even when some of its memory has uncorrected errors. This requires special hardware support and typically ECC memory. |
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config HWPOISON_INJECT |
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tristate "HWPoison pages injector" |
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depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS |
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select PROC_PAGE_MONITOR |
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config NOMMU_INITIAL_TRIM_EXCESS int "Turn on mmap() excess space trimming before booting" depends on !MMU default 1 help The NOMMU mmap() frequently needs to allocate large contiguous chunks of memory on which to store mappings, but it can only ask the system allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently more than it requires. To deal with this, mmap() is able to trim off the excess and return it to the allocator. If trimming is enabled, the excess is trimmed off and returned to the system allocator, which can cause extra fragmentation, particularly if there are a lot of transient processes. If trimming is disabled, the excess is kept, but not used, which for long-term mappings means that the space is wasted. Trimming can be dynamically controlled through a sysctl option (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of excess pages there must be before trimming should occur, or zero if no trimming is to occur. This option specifies the initial value of this option. The default of 1 says that all excess pages should be trimmed. See Documentation/nommu-mmap.txt for more information. |
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config TRANSPARENT_HUGEPAGE |
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bool "Transparent Hugepage Support" |
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depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE |
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select COMPACTION |
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select XARRAY_MULTI |
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help Transparent Hugepages allows the kernel to use huge pages and huge tlb transparently to the applications whenever possible. This feature can improve computing performance to certain applications by speeding up page faults during memory allocation, by reducing the number of tlb misses and by speeding up the pagetable walking. If memory constrained on embedded, you may want to say N. |
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choice prompt "Transparent Hugepage Support sysfs defaults" depends on TRANSPARENT_HUGEPAGE default TRANSPARENT_HUGEPAGE_ALWAYS help Selects the sysfs defaults for Transparent Hugepage Support. config TRANSPARENT_HUGEPAGE_ALWAYS bool "always" help Enabling Transparent Hugepage always, can increase the memory footprint of applications without a guaranteed benefit but it will work automatically for all applications. config TRANSPARENT_HUGEPAGE_MADVISE bool "madvise" help Enabling Transparent Hugepage madvise, will only provide a performance improvement benefit to the applications using madvise(MADV_HUGEPAGE) but it won't risk to increase the memory footprint of applications without a guaranteed benefit. endchoice |
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config ARCH_WANTS_THP_SWAP def_bool n config THP_SWAP def_bool y |
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depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP |
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help Swap transparent huge pages in one piece, without splitting. |
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XXX: For now, swap cluster backing transparent huge page will be split after swapout. |
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For selection by architectures with reasonable THP sizes. |
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config TRANSPARENT_HUGE_PAGECACHE def_bool y |
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depends on TRANSPARENT_HUGEPAGE |
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# |
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# UP and nommu archs use km based percpu allocator # config NEED_PER_CPU_KM depends on !SMP bool default y |
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config CLEANCACHE bool "Enable cleancache driver to cache clean pages if tmem is present" |
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help Cleancache can be thought of as a page-granularity victim cache for clean pages that the kernel's pageframe replacement algorithm (PFRA) would like to keep around, but can't since there isn't enough memory. So when the PFRA "evicts" a page, it first attempts to use |
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cleancache code to put the data contained in that page into |
077b1f83a mm: cleancache co... |
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"transcendent memory", memory that is not directly accessible or addressable by the kernel and is of unknown and possibly time-varying size. And when a cleancache-enabled filesystem wishes to access a page in a file on disk, it first checks cleancache to see if it already contains it; if it does, the page is copied into the kernel and a disk access is avoided. When a transcendent memory driver is available (such as zcache or Xen transcendent memory), a significant I/O reduction may be achieved. When none is available, all cleancache calls are reduced to a single pointer-compare-against-NULL resulting in a negligible performance hit. If unsure, say Y to enable cleancache |
27c6aec21 mm: frontswap: co... |
440 441 442 443 |
config FRONTSWAP bool "Enable frontswap to cache swap pages if tmem is present" depends on SWAP |
27c6aec21 mm: frontswap: co... |
444 445 446 447 448 449 450 451 452 453 454 455 |
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 "transcendent memory", memory that is not directly accessible or addressable by the kernel and is of unknown and possibly time-varying size. When space in transcendent memory is available, a significant swap I/O reduction may be achieved. When none is available, all frontswap calls are reduced to a single pointer- compare-against-NULL resulting in a negligible performance hit and swap data is stored as normal on the matching swap device. If unsure, say Y to enable frontswap. |
f825c736e mm/cma: Move dma ... |
456 457 458 |
config CMA bool "Contiguous Memory Allocator" |
aca52c398 mm: remove CONFIG... |
459 |
depends on MMU |
f825c736e mm/cma: Move dma ... |
460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 |
select MIGRATION select MEMORY_ISOLATION help This enables the Contiguous Memory Allocator which allows other subsystems to allocate big physically-contiguous blocks of memory. CMA reserves a region of memory and allows only movable pages to be allocated from it. This way, the kernel can use the memory for pagecache and when a subsystem requests for contiguous area, the allocated pages are migrated away to serve the contiguous request. If unsure, say "n". config CMA_DEBUG bool "CMA debug messages (DEVELOPMENT)" depends on DEBUG_KERNEL && CMA help Turns on debug messages in CMA. This produces KERN_DEBUG messages for every CMA call as well as various messages while processing calls such as dma_alloc_from_contiguous(). This option does not affect warning and error messages. |
bf550fc93 Merge remote-trac... |
480 |
|
28b24c1fc mm: cma: debugfs ... |
481 482 483 484 485 |
config CMA_DEBUGFS bool "CMA debugfs interface" depends on CMA && DEBUG_FS help Turns on the DebugFS interface for CMA. |
a254129e8 CMA: generalize C... |
486 487 488 489 490 491 492 493 494 495 |
config CMA_AREAS int "Maximum count of the CMA areas" depends on CMA default 7 help CMA allows to create CMA areas for particular purpose, mainly, used as device private area. This parameter sets the maximum number of CMA area in the system. If unsure, leave the default value "7". |
af8d417a0 mm/zpool: impleme... |
496 497 498 499 |
config MEM_SOFT_DIRTY bool "Track memory changes" depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS select PROC_PAGE_MONITOR |
4e2e2770b zbud: add to mm/ |
500 |
help |
af8d417a0 mm/zpool: impleme... |
501 502 503 504 |
This option enables memory changes tracking by introducing a soft-dirty bit on pte-s. This bit it set when someone writes into a page just as regular dirty bit, but unlike the latter it can be cleared by hands. |
1ad1335dc docs/admin-guide/... |
505 |
See Documentation/admin-guide/mm/soft-dirty.rst for more details. |
4e2e2770b zbud: add to mm/ |
506 |
|
2b2811178 zswap: add to mm/ |
507 508 509 510 |
config ZSWAP bool "Compressed cache for swap pages (EXPERIMENTAL)" depends on FRONTSWAP && CRYPTO=y select CRYPTO_LZO |
12d79d64b mm/zpool: update ... |
511 |
select ZPOOL |
2b2811178 zswap: add to mm/ |
512 513 514 515 516 517 518 519 520 521 522 523 524 |
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. |
af8d417a0 mm/zpool: impleme... |
525 526 |
config ZPOOL tristate "Common API for compressed memory storage" |
0f8975ec4 mm: soft-dirty bi... |
527 |
help |
af8d417a0 mm/zpool: impleme... |
528 529 |
Compressed memory storage API. This allows using either zbud or zsmalloc. |
0f8975ec4 mm: soft-dirty bi... |
530 |
|
af8d417a0 mm/zpool: impleme... |
531 |
config ZBUD |
9a001fc19 z3fold: the 3-fol... |
532 |
tristate "Low (Up to 2x) density storage for compressed pages" |
af8d417a0 mm/zpool: impleme... |
533 534 535 536 537 538 |
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. |
bcf1647d0 zsmalloc: move it... |
539 |
|
9a001fc19 z3fold: the 3-fol... |
540 541 542 |
config Z3FOLD tristate "Up to 3x density storage for compressed pages" depends on ZPOOL |
9a001fc19 z3fold: the 3-fol... |
543 544 545 546 547 |
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. |
bcf1647d0 zsmalloc: move it... |
548 |
config ZSMALLOC |
d867f203b mm/zsmalloc: make... |
549 |
tristate "Memory allocator for compressed pages" |
bcf1647d0 zsmalloc: move it... |
550 |
depends on MMU |
bcf1647d0 zsmalloc: move it... |
551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 |
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 PGTABLE_MAPPING bool "Use page table mapping to access object in zsmalloc" depends on ZSMALLOC help By default, zsmalloc uses a copy-based object mapping method to access allocations that span two pages. However, if a particular architecture (ex, ARM) performs VM mapping faster than copying, then you should select this. This causes zsmalloc to use page table mapping rather than copying for object mapping. |
2216ee853 mm/Kconfig: fix U... |
568 569 |
You can check speed with zsmalloc benchmark: https://github.com/spartacus06/zsmapbench |
9e5c33d7a mm: create generi... |
570 |
|
0f050d997 mm/zsmalloc: add ... |
571 572 573 574 575 576 577 578 579 |
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 whats happening in zsmalloc and exports that information to userspace via debugfs. If unsure, say N. |
9e5c33d7a mm: create generi... |
580 581 |
config GENERIC_EARLY_IOREMAP bool |
042d27acb parisc,metag: Do ... |
582 583 584 585 |
config MAX_STACK_SIZE_MB int "Maximum user stack size for 32-bit processes (MB)" default 80 |
042d27acb parisc,metag: Do ... |
586 587 588 589 590 |
range 8 2048 depends on STACK_GROWSUP && (!64BIT || COMPAT) help This is the maximum stack size in Megabytes in the VM layout of 32-bit user processes when the stack grows upwards (currently only on parisc |
5f171577b Drop a bunch of m... |
591 592 593 |
arch). The stack will be located at the highest memory address minus the given value, unless the RLIMIT_STACK hard limit is changed to a smaller value in which case that is used. |
042d27acb parisc,metag: Do ... |
594 595 |
A sane initial value is 80 MB. |
3a80a7fa7 mm: meminit: init... |
596 |
|
3a80a7fa7 mm: meminit: init... |
597 |
config DEFERRED_STRUCT_PAGE_INIT |
1ce221036 mm/Kconfig: corre... |
598 |
bool "Defer initialisation of struct pages to kthreads" |
d39f8fb4b mm: make DEFERRED... |
599 |
depends on SPARSEMEM |
ab1e8d896 mm: don't allow d... |
600 |
depends on !NEED_PER_CPU_KM |
889c695d4 mm: disable defer... |
601 |
depends on 64BIT |
3a80a7fa7 mm: meminit: init... |
602 603 604 605 606 |
help Ordinarily all struct pages are initialised during early boot in a single thread. On very large machines this can take a considerable amount of time. If this option is set, large machines will bring up a subset of memmap at boot and then initialise the rest in parallel |
1ce221036 mm/Kconfig: corre... |
607 608 609 610 |
by starting one-off "pgdatinitX" kernel thread for each node X. This has a potential performance impact on processes running early in the lifetime of the system until these kthreads finish the initialisation. |
033fbae98 mm: ZONE_DEVICE f... |
611 |
|
33c3fc71c mm: introduce idl... |
612 613 614 615 616 617 618 619 620 |
config IDLE_PAGE_TRACKING bool "Enable idle page tracking" depends on SYSFS && MMU select PAGE_EXTENSION if !64BIT help This feature allows to estimate the amount of user pages that have not been touched during a given period of time. This information can be useful to tune memory cgroup limits and/or for job placement within a compute cluster. |
1ad1335dc docs/admin-guide/... |
621 622 |
See Documentation/admin-guide/mm/idle_page_tracking.rst for more details. |
33c3fc71c mm: introduce idl... |
623 |
|
175967318 mm: introduce ARC... |
624 |
config ARCH_HAS_PTE_DEVMAP |
65f7d0497 mm, x86: Add ARCH... |
625 |
bool |
033fbae98 mm: ZONE_DEVICE f... |
626 |
config ZONE_DEVICE |
5042db43c mm/ZONE_DEVICE: n... |
627 |
bool "Device memory (pmem, HMM, etc...) hotplug support" |
033fbae98 mm: ZONE_DEVICE f... |
628 629 |
depends on MEMORY_HOTPLUG depends on MEMORY_HOTREMOVE |
99490f16f mm: ZONE_DEVICE d... |
630 |
depends on SPARSEMEM_VMEMMAP |
175967318 mm: introduce ARC... |
631 |
depends on ARCH_HAS_PTE_DEVMAP |
3a08cd52c radix tree: Remov... |
632 |
select XARRAY_MULTI |
033fbae98 mm: ZONE_DEVICE f... |
633 634 635 636 637 638 639 640 641 |
help Device memory hotplug support allows for establishing pmem, or other device driver discovered memory regions, in the memmap. This allows pfn_to_page() lookups of otherwise "device-physical" addresses which is needed for using a DAX mapping in an O_DIRECT operation, among other things. If FS_DAX is enabled, then say Y. |
06a660ada Merge tag 'media/... |
642 |
|
e76384884 mm: introduce MEM... |
643 644 |
config DEV_PAGEMAP_OPS bool |
9c240a7bb mm/hmm: make HMM_... |
645 646 647 648 |
# # Helpers to mirror range of the CPU page tables of a process into device page # tables. # |
c0b124054 mm/hmm/mirror: mi... |
649 |
config HMM_MIRROR |
9c240a7bb mm/hmm: make HMM_... |
650 |
bool |
f442c283e mm/hmm: allow HMM... |
651 |
depends on MMU |
9c240a7bb mm/hmm: make HMM_... |
652 |
depends on MMU_NOTIFIER |
c0b124054 mm/hmm/mirror: mi... |
653 |
|
5042db43c mm/ZONE_DEVICE: n... |
654 655 |
config DEVICE_PRIVATE bool "Unaddressable device memory (GPU memory, ...)" |
7328d9cc1 mm: sort out the ... |
656 |
depends on ZONE_DEVICE |
e76384884 mm: introduce MEM... |
657 |
select DEV_PAGEMAP_OPS |
5042db43c mm/ZONE_DEVICE: n... |
658 659 660 661 662 |
help Allows creation of struct pages to represent unaddressable device memory; i.e., memory that is only accessible from the device (or group of devices). You likely also want to select HMM_MIRROR. |
8025e5ddf [media] mm: Provi... |
663 664 |
config FRAME_VECTOR bool |
63c17fb8e mm/core, x86/mm/p... |
665 666 667 |
config ARCH_USES_HIGH_VMA_FLAGS bool |
66d375709 mm/core, x86/mm/p... |
668 669 |
config ARCH_HAS_PKEYS bool |
30a5b5367 percpu: expose st... |
670 671 672 |
config PERCPU_STATS bool "Collect percpu memory statistics" |
30a5b5367 percpu: expose st... |
673 674 675 676 |
help This feature collects and exposes statistics via debugfs. The information includes global and per chunk statistics, which can be used to help understand percpu memory usage. |
64c349f4a mm: add infrastru... |
677 678 679 |
config GUP_BENCHMARK bool "Enable infrastructure for get_user_pages_fast() benchmarking" |
64c349f4a mm: add infrastru... |
680 681 682 683 684 |
help Provides /sys/kernel/debug/gup_benchmark that helps with testing performance of get_user_pages_fast(). See tools/testing/selftests/vm/gup_benchmark.c |
3010a5ea6 mm: introduce ARC... |
685 |
|
39656e83d mm: lift the x86_... |
686 687 |
config GUP_GET_PTE_LOW_HIGH bool |
99cb0dbd4 mm,thp: add read-... |
688 689 690 691 692 693 694 695 696 697 |
config READ_ONLY_THP_FOR_FS bool "Read-only THP for filesystems (EXPERIMENTAL)" depends on TRANSPARENT_HUGE_PAGECACHE && 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. |
3010a5ea6 mm: introduce ARC... |
698 699 |
config ARCH_HAS_PTE_SPECIAL bool |
59e0b520c kconfig: add a Me... |
700 |
|
cbd34da7d mm: move the powe... |
701 702 703 704 705 706 707 708 709 |
# # Some architectures require a special hugepage directory format that is # required to support multiple hugepage sizes. For example a4fe3ce76 # "powerpc/mm: Allow more flexible layouts for hugepage pagetables" # introduced it on powerpc. This allows for a more flexible hugepage # pagetable layouts. # config ARCH_HAS_HUGEPD bool |
59e0b520c kconfig: add a Me... |
710 |
endmenu |