736 lines
24 KiB
Text
736 lines
24 KiB
Text
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config SELECT_MEMORY_MODEL
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def_bool y
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depends on ARCH_SELECT_MEMORY_MODEL
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choice
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prompt "Memory model"
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depends on SELECT_MEMORY_MODEL
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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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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 allows you to change some of the ways that
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Linux manages its memory internally. Most users will
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only have one option here: FLATMEM. This is normal
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and a correct option.
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Some users of more advanced features like NUMA and
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memory hotplug may have different options here.
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DISCONTIGMEM is a more mature, better tested system,
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but is incompatible with memory hotplug and may suffer
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decreased performance over SPARSEMEM. If unsure between
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"Sparse Memory" and "Discontiguous Memory", choose
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"Discontiguous 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
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help
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This option provides enhanced support for discontiguous
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memory systems, over FLATMEM. These systems have holes
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in their physical address spaces, and this option provides
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more efficient handling of these holes. However, the vast
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majority of hardware has quite flat address spaces, and
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can have degraded performance from the extra overhead that
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this option imposes.
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Many NUMA configurations will have this as the only option.
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If unsure, choose "Flat Memory" over this option.
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config SPARSEMEM_MANUAL
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bool "Sparse Memory"
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depends on ARCH_SPARSEMEM_ENABLE
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help
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This will be the only option for some systems, including
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memory hotplug systems. This is normal.
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For many other systems, this will be an alternative to
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"Discontiguous Memory". This option provides some potential
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performance benefits, along with decreased code complexity,
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but it is newer, and more experimental.
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If unsure, choose "Discontiguous Memory" or "Flat Memory"
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over this option.
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endchoice
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config DISCONTIGMEM
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def_bool y
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depends on (!SELECT_MEMORY_MODEL && ARCH_DISCONTIGMEM_ENABLE) || DISCONTIGMEM_MANUAL
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config SPARSEMEM
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def_bool y
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depends on (!SELECT_MEMORY_MODEL && ARCH_SPARSEMEM_ENABLE) || SPARSEMEM_MANUAL
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config FLATMEM
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def_bool y
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depends on (!DISCONTIGMEM && !SPARSEMEM) || FLATMEM_MANUAL
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config FLAT_NODE_MEM_MAP
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def_bool y
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depends on !SPARSEMEM
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#
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# Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
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# to represent different areas of memory. This variable allows
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# those dependencies to exist individually.
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#
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config NEED_MULTIPLE_NODES
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def_bool y
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depends on DISCONTIGMEM || NUMA
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config HAVE_MEMORY_PRESENT
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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,
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# statically allocating the mem_section[] array can potentially
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# consume vast quantities of .bss, so be careful.
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#
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# This option will also potentially produce smaller runtime code
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# with gcc 3.4 and later.
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#
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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
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# an extremely sparse physical address space.
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#
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config SPARSEMEM_EXTREME
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def_bool y
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depends on SPARSEMEM && !SPARSEMEM_STATIC
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config SPARSEMEM_VMEMMAP_ENABLE
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bool
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config SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
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def_bool y
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depends on SPARSEMEM && X86_64
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config SPARSEMEM_VMEMMAP
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bool "Sparse Memory virtual memmap"
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depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE
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default y
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help
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SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise
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pfn_to_page and page_to_pfn operations. This is the most
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efficient option when sufficient kernel resources are available.
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config HAVE_MEMBLOCK
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boolean
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config HAVE_MEMBLOCK_NODE_MAP
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boolean
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config HAVE_MEMBLOCK_PHYS_MAP
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boolean
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config HAVE_GENERIC_RCU_GUP
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boolean
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config ARCH_DISCARD_MEMBLOCK
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boolean
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config NO_BOOTMEM
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boolean
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config MEMORY_ISOLATION
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boolean
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config MOVABLE_NODE
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boolean "Enable to assign a node which has only movable memory"
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depends on HAVE_MEMBLOCK
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depends on NO_BOOTMEM
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depends on X86_64
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depends on NUMA
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default n
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help
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Allow a node to have only movable memory. Pages used by the kernel,
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such as direct mapping pages cannot be migrated. So the corresponding
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memory device cannot be hotplugged. This option allows the following
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two things:
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- When the system is booting, node full of hotpluggable memory can
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be arranged to have only movable memory so that the whole node can
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be hot-removed. (need movable_node boot option specified).
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- After the system is up, the option allows users to online all the
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memory of a node as movable memory so that the whole node can be
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hot-removed.
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Users who don't use the memory hotplug feature are fine with this
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option on since they don't specify movable_node boot option or they
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don't online memory as movable.
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Say Y here if you want to hotplug a whole node.
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Say N here if you want kernel to use memory on all nodes evenly.
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#
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# Only be set on architectures that have completely implemented memory hotplug
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# feature. If you are not sure, don't touch it.
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#
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config HAVE_BOOTMEM_INFO_NODE
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def_bool n
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# eventually, we can have this option just 'select SPARSEMEM'
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config MEMORY_HOTPLUG
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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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depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390)
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config MEMORY_HOTPLUG_SPARSE
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def_bool y
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depends on SPARSEMEM && MEMORY_HOTPLUG
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config MEMORY_HOTREMOVE
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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
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depends on MIGRATION
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#
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# If we have space for more page flags then we can enable additional
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# optimizations and functionality.
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#
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# Regular Sparsemem takes page flag bits for the sectionid if it does not
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# use a virtual memmap. Disable extended page flags for 32 bit platforms
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# that require the use of a sectionid in the page flags.
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#
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config PAGEFLAGS_EXTENDED
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def_bool y
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depends on 64BIT || SPARSEMEM_VMEMMAP || !SPARSEMEM
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# Heavily threaded applications may benefit from splitting the mm-wide
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# page_table_lock, so that faults on different parts of the user address
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# space can be handled with less contention: split it at this NR_CPUS.
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# Default to 4 for wider testing, though 8 might be more appropriate.
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# 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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#
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config SPLIT_PTLOCK_CPUS
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int
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default "999999" if !MMU
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default "999999" if ARM && !CPU_CACHE_VIPT
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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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boolean
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#
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# support for memory balloon
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config MEMORY_BALLOON
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boolean
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#
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# support for memory balloon compaction
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config BALLOON_COMPACTION
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bool "Allow for balloon memory compaction/migration"
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def_bool y
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depends on COMPACTION && MEMORY_BALLOON
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help
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Memory fragmentation introduced by ballooning might reduce
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significantly the number of 2MB contiguous memory blocks that can be
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used within a guest, thus imposing performance penalties associated
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with the reduced number of transparent huge pages that could be used
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by the guest workload. Allowing the compaction & migration for memory
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pages enlisted as being part of memory balloon devices avoids the
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scenario aforementioned and helps improving memory defragmentation.
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#
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# support for memory compaction
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config COMPACTION
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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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Allows the compaction of memory for the allocation of huge pages.
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#
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# support for page migration
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#
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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
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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
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two situations. The first is on NUMA systems to put pages nearer
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to the processors accessing. The second is when allocating huge
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pages as migration can relocate pages to satisfy a huge page
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allocation instead of reclaiming.
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config ARCH_ENABLE_HUGEPAGE_MIGRATION
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boolean
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config PHYS_ADDR_T_64BIT
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def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
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config ZONE_DMA_FLAG
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int
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default "0" if !ZONE_DMA
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default "1"
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config BOUNCE
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bool "Enable bounce buffers"
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default y
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depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM)
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help
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Enable bounce buffers for devices that cannot access
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the full range of memory available to the CPU. Enabled
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by default when ZONE_DMA or HIGHMEM is selected, but you
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may say n to override this.
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# On the 'tile' arch, USB OHCI needs the bounce pool since tilegx will often
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# have more than 4GB of memory, but we don't currently use the IOTLB to present
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# a 32-bit address to OHCI. So we need to use a bounce pool instead.
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#
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# We also use the bounce pool to provide stable page writes for jbd. jbd
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# initiates buffer writeback without locking the page or setting PG_writeback,
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# and fixing that behavior (a second time; jbd2 doesn't have this problem) is
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# a major rework effort. Instead, use the bounce buffer to snapshot pages
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# (until jbd goes away). The only jbd user is ext3.
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config NEED_BOUNCE_POOL
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bool
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default y if (TILE && USB_OHCI_HCD) || (BLK_DEV_INTEGRITY && JBD)
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config NR_QUICK
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int
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depends on QUICKLIST
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default "2" if AVR32
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default "1"
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config VIRT_TO_BUS
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bool
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help
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An architecture should select this if it implements the
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deprecated interface virt_to_bus(). All new architectures
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should probably not select this.
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config MMU_NOTIFIER
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bool
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config KSM
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bool "Enable KSM for page merging"
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depends on MMU
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help
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Enable Kernel Samepage Merging: KSM periodically scans those areas
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of an application's address space that an app has advised may be
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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.
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Recommended for use with KVM, or with other duplicative applications.
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See Documentation/vm/ksm.txt for more information: KSM is inactive
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until a program has madvised that an area is MADV_MERGEABLE, and
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root has set /sys/kernel/mm/ksm/run to 1 (if CONFIG_SYSFS is set).
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config DEFAULT_MMAP_MIN_ADDR
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int "Low address space to protect from user allocation"
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depends on MMU
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default 4096
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help
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This is the portion of low virtual memory which should be protected
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from userspace allocation. Keeping a user from writing to low pages
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can help reduce the impact of kernel NULL pointer bugs.
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For most ia64, ppc64 and x86 users with lots of address space
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a value of 65536 is reasonable and should cause no problems.
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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
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this low address space will need CAP_SYS_RAWIO or disable this
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protection by setting the value to 0.
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This value can be changed after boot using the
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/proc/sys/vm/mmap_min_addr tunable.
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config ARCH_SUPPORTS_MEMORY_FAILURE
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bool
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config MEMORY_FAILURE
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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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help
|
||
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Enables code to recover from some memory failures on systems
|
||
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with MCA recovery. This allows a system to continue running
|
||
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even when some of its memory has uncorrected errors. This requires
|
||
|
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special hardware support and typically ECC memory.
|
||
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|
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config HWPOISON_INJECT
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|
|
tristate "HWPoison pages injector"
|
||
|
|
depends on MEMORY_FAILURE && DEBUG_KERNEL && PROC_FS
|
||
|
|
select PROC_PAGE_MONITOR
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
config TRANSPARENT_HUGEPAGE
|
||
|
|
bool "Transparent Hugepage Support"
|
||
|
|
depends on HAVE_ARCH_TRANSPARENT_HUGEPAGE
|
||
|
|
select COMPACTION
|
||
|
|
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.
|
||
|
|
|
||
|
|
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
|
||
|
|
|
||
|
|
#
|
||
|
|
# UP and nommu archs use km based percpu allocator
|
||
|
|
#
|
||
|
|
config NEED_PER_CPU_KM
|
||
|
|
depends on !SMP
|
||
|
|
bool
|
||
|
|
default y
|
||
|
|
|
||
|
|
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
|
||
|
|
(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
|
||
|
|
cleancache code to put the data contained in that page into
|
||
|
|
"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
|
||
|
|
|
||
|
|
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
|
||
|
|
"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.
|
||
|
|
|
||
|
|
config CMA
|
||
|
|
bool "Contiguous Memory Allocator"
|
||
|
|
depends on HAVE_MEMBLOCK && MMU
|
||
|
|
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.
|
||
|
|
|
||
|
|
config CMA_PINPAGE_MIGRATION
|
||
|
|
bool "CMA pinned page migration (EXPERIMENTAL)"
|
||
|
|
depends on CMA
|
||
|
|
default n
|
||
|
|
help
|
||
|
|
Turns on cma page migration for pinned page.
|
||
|
|
|
||
|
|
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".
|
||
|
|
|
||
|
|
config MEM_SOFT_DIRTY
|
||
|
|
bool "Track memory changes"
|
||
|
|
depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS
|
||
|
|
select PROC_PAGE_MONITOR
|
||
|
|
help
|
||
|
|
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.
|
||
|
|
|
||
|
|
See Documentation/vm/soft-dirty.txt for more details.
|
||
|
|
|
||
|
|
config ZSWAP
|
||
|
|
bool "Compressed cache for swap pages (EXPERIMENTAL)"
|
||
|
|
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
|
||
|
|
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.
|
||
|
|
|
||
|
|
config ZSWAP_ENABLE_WRITEBACK
|
||
|
|
bool "Enable zswap writeback"
|
||
|
|
depends on ZSWAP
|
||
|
|
default n
|
||
|
|
|
||
|
|
config ZSWAP_COMPACTION
|
||
|
|
bool "Enable runtime zswap compaction"
|
||
|
|
depends on ZSWAP && ZPOOL && ZSMALLOC
|
||
|
|
default n
|
||
|
|
|
||
|
|
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 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
|
||
|
|
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 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
|
||
|
|
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.
|
||
|
|
|
||
|
|
You can check speed with zsmalloc benchmark:
|
||
|
|
https://github.com/spartacus06/zsmapbench
|
||
|
|
|
||
|
|
config GENERIC_EARLY_IOREMAP
|
||
|
|
bool
|
||
|
|
|
||
|
|
config MAX_STACK_SIZE_MB
|
||
|
|
int "Maximum user stack size for 32-bit processes (MB)"
|
||
|
|
default 80
|
||
|
|
range 8 256 if METAG
|
||
|
|
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
|
||
|
|
and metag 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.
|
||
|
|
|
||
|
|
A sane initial value is 80 MB.
|
||
|
|
|
||
|
|
|
||
|
|
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.
|
||
|
|
|
||
|
|
config ZSMALLOC_OBJ_SEQ
|
||
|
|
bool "Record the sequence number of each object in itself"
|
||
|
|
depends on ZSMALLOC
|
||
|
|
default n
|
||
|
|
help
|
||
|
|
This option records the sequence number of each zs object in the object.
|
||
|
|
The recorded number will be used for reclaim_zspage.
|
||
|
|
If unsure, say N.
|
||
|
|
|
||
|
|
config DIRECT_RECLAIM_FILE_PAGES_ONLY
|
||
|
|
bool "Reclaim file pages only on direct reclaim path"
|
||
|
|
depends on ZSWAP
|
||
|
|
default n
|
||
|
|
|
||
|
|
config INCREASE_MAXIMUM_SWAPPINESS
|
||
|
|
bool "Allow swappiness to be set up to 200"
|
||
|
|
depends on ZSWAP
|
||
|
|
default n
|
||
|
|
|
||
|
|
config FIX_INACTIVE_RATIO
|
||
|
|
bool "Fix active:inactive anon ratio to 1:1"
|
||
|
|
depends on ZSWAP
|
||
|
|
default n
|
||
|
|
|
||
|
|
config TIGHT_PGDAT_BALANCE
|
||
|
|
bool "Set more tight balanced condition to kswapd"
|
||
|
|
depends on ZSWAP
|
||
|
|
default n
|
||
|
|
|
||
|
|
config SWAP_ENABLE_READAHEAD
|
||
|
|
bool "Enable readahead on page swap in"
|
||
|
|
depends on SWAP
|
||
|
|
default y
|
||
|
|
help
|
||
|
|
When a page fault occurs, adjacent pages of SWAP_CLUSTER_MAX are
|
||
|
|
also paged in expecting those pages will be used in near future.
|
||
|
|
This behaviour is good at disk-based system, but not on in-memory
|
||
|
|
compression (e.g. zram).
|
||
|
|
|
||
|
|
config BALANCE_ANON_FILE_RECLAIM
|
||
|
|
bool "During reclaim treat anon and file backed pages equally"
|
||
|
|
depends on SWAP
|
||
|
|
help
|
||
|
|
When performing memory reclaim treat anonymous and file backed pages
|
||
|
|
equally.
|
||
|
|
Swapping anonymous pages out to memory can be efficient enough to justify
|
||
|
|
treating anonymous and file backed pages equally.
|
||
|
|
|
||
|
|
config KSWAPD_CPU_AFFINITY_MASK
|
||
|
|
string "kswapd cpu affinity mask"
|
||
|
|
depends on SMP
|
||
|
|
help
|
||
|
|
Set the cpu affinity for the kswapd task.
|
||
|
|
There can be power benefits on certain targets when limiting kswapd
|
||
|
|
to run only on certain cores.
|
||
|
|
The cpu affinity bitmask is represented by a hex string where commas
|
||
|
|
group hex digits into chunks. Each chunk defines exactly 32 bits of
|
||
|
|
the resultant bitmask.
|
||
|
|
For example to limit kswapd to the first 4 cores use the following:
|
||
|
|
CONFIG_KSWAPD_CPU_AFFINITY_MASK="f"
|
||
|
|
|
||
|
|
config FORCE_ALLOC_FROM_DMA_ZONE
|
||
|
|
bool "Force certain memory allocators to always return ZONE_DMA memory"
|
||
|
|
depends on ZONE_DMA
|
||
|
|
help
|
||
|
|
Ensure certain memory allocators always return memory from ZONE_DMA.
|
||
|
|
This option helps ensure that clients who require ZONE_DMA memory are
|
||
|
|
always using ZONE_DMA memory.
|
||
|
|
|
||
|
|
If unsure, say "n".
|
||
|
|
|
||
|
|
config PROCESS_RECLAIM
|
||
|
|
bool "Enable process reclaim"
|
||
|
|
depends on PROC_FS
|
||
|
|
default n
|
||
|
|
help
|
||
|
|
It allows to reclaim pages of the process by /proc/pid/reclaim.
|
||
|
|
|
||
|
|
(echo file > /proc/PID/reclaim) reclaims file-backed pages only.
|
||
|
|
(echo anon > /proc/PID/reclaim) reclaims anonymous pages only.
|
||
|
|
(echo all > /proc/PID/reclaim) reclaims all pages.
|
||
|
|
|
||
|
|
(echo addr size-byte > /proc/PID/reclaim) reclaims pages in
|
||
|
|
(addr, addr + size-bytes) of the process.
|
||
|
|
|
||
|
|
Any other vaule is ignored.
|