diff options
Diffstat (limited to 'mm/Kconfig')
| -rw-r--r-- | mm/Kconfig | 301 |
1 files changed, 292 insertions, 9 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index c2c8a4a1189..3e9977a9d65 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1,6 +1,6 @@ config SELECT_MEMORY_MODEL def_bool y - depends on EXPERIMENTAL || ARCH_SELECT_MEMORY_MODEL + depends on ARCH_SELECT_MEMORY_MODEL choice prompt "Memory model" @@ -20,7 +20,7 @@ config FLATMEM_MANUAL Some users of more advanced features like NUMA and memory hotplug may have different options here. - DISCONTIGMEM is an more mature, better tested system, + DISCONTIGMEM is a more mature, better tested system, but is incompatible with memory hotplug and may suffer decreased performance over SPARSEMEM. If unsure between "Sparse Memory" and "Discontiguous Memory", choose @@ -131,11 +131,59 @@ config SPARSEMEM_VMEMMAP config HAVE_MEMBLOCK boolean +config HAVE_MEMBLOCK_NODE_MAP + boolean + +config HAVE_MEMBLOCK_PHYS_MAP + boolean + +config ARCH_DISCARD_MEMBLOCK + boolean + +config NO_BOOTMEM + boolean + +config MEMORY_ISOLATION + boolean + +config MOVABLE_NODE + boolean "Enable to assign a node which has only movable memory" + depends on HAVE_MEMBLOCK + depends on NO_BOOTMEM + depends on X86_64 + depends on NUMA + default n + help + Allow a node to have only movable memory. Pages used by the kernel, + such as direct mapping pages cannot be migrated. So the corresponding + memory device cannot be hotplugged. This option allows the following + two things: + - When the system is booting, node full of hotpluggable memory can + be arranged to have only movable memory so that the whole node can + be hot-removed. (need movable_node boot option specified). + - After the system is up, the option allows users to online all the + memory of a node as movable memory so that the whole node can be + hot-removed. + + Users who don't use the memory hotplug feature are fine with this + option on since they don't specify movable_node boot option or they + don't online memory as movable. + + Say Y here if you want to hotplug a whole node. + Say N here if you want kernel to use memory on all nodes evenly. + +# +# 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 + # eventually, we can have this option just 'select SPARSEMEM' config MEMORY_HOTPLUG bool "Allow for memory hot-add" depends on SPARSEMEM || X86_64_ACPI_NUMA - depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG + depends on ARCH_ENABLE_MEMORY_HOTPLUG depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390) config MEMORY_HOTPLUG_SPARSE @@ -144,6 +192,8 @@ config MEMORY_HOTPLUG_SPARSE config MEMORY_HOTREMOVE bool "Allow for memory hot remove" + select MEMORY_ISOLATION + select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64) depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE depends on MIGRATION @@ -169,17 +219,36 @@ config PAGEFLAGS_EXTENDED # config SPLIT_PTLOCK_CPUS int + default "999999" if !MMU default "999999" if ARM && !CPU_CACHE_VIPT default "999999" if PARISC && !PA20 - default "999999" if DEBUG_SPINLOCK || DEBUG_LOCK_ALLOC default "4" +config ARCH_ENABLE_SPLIT_PMD_PTLOCK + boolean + +# +# support for memory balloon compaction +config BALLOON_COMPACTION + bool "Allow for balloon memory compaction/migration" + def_bool y + depends on COMPACTION && VIRTIO_BALLOON + 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. + # # support for memory compaction config COMPACTION bool "Allow for memory compaction" + def_bool y select MIGRATION - depends on EXPERIMENTAL && HUGETLB_PAGE && MMU + depends on MMU help Allows the compaction of memory for the allocation of huge pages. @@ -189,7 +258,7 @@ config COMPACTION config MIGRATION bool "Page migration" def_bool y - depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION + depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU help Allows the migration of the physical location of pages of processes while the virtual addresses are not changed. This is useful in @@ -198,6 +267,9 @@ config MIGRATION pages as migration can relocate pages to satisfy a huge page allocation instead of reclaiming. +config ARCH_ENABLE_HUGEPAGE_MIGRATION + boolean + config PHYS_ADDR_T_64BIT def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT @@ -207,8 +279,27 @@ config ZONE_DMA_FLAG default "1" config BOUNCE - def_bool y + bool "Enable bounce buffers" + default y depends on BLOCK && MMU && (ZONE_DMA || HIGHMEM) + 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. + +# On the 'tile' arch, USB OHCI needs the bounce pool since tilegx will often +# have more than 4GB of memory, but we don't currently use the IOTLB to present +# a 32-bit address to OHCI. So we need to use a bounce pool instead. +# +# We also use the bounce pool to provide stable page writes for jbd. jbd +# initiates buffer writeback without locking the page or setting PG_writeback, +# and fixing that behavior (a second time; jbd2 doesn't have this problem) is +# a major rework effort. Instead, use the bounce buffer to snapshot pages +# (until jbd goes away). The only jbd user is ext3. +config NEED_BOUNCE_POOL + bool + default y if (TILE && USB_OHCI_HCD) || (BLK_DEV_INTEGRITY && JBD) config NR_QUICK int @@ -217,8 +308,12 @@ config NR_QUICK default "1" config VIRT_TO_BUS - def_bool y - depends on !ARCH_NO_VIRT_TO_BUS + bool + help + An architecture should select this if it implements the + deprecated interface virt_to_bus(). All new architectures + should probably not select this. + config MMU_NOTIFIER bool @@ -263,6 +358,7 @@ config MEMORY_FAILURE depends on MMU depends on ARCH_SUPPORTS_MEMORY_FAILURE bool "Enable recovery from hardware memory errors" + select MEMORY_ISOLATION help Enables code to recover from some memory failures on systems with MCA recovery. This allows a system to continue running @@ -302,6 +398,44 @@ config NOMMU_INITIAL_TRIM_EXCESS 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 # @@ -309,3 +443,152 @@ 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 ZBUD + tristate + 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 ZSWAP + bool "Compressed cache for swap pages (EXPERIMENTAL)" + depends on FRONTSWAP && CRYPTO=y + select CRYPTO_LZO + select ZBUD + 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 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 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. |