in your computer. If unsure say Y.
config ZSWAP
- bool "Compressed cache for swap pages (EXPERIMENTAL)"
+ bool "Compressed cache for swap pages"
depends on SWAP
- select FRONTSWAP
select CRYPTO
select ZPOOL
help
in the case where decompressing from RAM is faster than 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_DEFAULT_ON
bool "Enable the compressed cache for swap pages by default"
depends on ZSWAP
The selection made here can be overridden by using the kernel
command line 'zswap.enabled=' option.
+config ZSWAP_SHRINKER_DEFAULT_ON
+ bool "Shrink the zswap pool on memory pressure"
+ depends on ZSWAP
+ default n
+ help
+ If selected, the zswap shrinker will be enabled, and the pages
+ stored in the zswap pool will become available for reclaim (i.e
+ written back to the backing swap device) on memory pressure.
+
+ This means that zswap writeback could happen even if the pool is
+ not yet full, or the cgroup zswap limit has not been reached,
+ reducing the chance that cold pages will reside in the zswap pool
+ and consume memory indefinitely.
+
choice
prompt "Default compressor"
depends on ZSWAP
choice
prompt "Default allocator"
depends on ZSWAP
+ default ZSWAP_ZPOOL_DEFAULT_ZSMALLOC if MMU
default ZSWAP_ZPOOL_DEFAULT_ZBUD
help
Selects the default allocator for the compressed cache for
information to userspace via debugfs.
If unsure, say N.
-menu "SLAB allocator options"
-
-choice
- prompt "Choose SLAB allocator"
- default SLUB
+config ZSMALLOC_CHAIN_SIZE
+ int "Maximum number of physical pages per-zspage"
+ default 8
+ range 4 16
+ depends on ZSMALLOC
help
- This option allows to select a slab allocator.
+ This option sets the upper limit on the number of physical pages
+ that a zmalloc page (zspage) can consist of. The optimal zspage
+ chain size is calculated for each size class during the
+ initialization of the pool.
-config SLAB
- bool "SLAB"
- depends on !PREEMPT_RT
- select HAVE_HARDENED_USERCOPY_ALLOCATOR
- help
- The regular slab allocator that is established and known to work
- well in all environments. It organizes cache hot objects in
- per cpu and per node queues.
+ Changing this option can alter the characteristics of size classes,
+ such as the number of pages per zspage and the number of objects
+ per zspage. This can also result in different configurations of
+ the pool, as zsmalloc merges size classes with similar
+ characteristics.
+
+ For more information, see zsmalloc documentation.
+
+menu "Slab allocator options"
config SLUB
- bool "SLUB (Unqueued Allocator)"
- select HAVE_HARDENED_USERCOPY_ALLOCATOR
- help
- SLUB is a slab allocator that minimizes cache line usage
- instead of managing queues of cached objects (SLAB approach).
- Per cpu caching is realized using slabs of objects instead
- of queues of objects. SLUB can use memory efficiently
- and has enhanced diagnostics. SLUB is the default choice for
- a slab allocator.
+ def_bool y
-config SLOB
+config SLUB_TINY
+ bool "Configure for minimal memory footprint"
depends on EXPERT
- bool "SLOB (Simple Allocator)"
- depends on !PREEMPT_RT
+ select SLAB_MERGE_DEFAULT
help
- SLOB replaces the stock allocator with a drastically simpler
- allocator. SLOB is generally more space efficient but
- does not perform as well on large systems.
+ Configures the slab allocator in a way to achieve minimal memory
+ footprint, sacrificing scalability, debugging and other features.
+ This is intended only for the smallest system that had used the
+ SLOB allocator and is not recommended for systems with more than
+ 16MB RAM.
-endchoice
+ If unsure, say N.
config SLAB_MERGE_DEFAULT
bool "Allow slab caches to be merged"
default y
- depends on SLAB || SLUB
help
For reduced kernel memory fragmentation, slab caches can be
merged when they share the same size and other characteristics.
config SLAB_FREELIST_RANDOM
bool "Randomize slab freelist"
- depends on SLAB || SLUB
+ depends on !SLUB_TINY
help
Randomizes the freelist order used on creating new pages. This
security feature reduces the predictability of the kernel slab
config SLAB_FREELIST_HARDENED
bool "Harden slab freelist metadata"
- depends on SLAB || SLUB
+ depends on !SLUB_TINY
help
Many kernel heap attacks try to target slab cache metadata and
other infrastructure. This options makes minor performance
sacrifices to harden the kernel slab allocator against common
- freelist exploit methods. Some slab implementations have more
- sanity-checking than others. This option is most effective with
- CONFIG_SLUB.
+ freelist exploit methods.
config SLUB_STATS
default n
- bool "Enable SLUB performance statistics"
- depends on SLUB && SYSFS
+ bool "Enable performance statistics"
+ depends on SYSFS && !SLUB_TINY
help
- SLUB statistics are useful to debug SLUBs allocation behavior in
+ The statistics are useful to debug slab allocation behavior in
order find ways to optimize the allocator. This should never be
enabled for production use since keeping statistics slows down
the allocator by a few percentage points. The slabinfo command
config SLUB_CPU_PARTIAL
default y
- depends on SLUB && SMP
- bool "SLUB per cpu partial cache"
+ depends on SMP && !SLUB_TINY
+ bool "Enable per cpu partial caches"
help
Per cpu partial caches accelerate objects allocation and freeing
that is local to a processor at the price of more indeterminism
which requires the taking of locks that may cause latency spikes.
Typically one would choose no for a realtime system.
-endmenu # SLAB allocator options
+config RANDOM_KMALLOC_CACHES
+ default n
+ depends on !SLUB_TINY
+ bool "Randomize slab caches for normal kmalloc"
+ help
+ A hardening feature that creates multiple copies of slab caches for
+ normal kmalloc allocation and makes kmalloc randomly pick one based
+ on code address, which makes the attackers more difficult to spray
+ vulnerable memory objects on the heap for the purpose of exploiting
+ memory vulnerabilities.
+
+ Currently the number of copies is set to 16, a reasonably large value
+ that effectively diverges the memory objects allocated for different
+ subsystems or modules into different caches, at the expense of a
+ limited degree of memory and CPU overhead that relates to hardware and
+ system workload.
+
+endmenu # Slab allocator options
config SHUFFLE_PAGE_ALLOCATOR
bool "Page allocator randomization"
the presence of a memory-side-cache. There are also incidental
security benefits as it reduces the predictability of page
allocations to compliment SLAB_FREELIST_RANDOM, but the
- default granularity of shuffling on the "MAX_ORDER - 1" i.e,
- 10th order of pages is selected based on cache utilization
- benefits on x86.
+ default granularity of shuffling on the MAX_PAGE_ORDER i.e, 10th
+ order of pages is selected based on cache utilization benefits
+ on x86.
While the randomization improves cache utilization it may
negatively impact workloads on platforms without a cache. For
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.
+#
+# Select this config option from the architecture Kconfig, if it is preferred
+# to enable the feature of HugeTLB/dev_dax vmemmap optimization.
+#
+config ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
+ bool
+
+config ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
+ bool
config HAVE_MEMBLOCK_PHYS_MAP
bool
endif # MEMORY_HOTPLUG
+config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
+ bool
+
# 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.
# support for memory balloon compaction
config BALLOON_COMPACTION
bool "Allow for balloon memory compaction/migration"
- def_bool y
+ default y
depends on COMPACTION && MEMORY_BALLOON
help
Memory fragmentation introduced by ballooning might reduce
# support for memory compaction
config COMPACTION
bool "Allow for memory compaction"
- def_bool y
+ default y
select MIGRATION
depends on MMU
help
it and then we would be really interested to hear about that at
linux-mm@kvack.org.
+config COMPACT_UNEVICTABLE_DEFAULT
+ int
+ depends on COMPACTION
+ default 0 if PREEMPT_RT
+ default 1
+
#
# support for free page reporting
config PAGE_REPORTING
bool "Free page reporting"
- def_bool n
help
Free page reporting allows for the incremental acquisition of
free pages from the buddy allocator for the purpose of reporting
#
config MIGRATION
bool "Page migration"
- def_bool y
+ default y
depends on (NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION || CMA) && MMU
help
Allows the migration of the physical location of pages of processes
HUGETLB_PAGE_ORDER when there are multiple HugeTLB page sizes available
on a platform.
- Note that the pageblock_order cannot exceed MAX_ORDER - 1 and will be
- clamped down to MAX_ORDER - 1.
+ Note that the pageblock_order cannot exceed MAX_PAGE_ORDER and will be
+ clamped down to MAX_PAGE_ORDER.
config CONTIG_ALLOC
def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
+config PCP_BATCH_SCALE_MAX
+ int "Maximum scale factor of PCP (Per-CPU pageset) batch allocate/free"
+ default 5
+ range 0 6
+ help
+ In page allocator, PCP (Per-CPU pageset) is refilled and drained in
+ batches. The batch number is scaled automatically to improve page
+ allocation/free throughput. But too large scale factor may hurt
+ latency. This option sets the upper limit of scale factor to limit
+ the maximum latency.
+
config PHYS_ADDR_T_64BIT
def_bool 64BIT
config MMU_NOTIFIER
bool
- select SRCU
select INTERVAL_TREE
config KSM
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
+ For most 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.
Programs which use vm86 functionality or have some need to map
madvise(MADV_HUGEPAGE) but it won't risk to increase the
memory footprint of applications without a guaranteed
benefit.
+
+ config TRANSPARENT_HUGEPAGE_NEVER
+ bool "never"
+ help
+ Disable Transparent Hugepage by default. It can still be
+ enabled at runtime via sysfs.
endchoice
config THP_SWAP
def_bool y
- depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP
+ depends on TRANSPARENT_HUGEPAGE && ARCH_WANTS_THP_SWAP && SWAP && 64BIT
help
Swap transparent huge pages in one piece, without splitting.
XXX: For now, swap cluster backing transparent huge page
config HAVE_SETUP_PER_CPU_AREA
bool
-config FRONTSWAP
- bool
-
config CMA
bool "Contiguous Memory Allocator"
depends on MMU
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_DEBUGFS
bool "CMA debugfs interface"
depends on CMA && DEBUG_FS
config CMA_AREAS
int "Maximum count of the CMA areas"
depends on CMA
- default 19 if NUMA
- default 7
+ default 20 if NUMA
+ default 8
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" in UMA and "19" in NUMA.
+ If unsure, leave the default value "8" in UMA and "20" in NUMA.
config MEM_SOFT_DIRTY
bool "Track memory changes"
See Documentation/admin-guide/mm/idle_page_tracking.rst for
more details.
+# Architectures which implement cpu_dcache_is_aliasing() to query
+# whether the data caches are aliased (VIVT or VIPT with dcache
+# aliasing) need to select this.
+config ARCH_HAS_CPU_CACHE_ALIASING
+ bool
+
config ARCH_HAS_CACHE_LINE_SIZE
bool
bool
depends on MMU
+config GET_FREE_REGION
+ depends on SPARSEMEM
+ bool
+
config DEVICE_PRIVATE
bool "Unaddressable device memory (GPU memory, ...)"
depends on ZONE_DEVICE
+ select GET_FREE_REGION
help
Allows creation of struct pages to represent unaddressable device
config ARCH_HAS_PKEYS
bool
+config ARCH_USES_PG_ARCH_X
+ bool
+ help
+ Enable the definition of PG_arch_x page flags with x > 1. Only
+ suitable for 64-bit architectures with CONFIG_FLATMEM or
+ CONFIG_SPARSEMEM_VMEMMAP enabled, otherwise there may not be
+ enough room for additional bits in page->flags.
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EXPERT
pin_user_pages*(), or pinned via get_user_pages*(), as specified
by other command line arguments.
- See tools/testing/selftests/vm/gup_test.c
+ See tools/testing/selftests/mm/gup_test.c
comment "GUP_TEST needs to have DEBUG_FS enabled"
depends on !GUP_TEST && !DEBUG_FS
-config GUP_GET_PTE_LOW_HIGH
+config GUP_GET_PXX_LOW_HIGH
bool
+config DMAPOOL_TEST
+ tristate "Enable a module to run time tests on dma_pool"
+ depends on HAS_DMA
+ help
+ Provides a test module that will allocate and free many blocks of
+ various sizes and report how long it takes. This is intended to
+ provide a consistent way to measure how changes to the
+ dma_pool_alloc/free routines affect performance.
+
config ARCH_HAS_PTE_SPECIAL
bool
config IO_MAPPING
bool
+config MEMFD_CREATE
+ bool "Enable memfd_create() system call" if EXPERT
+
config SECRETMEM
- def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED
+ default y
+ bool "Enable memfd_secret() system call" if EXPERT
+ depends on ARCH_HAS_SET_DIRECT_MAP
+ help
+ Enable the memfd_secret() system call with the ability to create
+ memory areas visible only in the context of the owning process and
+ not mapped to other processes and other kernel page tables.
config ANON_VMA_NAME
bool "Anonymous VMA name support"
area from being merged with adjacent virtual memory areas due to the
difference in their name.
-config USERFAULTFD
- bool "Enable userfaultfd() system call"
- depends on MMU
- help
- Enable the userfaultfd() system call that allows to intercept and
- handle page faults in userland.
-
config HAVE_ARCH_USERFAULTFD_WP
bool
help
help
Arch has userfaultfd minor fault support
-config PTE_MARKER
- bool
-
+menuconfig USERFAULTFD
+ bool "Enable userfaultfd() system call"
+ depends on MMU
help
- Allows to create marker PTEs for file-backed memory.
+ Enable the userfaultfd() system call that allows to intercept and
+ handle page faults in userland.
+if USERFAULTFD
config PTE_MARKER_UFFD_WP
bool "Userfaultfd write protection support for shmem/hugetlbfs"
default y
depends on HAVE_ARCH_USERFAULTFD_WP
- select PTE_MARKER
help
Allows to create marker PTEs for userfaultfd write protection
purposes. It is required to enable userfaultfd write protection on
file-backed memory types like shmem and hugetlbfs.
+endif # USERFAULTFD
+
+# multi-gen LRU {
+config LRU_GEN
+ bool "Multi-Gen LRU"
+ depends on MMU
+ # make sure folio->flags has enough spare bits
+ depends on 64BIT || !SPARSEMEM || SPARSEMEM_VMEMMAP
+ help
+ A high performance LRU implementation to overcommit memory. See
+ Documentation/admin-guide/mm/multigen_lru.rst for details.
+
+config LRU_GEN_ENABLED
+ bool "Enable by default"
+ depends on LRU_GEN
+ help
+ This option enables the multi-gen LRU by default.
+
+config LRU_GEN_STATS
+ bool "Full stats for debugging"
+ depends on LRU_GEN
+ help
+ Do not enable this option unless you plan to look at historical stats
+ from evicted generations for debugging purpose.
+
+ This option has a per-memcg and per-node memory overhead.
+
+config LRU_GEN_WALKS_MMU
+ def_bool y
+ depends on LRU_GEN && ARCH_HAS_HW_PTE_YOUNG
+# }
+
+config ARCH_SUPPORTS_PER_VMA_LOCK
+ def_bool n
+
+config PER_VMA_LOCK
+ def_bool y
+ depends on ARCH_SUPPORTS_PER_VMA_LOCK && MMU && SMP
+ help
+ Allow per-vma locking during page fault handling.
+
+ This feature allows locking each virtual memory area separately when
+ handling page faults instead of taking mmap_lock.
+
+config LOCK_MM_AND_FIND_VMA
+ bool
+ depends on !STACK_GROWSUP
+
+config IOMMU_MM_DATA
+ bool
source "mm/damon/Kconfig"
projects / linux-2.6-microblaze.git / blobdiff