linux-5.10/mm/Kconfig

1 # SPDX-License-Identifier: GPL-2.0-only
25 	  This option is best suited for non-NUMA systems with
56 	  memory hot-plug systems.  This is normal.
60 	  hot-plug and hot-remove.
83 # Both the NUMA code and DISCONTIGMEM use arrays of pg_data_t's
138 # Keep arch NUMA mapping infrastructure post-init.
154 	bool "Allow for memory hot-add"
173 	  See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
175 	  Say Y here if you want all hot-plugged memory blocks to appear in
177 	  Say N here if you want the default policy to keep all hot-plugged
186 # Heavily threaded applications may benefit from splitting the mm-wide
190 # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
191 # PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
193 # a per-page lock leads to problems when multiple tables need to be locked
243 	  linux-mm@kvack.org.
316 	  Recommended for use with KVM, or with other duplicative applications.
333 	  Programs which use vm86 functionality or have some need to map
353 	  special hardware support and typically ECC memory.
367 	  allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently
376 	  long-term mappings means that the space is wasted.
379 	  (/proc/sys/vm/nr_trim_pages) which specifies the minimum number of
386 	  See Documentation/admin-guide/mm/nommu-mmap.rst for more information.
394 	  Transparent Hugepages allows the kernel to use huge pages and
441 # UP and nommu archs use km based percpu allocator
451 	  Cleancache can be thought of as a page-granularity victim cache
454 	  memory.  So when the PFRA "evicts" a page, it first attempts to use
458 	  time-varying size.  And when a cleancache-enabled
465 	  are reduced to a single pointer-compare-against-NULL resulting
478 	  time-varying size.  When space in transcendent memory is available,
480 	  available, all frontswap calls are reduced to a single pointer-
481 	  compare-against-NULL resulting in a negligible performance hit
493 	  subsystems to allocate big physically-contiguous blocks of memory.
495 	  be allocated from it. This way, the kernel can use the memory for
534 	  soft-dirty bit on pte-s. This bit it set when someone writes
538 	  See Documentation/admin-guide/mm/soft-dirty.rst for more details.
547 	  compress them into a dynamically allocated RAM-based memory pool.
580 	  Use the Deflate algorithm as the default compression algorithm.
586 	  Use the LZO algorithm as the default compression algorithm.
592 	  Use the 842 algorithm as the default compression algorithm.
598 	  Use the LZ4 algorithm as the default compression algorithm.
604 	  Use the LZ4HC algorithm as the default compression algorithm.
610 	  Use the zstd algorithm as the default compression algorithm.
642 	  Use the zbud allocator as the default allocator.
648 	  Use the z3fold allocator as the default allocator.
654 	  Use the zsmalloc allocator as the default allocator.
703 	  zsmalloc is a slab-based memory allocator designed to store
706 	  non-standard allocator interface where a handle, not a pointer, is
724 	int "Maximum user stack size for 32-bit processes (MB)"
729 	  This is the maximum stack size in Megabytes in the VM layout of 32-bit
762 	  See Documentation/admin-guide/mm/idle_page_tracking.rst for
780 	  "device-physical" addresses which is needed for using a DAX
836 	bool "Read-only THP for filesystems (EXPERIMENTAL)"
840 	  Allow khugepaged to put read-only file-backed pages in THP.