Lines Matching +full:in +full:- +full:memory
1 # SPDX-License-Identifier: GPL-2.0-only
3 menu "Memory Management options"
10 prompt "Memory model"
17 Linux manages its memory internally. Most users will
22 bool "Flat Memory"
25 This option is best suited for non-NUMA systems with
27 system in terms of performance and resource consumption
30 For systems that have holes in their physical address
31 spaces and for features like NUMA and memory hotplug,
32 choose "Sparse Memory".
34 If unsure, choose this option (Flat Memory) over any other.
37 bool "Discontiguous Memory"
41 memory systems, over FLATMEM. These systems have holes
42 in their physical address spaces, and this option provides
45 Although "Discontiguous Memory" is still used by several
46 architectures, it is considered deprecated in favor of
47 "Sparse Memory".
49 If unsure, choose "Sparse Memory" over this option.
52 bool "Sparse Memory"
56 memory hot-plug systems. This is normal.
59 holes is their physical address space and allows memory
60 hot-plug and hot-remove.
62 If unsure, choose "Flat Memory" over this option.
72 File-LRU is a mechanism that put file page in global lru list,
73 and anon page in memcg lru list(if MEMCG is enable), what's
77 bool "Enable Memcg Management in HyperHold"
80 Add more attributes in memory cgroup, these attribute is used
81 to show information, shrink memory, swapin page and so on.
84 bool "Enable zswapd thread to reclaim anon pages in background"
88 zswapd is a kernel thread that reclaim anonymous pages in the
100 bool "Memory reclaim delay accounting"
103 Memory reclaim delay accounting. Never use it as a kernel module.
123 # to represent different areas of memory. This variable allows
144 # Architecture platforms which require a two level mem_section in SPARSEMEM
156 bool "Sparse Memory virtual memmap"
174 # Don't discard allocated memory used to track "memory" and "reserved" memblocks
175 # after early boot, so it can still be used to test for validity of memory.
176 # Also, memblocks are updated with memory hot(un)plug.
180 # Keep arch NUMA mapping infrastructure post-init.
188 # Only be set on architectures that have completely implemented memory hotplug
196 bool "Allow for memory hot-add"
208 bool "Online the newly added memory blocks by default"
211 This option sets the default policy setting for memory hotplug
212 onlining policy (/sys/devices/system/memory/auto_online_blocks) which
213 determines what happens to newly added memory regions. Policy setting
215 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
217 Say Y here if you want all hot-plugged memory blocks to appear in
219 Say N here if you want the default policy to keep all hot-plugged
220 memory blocks in 'offline' state.
223 bool "Allow for memory hot remove"
228 # Heavily threaded applications may benefit from splitting the mm-wide
232 # ARM's adjust_pte (unused if VIPT) depends on mm-wide page_table_lock.
233 # PA-RISC 7xxx's spinlock_t would enlarge struct page from 32 to 44 bytes.
235 # a per-page lock leads to problems when multiple tables need to be locked
251 # support for memory balloon
256 # support for memory balloon compaction
258 bool "Allow for balloon memory compaction/migration"
262 Memory fragmentation introduced by ballooning might reduce
263 significantly the number of 2MB contiguous memory blocks that can be
266 by the guest workload. Allowing the compaction & migration for memory
267 pages enlisted as being part of memory balloon devices avoids the
268 scenario aforementioned and helps improving memory defragmentation.
271 # support for memory compaction
273 bool "Allow for memory compaction"
278 Compaction is the only memory management component to form
279 high order (larger physically contiguous) memory blocks
282 invocations for high order memory requests. You shouldn't
285 linux-mm@kvack.org.
296 memory can be freed within the host for other uses.
307 while the virtual addresses are not changed. This is useful in
331 the full range of memory available to the CPU. Enabled
357 saving memory until one or another app needs to modify the content.
368 This is the portion of low virtual memory which should be protected
388 bool "Enable recovery from hardware memory errors"
392 Enables code to recover from some memory failures on systems
394 even when some of its memory has uncorrected errors. This requires
395 special hardware support and typically ECC memory.
408 of memory on which to store mappings, but it can only ask the system
409 allocator for chunks in 2^N*PAGE_SIZE amounts - which is frequently
418 long-term mappings means that the space is wasted.
428 See Documentation/admin-guide/mm/nommu-mmap.rst for more information.
439 applications by speeding up page faults during memory
443 If memory constrained on embedded, you may want to say N.
456 memory footprint of applications without a guaranteed
465 memory footprint of applications without a guaranteed
476 Swap transparent huge pages in one piece, without splitting.
493 Cleancache can be thought of as a page-granularity victim cache
496 memory. So when the PFRA "evicts" a page, it first attempts to use
497 cleancache code to put the data contained in that page into
498 "transcendent memory", memory that is not directly accessible or
500 time-varying size. And when a cleancache-enabled
501 filesystem wishes to access a page in a file on disk, it first
504 When a transcendent memory driver is available (such as zcache or
505 Xen transcendent memory), a significant I/O reduction
507 are reduced to a single pointer-compare-against-NULL resulting
508 in a negligible performance hit.
518 "transcendent memory", memory that is not directly accessible or
520 time-varying size. When space in transcendent memory is available,
522 available, all frontswap calls are reduced to a single pointer-
523 compare-against-NULL resulting in a negligible performance hit
529 bool "Contiguous Memory Allocator"
534 This enables the Contiguous Memory Allocator which allows other
535 subsystems to allocate big physically-contiguous blocks of memory.
536 CMA reserves a region of memory and allows only movable pages to
537 be allocated from it. This way, the kernel can use the memory for
547 Turns on debug messages in CMA. This produces KERN_DEBUG
566 number of CMA area in the system.
568 If unsure, leave the default value "7" in UMA and "19" in NUMA.
581 bool "Track memory changes"
585 This option enables memory changes tracking by introducing a
586 soft-dirty bit on pte-s. This bit it set when someone writes
590 See Documentation/admin-guide/mm/soft-dirty.rst for more details.
598 pages that are in the process of being swapped out and attempts to
599 compress them into a dynamically allocated RAM-based memory pool.
600 This can result in a significant I/O reduction on swap device and,
601 in the case where decompressing from RAM is faster that swap device
605 v3.11) that interacts heavily with memory reclaim. While these
606 interactions don't cause any known issues on simple memory setups,
623 If in doubt, select 'LZO'.
728 tristate "Common API for compressed memory storage"
730 Compressed memory storage API. This allows using either zbud or
752 tristate "Memory allocator for compressed pages"
755 zsmalloc is a slab-based memory allocator designed to store
756 compressed RAM pages. zsmalloc uses virtual memory mapping
757 in order to reduce fragmentation. However, this results in a
758 non-standard allocator interface where a handle, not a pointer, is
759 returned by an alloc(). This handle must be mapped in order to
767 This option enables code in the zsmalloc to collect various
768 statistics about whats happening in zsmalloc and exports that
776 int "Maximum user stack size for 32-bit processes (MB)"
781 This is the maximum stack size in Megabytes in the VM layout of 32-bit
783 arch). The stack will be located at the highest memory address minus
785 smaller value in which case that is used.
796 Ordinarily all struct pages are initialised during early boot in a
799 a subset of memmap at boot and then initialise the rest in parallel.
800 This has a potential performance impact on tasks running early in the
811 be useful to tune memory cgroup limits and/or for job placement
814 See Documentation/admin-guide/mm/idle_page_tracking.rst for
821 bool "Device memory (pmem, HMM, etc...) hotplug support"
829 Device memory hotplug support allows for establishing pmem,
830 or other device driver discovered memory regions, in the
832 "device-physical" addresses which is needed for using a DAX
833 mapping in an O_DIRECT operation, among other things.
849 bool "Unaddressable device memory (GPU memory, ...)"
855 memory; i.e., memory that is only accessible from the device (or
870 bool "Collect percpu memory statistics"
874 be used to help understand percpu memory usage.
888 bool "Read-only THP for filesystems (EXPERIMENTAL)"
892 Allow khugepaged to put read-only file-backed pages in THP.
895 support of file THPs will be developed in the next few release
919 Allow naming anonymous virtual memory areas.
921 This feature allows assigning names to virtual memory areas. Assigned
923 and help identifying individual anonymous memory areas.
924 Assigning a name to anonymous virtual memory area might prevent that
925 area from being merged with adjacent virtual memory areas due to the
926 difference in their name.
928 # For lmkd to trigger in-kernel lowmem info
931 bool "Low Memory Killer"
937 bool "Low Memory Killer Debug"
959 Set a threshold to monitoring RSS in per pid
962 bool "Purgeable memory feature"
970 bool "Purgeable memory debug"
974 Debug info for purgeable memory