linux/Documentation/admin-guide/mm
Liew Rui Yan 6f1e182387 Docs/mm/damon: document min_nr_regions constraint and rationale
The current DAMON implementation requires 'min_nr_regions' to be at least
3.  However, this constraint is not explicitly documented in the
admin-guide documents, nor is its design rationale explained in the design
document.

Add a section in design.rst to explain the rationale: the virtual address
space monitoring design needs to handle at least three regions to
accommodate two large unmapped areas.  While this is specific to 'vaddr',
DAMON currently enforces it across all operation sets for consistency.

Also update reclaim.rst and lru_sort.rst by adding cross-references to
this constraint within their respective 'min_nr_regions' parameter
description sections, ensuring users are aware of the lower bound.

This change is motivated from a recent discussion [1].

Link: https://lkml.kernel.org/r/20260320052428.213230-1-aethernet65535@gmail.com
Link: https://lore.kernel.org/damon/20260319151528.86490-1-sj@kernel.org/T/#t [1]
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05 13:53:34 -07:00
..
damon Docs/mm/damon: document min_nr_regions constraint and rationale 2026-04-05 13:53:34 -07:00
cma_debugfs.rst mm, cma: support multiple contiguous ranges, if requested 2025-03-16 22:06:25 -07:00
concepts.rst docs/admin-guide/mm: remove useless markup 2023-02-02 10:18:05 -07:00
hugetlbpage.rst mm: hugetlb: add hugetlb_alloc_threads cmdline option 2025-03-17 00:05:36 -07:00
idle_page_tracking.rst - Daniel Verkamp has contributed a memfd series ("mm/memfd: add 2023-02-23 17:09:35 -08:00
index.rst mm/swap: do not choose swap device according to numa node 2025-11-16 17:28:27 -08:00
kho.rst kho: remove finalize state and clients 2026-04-05 13:53:04 -07:00
ksm.rst Docs: typos/spelling 2024-05-02 10:02:29 -06:00
memory-hotplug.rst mm: rename CONFIG_BALLOON_COMPACTION to CONFIG_BALLOON_MIGRATION 2026-01-31 14:22:36 -08:00
multigen_lru.rst mm: add max swappiness arg to lru_gen for anonymous memory only 2025-05-12 23:50:36 -07:00
nommu-mmap.rst docs: fix 're-use' -> 'reuse' in documentation 2026-02-02 09:54:15 -07:00
numa_memory_policy.rst docs: mm: fix typo in numa_memory_policy.rst 2026-04-05 13:53:23 -07:00
numaperf.rst - Daniel Verkamp has contributed a memfd series ("mm/memfd: add 2023-02-23 17:09:35 -08:00
pagemap.rst pagemap: update BUDDY flag documentation 2025-11-24 15:08:56 -08:00
shrinker_debugfs.rst docs/admin-guide/mm: remove useless markup 2023-02-02 10:18:05 -07:00
slab.rst doc: Move SLUB documentation to the admin guide 2025-06-18 13:06:26 +02:00
soft-dirty.rst docs/admin-guide/mm: remove useless markup 2023-02-02 10:18:05 -07:00
transhuge.rst mm: shmem/tmpfs hugepage defaults config choice 2025-11-16 17:28:23 -08:00
userfaultfd.rst userfaultfd: UFFDIO_MOVE uABI 2023-12-29 11:58:24 -08:00
zswap.rst Docs/admin-guide/mm/zswap: s/red-black tree/xarray/ 2025-11-16 17:27:57 -08:00