Commit 7b06c471 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
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Docs/mm/damon/design: document 'address unit' parameter 

Add 'addr_unit' parameter description on DAMON design document.

Link: https://lkml.kernel.org/r/20250828171242.59810-9-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarQuanmin Yan <yanquanmin1@huawei.com>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: ze zuo <zuoze1@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 540a2aeb

Documentation/mm/damon/design.rst

+13 −1
Original line number Diff line number Diff line
@@ -67,7 +67,7 @@ processes, NUMA nodes, files, and backing memory devices would be supportable. 
Also, if some architectures or devices support special optimized access check

features, those will be easily configurable.



DAMON currently provides below three operation sets.  Below two subsections

DAMON currently provides below three operation sets.  Below three subsections

describe how those work.



 - vaddr: Monitor virtual address spaces of specific processes
@@ -135,6 +135,18 @@ the interference is the responsibility of sysadmins. However, it solves the 
conflict with the reclaim logic using ``PG_idle`` and ``PG_young`` page flags,

as Idle page tracking does.



Address Unit

------------



DAMON core layer uses ``unsinged long`` type for monitoring target address

ranges.  In some cases, the address space for a given operations set could be

too large to be handled with the type.  ARM (32-bit) with large physical

address extension is an example.  For such cases, a per-operations set

parameter called ``address unit`` is provided.  It represents the scale factor

that need to be multiplied to the core layer's address for calculating real

address on the given address space.  Support of ``address unit`` parameter is

up to each operations set implementation.  ``paddr`` is the only operations set

implementation that supports the parameter.



.. _damon_core_logic: