Commit 5bce4947 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

Docs/admin-guide/mm/damon/usage: omit DAMOS filter details in favor of design doc 

DAMON usage document is describing some details about DAMOS filters, which
are also documented on the design doc.  Deduplicate the details in favor
of the design doc.

Link: https://lkml.kernel.org/r/20250109175126.57878-10-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1c2ac23d

Documentation/admin-guide/mm/damon/usage.rst

+14 −15
Original line number Diff line number Diff line
@@ -411,13 +411,17 @@ Each filter directory contains six files, namely ``type``, ``matcing``, 
file, you can write one of five special keywords: ``anon`` for anonymous pages,

``memcg`` for specific memory cgroup, ``young`` for young pages, ``addr`` for

specific address range (an open-ended interval), or ``target`` for specific

DAMON monitoring target filtering.  In case of the memory cgroup filtering, you

can specify the memory cgroup of the interest by writing the path of the memory

cgroup from the cgroups mount point to ``memcg_path`` file.  In case of the

address range filtering, you can specify the start and end address of the range

to ``addr_start`` and ``addr_end`` files, respectively.  For the DAMON

monitoring target filtering, you can specify the index of the target between

the list of the DAMON context's monitoring targets list to ``target_idx`` file.

DAMON monitoring target filtering.  Meaning of the types are same to the

description on the :ref:`design doc <damon_design_damos_filters>`.



In case of the memory cgroup filtering, you can specify the memory cgroup of

the interest by writing the path of the memory cgroup from the cgroups mount

point to ``memcg_path`` file.  In case of the address range filtering, you can

specify the start and end address of the range to ``addr_start`` and

``addr_end`` files, respectively.  For the DAMON monitoring target filtering,

you can specify the index of the target between the list of the DAMON context's

monitoring targets list to ``target_idx`` file.



You can write ``Y`` or ``N`` to ``matching`` file to filter out pages that does

or does not match to the type, respectively.  Then, the scheme's action will

not be applied to the pages that specified to be filtered out.
@@ -434,14 +438,9 @@ pages of all memory cgroups except ``/having_care_already``.:: 
    echo /having_care_already > 1/memcg_path

    echo Y > 1/matching



Note that ``anon`` and ``memcg`` filters are currently supported only when

``paddr`` :ref:`implementation <sysfs_context>` is being used.



Also, memory regions that are filtered out by ``addr`` or ``target`` filters

are not counted as the scheme has tried to those, while regions that filtered

out by other type filters are counted as the scheme has tried to.  The

difference is applied to :ref:`stats <damos_stats>` and

:ref:`tried regions <sysfs_schemes_tried_regions>`.

Refer to the :ref:`DAMOS filters design documentation

<damon_design_damos_filters>` for more details including when each of the

filters are supported and differences on stats.



.. _sysfs_schemes_stats: