Docs/mm/damon: move DAMON operation sets list from the usage to the design document

The list of DAMON operation sets and their explanation, which may better
to be on design document, is written on the usage document.  Move the
detail to design document and make the usage document only reference the
design document.

[sj@kernel.org: fix a typo on a reference link]
  Link: https://lkml.kernel.org/r/20240221170852.55529-2-sj@kernel.org
Link: https://lkml.kernel.org/r/20240217005842.87348-4-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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

@@ -180,19 +180,14 @@ In each context directory, two files (``avail_operations`` and ``operations``)
 and three directories (``monitoring_attrs``, ``targets``, and ``schemes``)
 exist.
 
-DAMON supports multiple types of monitoring operations, including those for
-virtual address space and the physical address space.  You can get the list of
-available monitoring operations set on the currently running kernel by reading
+DAMON supports multiple types of :ref:`monitoring operations
+<damon_design_configurable_operations_set>`, including those for virtual address
+space and the physical address space.  You can get the list of available
+monitoring operations set on the currently running kernel by reading
 ``avail_operations`` file.  Based on the kernel configuration, the file will
-list some or all of below keywords.
-
- - vaddr: Monitor virtual address spaces of specific processes
- - fvaddr: Monitor fixed virtual address ranges
- - paddr: Monitor the physical address space of the system
-
-Please refer to :ref:`regions sysfs directory <sysfs_regions>` for detailed
-differences between the operations sets in terms of the monitoring target
-regions.
+list different available operation sets.  Please refer to the :ref:`design
+<damon_operations_set>` for the list of all available operation sets and their
+brief explanations.
 
 You can set and get what type of monitoring operations DAMON will use for the
 context by writing one of the keywords listed in ``avail_operations`` file and

Documentation/mm/damon/design.rst

@@ -31,6 +31,8 @@ DAMON subsystem is configured with three layers including
   interfaces for the user space, on top of the core layer.
 
 
+.. _damon_design_configurable_operations_set:
+
 Configurable Operations Set
 ---------------------------
 
@@ -63,6 +65,8 @@ modules that built on top of the core layer using the API, which can be easily
 used by the user space end users.
 
 
+.. _damon_operations_set:
+
 Operations Set Layer
 ====================
 
@@ -71,8 +75,12 @@ The monitoring operations are defined in two parts:
 1. Identification of the monitoring target address range for the address space.
 2. Access check of specific address range in the target space.
 
-DAMON currently provides the implementations of the operations for the physical
-and virtual address spaces. Below two subsections describe how those work.
+DAMON currently provides below three operation sets.  Below two subsections
+describe how those work.
+
+ - vaddr: Monitor virtual address spaces of specific processes
+ - fvaddr: Monitor fixed virtual address ranges
+ - paddr: Monitor the physical address space of the system
 
 
 VMA-based Target Address Range Construction