Docs/mm/damon: misc readability improvements
Subsystems (4)
SeongJae Park
maintainercover Docs/mm/damon: misc readability improvements
Fix trivial mistakes and improve layout of information on different documents for DAMON.
SeongJae Park (5):
Docs/mm/damon/maintainer-profile: fix reference links for
mm-[un]stable tree
Docs/mm/damon: move the list of DAMOS actions to design doc Docs/mm/damon: move DAMON operation sets list from the usage to the
design document
Docs/mm/damon: move monitoring target regions setup detail from the
usage to the design document
Docs/admin-guide/mm/damon/usage: fix wrong quotas diabling condition
Documentation/admin-guide/mm/damon/usage.rst | 85 ++++++------------- Documentation/mm/damon/design.rst | 50 +++++++++-- Documentation/mm/damon/maintainer-profile.rst | 8 +- 3 files changed, 73 insertions(+), 70 deletions(-)
base-commit: 1a09812aed136b8caa4b976c78135b1e99d16412
Signature · 1 line
2.39.2
SeongJae Park
maintainerPATCH 1/5 Docs/mm/damon/maintainer-profile: fix reference links for mm-[un]stable tree
A couplt of sentences on maintainer-profile.rst are having reference links for mm-unstable and mm-stable trees with wrong rst markup. Fix those.
Signed-off-by SeongJae Park <[email protected]>
--- Documentation/mm/damon/maintainer-profile.rst | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
Documentation/mm/damon/maintainer-profile.rst +4 -4
@@ -21,8 +21,8 @@ be queued in mm-stable [3]_ , and finally pull-requested to the mainline by the memory management subsystem maintainer. Note again the patches for review should be made against the mm-unstable -tree[1] whenever possible. damon/next is only for preview of others' works in -progress. +tree [1]_ whenever possible. damon/next is only for preview of others' works +in progress. Submit checklist addendum -------------------------
@@ -41,8 +41,8 @@ Further doing below and putting the results will be helpful. Key cycle dates --------------- -Patches can be sent anytime. Key cycle dates of the mm-unstable[1] and -mm-stable[3] trees depend on the memory management subsystem maintainer. +Patches can be sent anytime. Key cycle dates of the mm-unstable [1]_ and +mm-stable [3]_ trees depend on the memory management subsystem maintainer. Review cadence --------------
Signature · 1 line
2.39.2
SeongJae Park
maintainerPATCH 2/5 Docs/mm/damon: move the list of DAMOS actions to design doc
In reply to SeongJae ParkDAMOS operation actions are explained nearly twice on the DAMON usage document, once for the sysfs interface, and then again for the debugfs interface. Duplication is bad. Also it would better to keep this kind of concept level details in design document and keep the usage document small and focus on only the usage. Move the list to design document and update usage document to reference it.
Signed-off-by SeongJae Park <[email protected]>
--- Documentation/admin-guide/mm/damon/usage.rst | 47 ++++++-------------- Documentation/mm/damon/design.rst | 26 +++++++++-- 2 files changed, 36 insertions(+), 37 deletions(-)
Documentation/admin-guide/mm/damon/usage.rst +13 -34
@@ -302,27 +302,8 @@ In each scheme directory, five directories (``access_pattern``, ``quotas``, The ``action`` file is for setting and getting the scheme's :ref:`action <damon_design_damos_action>`. The keywords that can be written to and read -from the file and their meaning are as below. - -Note that support of each action depends on the running DAMON operations set -:ref:`implementation <sysfs_context>`. - - - ``willneed``: Call ``madvise()`` for the region with ``MADV_WILLNEED``. - Supported by ``vaddr`` and ``fvaddr`` operations set. - - ``cold``: Call ``madvise()`` for the region with ``MADV_COLD``. - Supported by ``vaddr`` and ``fvaddr`` operations set. - - ``pageout``: Call ``madvise()`` for the region with ``MADV_PAGEOUT``. - Supported by ``vaddr``, ``fvaddr`` and ``paddr`` operations set. - - ``hugepage``: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``. - Supported by ``vaddr`` and ``fvaddr`` operations set. - - ``nohugepage``: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``. - Supported by ``vaddr`` and ``fvaddr`` operations set. - - ``lru_prio``: Prioritize the region on its LRU lists. - Supported by ``paddr`` operations set. - - ``lru_deprio``: Deprioritize the region on its LRU lists. - Supported by ``paddr`` operations set. - - ``stat``: Do nothing but count the statistics. - Supported by all operations sets. +from the file and their meaning are same to those of the list on +:ref:`design doc <damon_design_damos_action>`. The ``apply_interval_us`` file is for setting and getting the scheme's :ref:`apply_interval <damon_design_damos>` in microseconds.
@@ -763,19 +744,17 @@ Action ~~~~~~ The ``<action>`` is a predefined integer for memory management :ref:`actions -<damon_design_damos_action>`. The supported numbers and their meanings are as -below. - - - 0: Call ``madvise()`` for the region with ``MADV_WILLNEED``. Ignored if - ``target`` is ``paddr``. - - 1: Call ``madvise()`` for the region with ``MADV_COLD``. Ignored if - ``target`` is ``paddr``. - - 2: Call ``madvise()`` for the region with ``MADV_PAGEOUT``. - - 3: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``. Ignored if - ``target`` is ``paddr``. - - 4: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``. Ignored if - ``target`` is ``paddr``. - - 5: Do nothing but count the statistics +<damon_design_damos_action>`. The mapping between the ``<action>`` values and +the memory management actions is as below. For the detailed meaning of the +action and DAMON operations set supporting each action, please refer to the +list on :ref:`design doc <damon_design_damos_action>`. + + - 0: ``willneed`` + - 1: ``cold`` + - 2: ``pageout`` + - 3: ``hugepage`` + - 4: ``nohugepage`` + - 5: ``stat`` Quota ~~~~~
Documentation/mm/damon/design.rst +23 -3
@@ -294,9 +294,29 @@ not mandated to support all actions of the list. Hence, the availability of specific DAMOS action depends on what operations set is selected to be used together. -Applying an action to a region is considered as changing the region's -characteristics. Hence, DAMOS resets the age of regions when an action is -applied to those. +The list of the supported actions, their meaning, and DAMON operations sets +that supports each action are as below. + + - ``willneed``: Call ``madvise()`` for the region with ``MADV_WILLNEED``. + Supported by ``vaddr`` and ``fvaddr`` operations set. + - ``cold``: Call ``madvise()`` for the region with ``MADV_COLD``. + Supported by ``vaddr`` and ``fvaddr`` operations set. + - ``pageout``: Call ``madvise()`` for the region with ``MADV_PAGEOUT``. + Supported by ``vaddr``, ``fvaddr`` and ``paddr`` operations set. + - ``hugepage``: Call ``madvise()`` for the region with ``MADV_HUGEPAGE``. + Supported by ``vaddr`` and ``fvaddr`` operations set. + - ``nohugepage``: Call ``madvise()`` for the region with ``MADV_NOHUGEPAGE``. + Supported by ``vaddr`` and ``fvaddr`` operations set. + - ``lru_prio``: Prioritize the region on its LRU lists. + Supported by ``paddr`` operations set. + - ``lru_deprio``: Deprioritize the region on its LRU lists. + Supported by ``paddr`` operations set. + - ``stat``: Do nothing but count the statistics. + Supported by all operations sets. + +Applying the actions except ``stat`` to a region is considered as changing the +region's characteristics. Hence, DAMOS resets the age of regions when any such +actions are applied to those. .. _damon_design_damos_access_pattern:
Signature · 1 line
2.39.2
SeongJae Park
maintainerPATCH 3/5 Docs/mm/damon: move DAMON operation sets list from the usage to the design document
In reply to SeongJae ParkThe 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.
Signed-off-by SeongJae Park <[email protected]>
--- Documentation/admin-guide/mm/damon/usage.rst | 19 +++++++------------ Documentation/mm/damon/design.rst | 12 ++++++++++-- 2 files changed, 17 insertions(+), 14 deletions(-)
Documentation/admin-guide/mm/damon/usage.rst +7 -12
@@ -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_confiurable_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 +10 -2
@@ -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
Signature · 1 line
2.39.2
SeongJae Park
maintainerPATCH 4/5 Docs/mm/damon: move monitoring target regions setup detail from the usage to the design document
In reply to SeongJae ParkDesign doc is aimed to have all concept level details, while the usage doc is focused on only how the features can be used. Some details about monitoring target regions construction is on the usage doc. Move the details about the monitoring target regions construction differences for DAMON operations set from the usage to the design doc.
Signed-off-by SeongJae Park <[email protected]>
--- Documentation/admin-guide/mm/damon/usage.rst | 16 +++++----------- Documentation/mm/damon/design.rst | 12 +++++++++--- 2 files changed, 14 insertions(+), 14 deletions(-)
Documentation/admin-guide/mm/damon/usage.rst +5 -11
@@ -242,17 +242,11 @@ process to the ``pid_target`` file. targets/<N>/regions ------------------- -When ``vaddr`` monitoring operations set is being used (``vaddr`` is written to -the ``contexts/<N>/operations`` file), DAMON automatically sets and updates the -monitoring target regions so that entire memory mappings of target processes -can be covered. However, users could want to set the initial monitoring region -to specific address ranges. - -In contrast, DAMON do not automatically sets and updates the monitoring target -regions when ``fvaddr`` or ``paddr`` monitoring operations sets are being used -(``fvaddr`` or ``paddr`` have written to the ``contexts/<N>/operations``). -Therefore, users should set the monitoring target regions by themselves in the -cases. +In case of ``fvaddr`` or ``paddr`` monitoring operations sets, users are +required to set the monitoring target address ranges. In case of ``vaddr`` +operations set, it is not mandatory, but users can optionally set the initial +monitoring region to specific address ranges. Please refer to the :ref:`design +<damon_design_vaddr_target_regions_construction>` for more details. For such cases, users can explicitly set the initial monitoring target regions as they want, by writing proper values to the files under this directory.
Documentation/mm/damon/design.rst +9 -3
@@ -83,12 +83,18 @@ describe how those work. - paddr: Monitor the physical address space of the system + .. _damon_design_vaddr_target_regions_construction: + VMA-based Target Address Range Construction ------------------------------------------- -This is only for the virtual address space monitoring operations -implementation. That for the physical address space simply asks users to -manually set the monitoring target address ranges. +A mechanism of ``vaddr`` DAMON operations set that automatically initializes +and updates the monitoring target address regions so that entire memory +mappings of the target processes can be covered. + +This mechanism is only for the ``vaddr`` operations set. In cases of +``fvaddr`` and ``paddr`` operation sets, users are asked to manually set the +monitoring target address ranges. Only small parts in the super-huge virtual address space of the processes are mapped to the physical memory and accessed. Thus, tracking the unmapped
Signature · 1 line
2.39.2
SeongJae Park
maintainerPATCH 5/5 Docs/admin-guide/mm/damon/usage: fix wrong quotas diabling condition
In reply to SeongJae ParkAfter the introduction of DAMOS quotas, DAMOS quotas is not disabled if both size and time quotas are zero but the quota goal is set. The new rule is also applied to DAMON sysfs interface, but the usage doc is not updated. Update it.
Signed-off-by SeongJae Park <[email protected]>
--- Documentation/admin-guide/mm/damon/usage.rst | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
Documentation/admin-guide/mm/damon/usage.rst +2 -1
@@ -329,7 +329,8 @@ respectively. Then, DAMON tries to use only up to ``time quota`` milliseconds for applying the ``action`` to memory regions of the ``access_pattern``, and to apply the action to only up to ``bytes`` bytes of memory regions within the ``reset_interval_ms``. Setting both ``ms`` and ``bytes`` zero disables the -quota limits. +quota limits unless at least one :ref:`goal <sysfs_schemes_quota_goals>` is +set. Under ``weights`` directory, three files (``sz_permil``, ``nr_accesses_permil``, and ``age_permil``) exist.
Signature · 1 line
2.39.2