| From: SeongJae Park <sj@kernel.org> |
| Subject: Docs/mm/damon/design: update the layout based on the layers |
| Date: Thu, 25 May 2023 21:43:08 +0000 |
| |
| DAMON design document is describing only the operations set layer and |
| monitoring part of the core logic. Update the layout based on the DAMON's |
| layers, so that more parts of DAMON including DAMOS core logic and DAMON |
| modules can easily be added. |
| |
| Link: https://lkml.kernel.org/r/20230525214314.5204-5-sj@kernel.org |
| Signed-off-by: SeongJae Park <sj@kernel.org> |
| Cc: Jonathan Corbet <corbet@lwn.net> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| --- |
| |
| Documentation/mm/damon/design.rst | 24 ++++++++++++++---------- |
| 1 file changed, 14 insertions(+), 10 deletions(-) |
| |
| --- a/Documentation/mm/damon/design.rst~docs-mm-damon-design-update-the-layout-based-on-the-layers |
| +++ a/Documentation/mm/damon/design.rst |
| @@ -19,8 +19,8 @@ DAMON subsystem is configured with three |
| interfaces for the user space, on top of the core layer. |
| |
| |
| -Configurable Layers |
| -=================== |
| +Configurable Operations Set |
| +--------------------------- |
| |
| DAMON provides data access monitoring functionality while making the accuracy |
| and the overhead controllable. The fundamental access monitorings require |
| @@ -42,8 +42,8 @@ Also, if some architectures or devices s |
| primitives, those will be easily configurable. |
| |
| |
| -Reference Implementations of Address Space Specific Monitoring Operations |
| -========================================================================= |
| +Operations Set Layer |
| +==================== |
| |
| The monitoring operations are defined in two parts: |
| |
| @@ -105,8 +105,12 @@ conflict with the reclaim logic using `` |
| as Idle page tracking does. |
| |
| |
| -Address Space Independent Core Mechanisms |
| -========================================= |
| +Core Logics |
| +=========== |
| + |
| + |
| +Monitoring |
| +---------- |
| |
| Below four sections describe each of the DAMON core mechanisms and the five |
| monitoring attributes, ``sampling interval``, ``aggregation interval``, |
| @@ -115,7 +119,7 @@ regions``. |
| |
| |
| Access Frequency Monitoring |
| ---------------------------- |
| +~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| The output of DAMON says what pages are how frequently accessed for a given |
| duration. The resolution of the access frequency is controlled by setting |
| @@ -142,7 +146,7 @@ size of the target workload grows. |
| |
| |
| Region Based Sampling |
| ---------------------- |
| +~~~~~~~~~~~~~~~~~~~~~ |
| |
| To avoid the unbounded increase of the overhead, DAMON groups adjacent pages |
| that assumed to have the same access frequencies into a region. As long as the |
| @@ -159,7 +163,7 @@ assumption is not guaranteed. |
| |
| |
| Adaptive Regions Adjustment |
| ---------------------------- |
| +~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| Even somehow the initial monitoring target regions are well constructed to |
| fulfill the assumption (pages in same region have similar access frequencies), |
| @@ -178,7 +182,7 @@ keeping the bounds users set for their t |
| |
| |
| Dynamic Target Space Updates Handling |
| -------------------------------------- |
| +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| The monitoring target address range could dynamically changed. For example, |
| virtual memory could be dynamically mapped and unmapped. Physical memory could |
| _ |
