[PATCH v3 0/3] docs/mm/damon/design: add explanation of nr_snapshots

[PATCH v3 0/3] docs/mm/damon/design: add explanation of nr_snapshots

[SJ Park]

Add an explanation of nr_snapshots to avoid misunderstandings.

Changes from v2
- v2: https://lore.kernel.org/20260812104002.15225-1-aethernet65535@gmail.com
- Collect R-b: from SJ.
- Rebase to latest mm-new.
Changes from v1:
- v1: https://lore.kernel.org/damon/20260811101841.804596-1-aethernet65535@gmail.com
- Patch 1 word order adjustment: Repositioned "completely" ("tried to be
  completely applied" -> "completely tried to be applied").
- Patch 2: Use two spaces between sentences.
- Patch 3: Add the "Reviewed-by:" of SJ, because he added this in v1.
- Patch 3: Make some minor modifications, Patch 3 can be applied after
  Patch 2.

Liew Rui Yan (3):
  docs/mm/damon/design: accurate semantics of nr_snapshots
  docs/mm/damon/design: difference between watermarks and nr_snapshots
  docs/mm/damon/design: fix typo of max_nr_snapshots

 Documentation/mm/damon/design.rst | 9 +++++----
 include/linux/damon.h             | 5 +++--
 2 files changed, 8 insertions(+), 6 deletions(-)


base-commit: 5c4fade039dbd572ba5ad9cf993fbb56e6a5613f
-- 
2.47.3

[PATCH v3 1/3] docs/mm/damon/design: accurate semantics of nr_snapshots

[SJ Park]

From: Liew Rui Yan <aethernet65535@gmail.com>

Change "tried to be applied" -> "completely tried to be applied" to
maintain consistency between the documentation and the code.

Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
---
 Documentation/mm/damon/design.rst | 4 ++--
 include/linux/damon.h             | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index a8c163475ef2b..af94fc27890b8 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -848,8 +848,8 @@ scheme's execution.
 - ``nr_applied``: Total number of regions that the scheme is applied.
 - ``sz_applied``: Total size of regions that the scheme is applied.
 - ``qt_exceeds``: Total number of times the quota of the scheme has exceeded.
-- ``nr_snapshots``: Total number of DAMON snapshots that the scheme is tried to
-  be applied.
+- ``nr_snapshots``: Total number of DAMON snapshots that the scheme is
+  completely tried to be applied.
 - ``max_nr_snapshots``: Upper limit of ``nr_snapshots``.
 
 "A scheme is tried to be applied to a region" means DAMOS core logic determined
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 6842a336291e8..d3f45f4dcdafa 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -359,7 +359,8 @@ struct damos_watermarks {
  *		Total bytes that passed ops layer-handled DAMOS filters.
  * @qt_exceeds: Total number of times the quota of the scheme has exceeded.
  * @nr_snapshots:
- *		Total number of DAMON snapshots that the scheme has tried.
+ *		Total number of DAMON snapshots that the scheme is completely
+ *		tried to be applied.
  *
  * "Tried an action to a region" in this context means the DAMOS core logic
  * determined the region as eligible to apply the action.  The access pattern
-- 
2.47.3

Re: [PATCH v3 1/3] docs/mm/damon/design: accurate semantics of nr_snapshots

[sashiko-bot]

> From: Liew Rui Yan <aethernet65535@gmail.com>
> 
> Change "tried to be applied" -> "completely tried to be applied" to
> maintain consistency between the documentation and the code.
> 
> Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
> Reviewed-by: SJ Park <sj@kernel.org>
> Signed-off-by: SJ Park <sj@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260831150227.83416-1-sj@kernel.org?part=1

[PATCH v3 2/3] docs/mm/damon/design: difference between watermarks and nr_snapshots

[SJ Park]

From: Liew Rui Yan <aethernet65535@gmail.com>

Explain the difference between nr_snapshots reaches max_nr_snapshots and
watermarks.

Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
---
 Documentation/mm/damon/design.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index af94fc27890b8..74170a2285501 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -874,7 +874,8 @@ the action to the region will fail.
 
 Unlike normal stats, ``max_nr_snapshots`` is set by users.  If it is set as
 non-zero and ``nr_snapshots`` be same to or greater than ``nr_snapshots``, the
-scheme is deactivated.
+scheme is deactivated.  Note that, unlike watermarks, even if a scheme's
+``nr_snapshots`` reaches ``max_nr_snapshots``, monitoring will not stop.
 
 To know how user-space can read the stats via :ref:`DAMON sysfs interface
 <sysfs_interface>`, refer to :ref:s`stats <sysfs_stats>` part of the
-- 
2.47.3

Re: [PATCH v3 2/3] docs/mm/damon/design: difference between watermarks and nr_snapshots

[sashiko-bot]

> From: Liew Rui Yan <aethernet65535@gmail.com>
> 
> Explain the difference between nr_snapshots reaches max_nr_snapshots and
> watermarks.
> 
> Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
> Reviewed-by: SJ Park <sj@kernel.org>
> Signed-off-by: SJ Park <sj@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260831150227.83416-1-sj@kernel.org?part=2

[PATCH v3 3/3] docs/mm/damon/design: fix typo of max_nr_snapshots

[SJ Park]

From: Liew Rui Yan <aethernet65535@gmail.com>

Fixes a typo (nr_snapshots -> max_nr_snapshots) and corrects a grammar
error.

Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
---
 Documentation/mm/damon/design.rst | 4 ++--
 include/linux/damon.h             | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index 74170a2285501..63cbb7b536da2 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -873,8 +873,8 @@ action is ``pageout`` while all pages of the region are unreclaimable, applying
 the action to the region will fail.
 
 Unlike normal stats, ``max_nr_snapshots`` is set by users.  If it is set as
-non-zero and ``nr_snapshots`` be same to or greater than ``nr_snapshots``, the
-scheme is deactivated.  Note that, unlike watermarks, even if a scheme's
+non-zero and ``nr_snapshots`` equals or is greater than ``max_nr_snapshots``,
+the scheme is deactivated.  Note that, unlike watermarks, even if a scheme's
 ``nr_snapshots`` reaches ``max_nr_snapshots``, monitoring will not stop.
 
 To know how user-space can read the stats via :ref:`DAMON sysfs interface
diff --git a/include/linux/damon.h b/include/linux/damon.h
index d3f45f4dcdafa..7b1b6050a8286 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -551,7 +551,7 @@ struct damos_migrate_dests {
  *
  * After applying the &action to each region, &stat is updated.
  *
- * If &max_nr_snapshots is set as non-zero and &stat.nr_snapshots be same to or
+ * If &max_nr_snapshots is set as non-zero and &stat.nr_snapshots equals or is
  * greater than it, the scheme is deactivated.
  */
 struct damos {
-- 
2.47.3

Re: [PATCH v3 3/3] docs/mm/damon/design: fix typo of max_nr_snapshots

[sashiko-bot]

> From: Liew Rui Yan <aethernet65535@gmail.com>
> 
> Fixes a typo (nr_snapshots -> max_nr_snapshots) and corrects a grammar
> error.
> 
> Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
> Reviewed-by: SJ Park <sj@kernel.org>
> Signed-off-by: SJ Park <sj@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260831150227.83416-1-sj@kernel.org?part=3