All of lore.kernel.org
 help / color / mirror / Atom feed
* [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code
@ 2026-06-24 14:19 SeongJae Park
  2026-06-24 14:19 ` [RFC PATCH 01/11] Docs/mm/damon/design: update for DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP SeongJae Park
                   ` (10 more replies)
  0 siblings, 11 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:19 UTC (permalink / raw)
  Cc: SeongJae Park, Liam R. Howlett, Andrew Morton, Brendan Higgins,
	David Gow, David Hildenbrand, Jonathan Corbet, Lorenzo Stoakes,
	Michal Hocko, Mike Rapoport, Shuah Khan, Shuah Khan,
	Suren Baghdasaryan, Vlastimil Babka, damon, kunit-dev, linux-doc,
	linux-kernel, linux-kselftest, linux-mm

Patches 1 and 2 update the design and ABI documents for recently added
DAMON features.  Patches 3-7 add or update more unit and self tests for
DAMON to cover recently changed or added functions and sysfs files.
Patch 8 optimizes damon_commit_target_regions() to skip unnecessary
adjacent ranges setup.  Patches 9-11 clean and fix up recently added
DAMON sysfs interface code for readability.

SeongJae Park (11):
  Docs/mm/damon/design: update for DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP
  Docs/ABI/damon: document probe files
  mm/damon/tests/core-kunit: test damon_rand()
  selftests/damon/sysfs.sh: test multiple probe dirs creation
  selftests/damon/sysfs.sh: test {core,ops}_filters/ directories
  selftests/damon/sysfs.sh: test dests dir
  selftests/damon/sysfs.sh: test all files in quota goal dir
  mm/damon/core: reduce range setup in damon_commit_target_regions()
  mm/damon/sysfs: split probe setup function out
  mm/damon/sysfs: split out filters setup function
  mm/damon/sysfs: fix typos in probe_{add,rm}_dirs: s/attr/probe/

 .../ABI/testing/sysfs-kernel-mm-damon         |  40 +++++++
 Documentation/mm/damon/design.rst             |   2 +
 mm/damon/core.c                               |  22 +++-
 mm/damon/sysfs.c                              | 102 ++++++++++--------
 mm/damon/tests/core-kunit.h                   |  21 ++++
 tools/testing/selftests/damon/sysfs.sh        |  70 +++++++++++-
 6 files changed, 206 insertions(+), 51 deletions(-)


base-commit: 197a7eb91f786e5deeb1dfea35076c01ebd37ce0
-- 
2.47.3


^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH 01/11] Docs/mm/damon/design: update for DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
@ 2026-06-24 14:19 ` SeongJae Park
  2026-06-24 14:19 ` [RFC PATCH 02/11] Docs/ABI/damon: document probe files SeongJae Park
                   ` (9 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:19 UTC (permalink / raw)
  Cc: SeongJae Park, Liam R. Howlett, Andrew Morton, David Hildenbrand,
	Jonathan Corbet, Lorenzo Stoakes, Michal Hocko, Mike Rapoport,
	Shuah Khan, Suren Baghdasaryan, Vlastimil Babka, damon, linux-doc,
	linux-kernel, linux-mm

Commit 9138e27a3bc3 ("mm/damon: add node_eligible_mem_bp goal metric")
introduced DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP but forgot updating the
DAMON design document for that.  Update.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 Documentation/mm/damon/design.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index c16a3bb288d07..06a8894eb06f9 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -686,6 +686,8 @@ mechanism tries to make ``current_value`` of ``target_metric`` be same to
   (1/10,000).
 - ``inactive_mem_bp``: Inactive to active + inactive (LRU) memory size ratio in
   bp (1/10,000).
+- ``node_eligible_mem_bp``: Scheme target access pattern-eligible memory ratio
+  of a node in bp (1/10,000).
 
 ``nid`` is optionally required for only ``node_mem_used_bp``,
 ``node_mem_free_bp``, ``node_memcg_used_bp`` and ``node_memcg_free_bp`` to
-- 
2.47.3


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 02/11] Docs/ABI/damon: document probe files
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
  2026-06-24 14:19 ` [RFC PATCH 01/11] Docs/mm/damon/design: update for DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP SeongJae Park
@ 2026-06-24 14:19 ` SeongJae Park
  2026-06-24 14:19 ` [RFC PATCH 03/11] mm/damon/tests/core-kunit: test damon_rand() SeongJae Park
                   ` (8 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:19 UTC (permalink / raw)
  Cc: SeongJae Park, Liam R. Howlett, Andrew Morton, David Hildenbrand,
	Lorenzo Stoakes, Michal Hocko, Mike Rapoport, Suren Baghdasaryan,
	Vlastimil Babka, damon, linux-kernel, linux-mm

DAMON ABI document is not updated for the DAMON probe sysfs files.
Update.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 .../ABI/testing/sysfs-kernel-mm-damon         | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-damon b/Documentation/ABI/testing/sysfs-kernel-mm-damon
index b73e6bc28ea5f..2815f6bc05c18 100644
--- a/Documentation/ABI/testing/sysfs-kernel-mm-damon
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-damon
@@ -157,6 +157,46 @@ Description:	Writing a value to this file sets the maximum number of
 		monitoring regions of the DAMON context as the value.  Reading
 		this file returns the value.
 
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/monitoring_attrs/probes/nr_probes
+Date:		May 2026
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing a number 'N' to this file creates the number of
+		directories for each DAMON probe named '0' to 'N-1' under the
+		probes/ directory.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/monitoring_attrs/probes/<P>/filters/nr_filters
+Date:		May 2026
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing a number 'N' to this file creates the number of
+		directories for each DAMON probe filter named '0' to 'N-1'
+		under the filters/ directory.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/monitoring_attrs/probes/<P>/filters/<F>/type
+Date:		May 2026
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing to and reading from this file sets and gets the type of
+		the memory of the interest.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/monitoring_attrs/probes/<P>/filters/<F>/path
+Date:		May 2026
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	If 'memmcg' is written to the 'type' file, writing to and
+		reading from this file sets and geets the path to the memory
+		cgroup of the interest.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/monitoring_attrs/probes/<P>/filters/<F>/matching
+Date:		May 2026
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing 'Y' or 'N' to this file sets whether the filter is for
+		the memory of the 'type', or all except the 'type'.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/monitoring_attrs/probes/<P>/filters/<F>/allow
+Date:		May 2026
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing 'Y' or 'N' to this file sets whether to allow or reject
+		hitting the probe for the memory that satisfies the 'type' and
+		the 'matching' of the directory.
+
 What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/targets/nr_targets
 Date:		Mar 2022
 Contact:	SeongJae Park <sj@kernel.org>
-- 
2.47.3


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 03/11] mm/damon/tests/core-kunit: test damon_rand()
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
  2026-06-24 14:19 ` [RFC PATCH 01/11] Docs/mm/damon/design: update for DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP SeongJae Park
  2026-06-24 14:19 ` [RFC PATCH 02/11] Docs/ABI/damon: document probe files SeongJae Park
@ 2026-06-24 14:19 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 04/11] selftests/damon/sysfs.sh: test multiple probe dirs creation SeongJae Park
                   ` (7 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:19 UTC (permalink / raw)
  Cc: SeongJae Park, Andrew Morton, Brendan Higgins, David Gow, damon,
	kunit-dev, linux-kernel, linux-kselftest, linux-mm

Commit 9012c4e647df ("mm/damon: replace damon_rand() with a per-ctx
lockless PRNG") optimized DAMON for better performance.  Add a kunit
test for ensuring the pseudo randomness quality.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/tests/core-kunit.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index df16cc070eeb0..a1ba807d59a13 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -1488,6 +1488,26 @@ static void damon_test_walk_control_obsolete(struct kunit *test)
 	damon_destroy_ctx(ctx);
 }
 
+static void damon_test_rand(struct kunit *test)
+{
+	struct damon_ctx ctx;
+	int counts[10] = {};
+	int i;
+
+	prandom_seed_state(&ctx.rnd_state, get_random_u64());
+	for (i = 0; i < 10000; i++) {
+		unsigned long rnd = damon_rand(&ctx, 0, 10);
+
+		KUNIT_EXPECT_GE(test, rnd, 0);
+		KUNIT_EXPECT_LE(test, rnd, 9);
+		counts[rnd]++;
+	}
+	for (i = 0; i < 10; i++) {
+		KUNIT_EXPECT_GE(test, counts[i], 900);
+		KUNIT_EXPECT_LE(test, counts[i], 1100);
+	}
+}
+
 static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_test_target),
 	KUNIT_CASE(damon_test_regions),
@@ -1518,6 +1538,7 @@ static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_test_apply_min_nr_regions),
 	KUNIT_CASE(damon_test_is_last_region),
 	KUNIT_CASE(damon_test_walk_control_obsolete),
+	KUNIT_CASE(damon_test_rand),
 	{},
 };
 
-- 
2.47.3


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 04/11] selftests/damon/sysfs.sh: test multiple probe dirs creation
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (2 preceding siblings ...)
  2026-06-24 14:19 ` [RFC PATCH 03/11] mm/damon/tests/core-kunit: test damon_rand() SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 05/11] selftests/damon/sysfs.sh: test {core,ops}_filters/ directories SeongJae Park
                   ` (6 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Shuah Khan, damon, linux-kernel, linux-kselftest,
	linux-mm

DAMON sysfs essential file operations test (sysfs.sh) was extended to
test DAMON probes sysfs directory, by commit 14885da09b0f
("selftests/damon/sysfs.sh: test probes dir").  Unlike other DAMON sysfs
files, it is testing only a single directory case.  Extend it for
multiple directories.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/sysfs.sh | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/testing/selftests/damon/sysfs.sh b/tools/testing/selftests/damon/sysfs.sh
index 2eaaa5ae3c5ed..d528dfea44c3b 100755
--- a/tools/testing/selftests/damon/sysfs.sh
+++ b/tools/testing/selftests/damon/sysfs.sh
@@ -346,8 +346,13 @@ test_probes()
 	ensure_write_succ "$probes_dir/nr_probes" "1" "valid input"
 	test_probe "$probes_dir/0"
 
+	ensure_write_succ "$probes_dir/nr_probes" "2" "valid input"
+	test_probe "$probes_dir/0"
+	test_probe "$probes_dir/1"
+
 	ensure_write_succ "$probes_dir/nr_probes" "0" "valid input"
 	ensure_dir "$probes_dir/0" "not_exist"
+	ensure_dir "$probes_dir/1" "not_exist"
 }
 
 test_monitoring_attrs()
-- 
2.47.3


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 05/11] selftests/damon/sysfs.sh: test {core,ops}_filters/ directories
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (3 preceding siblings ...)
  2026-06-24 14:20 ` [RFC PATCH 04/11] selftests/damon/sysfs.sh: test multiple probe dirs creation SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 06/11] selftests/damon/sysfs.sh: test dests dir SeongJae Park
                   ` (5 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Shuah Khan, damon, linux-kernel, linux-kselftest,
	linux-mm

DAMON sysfs interface essential file operations test (sysf.sh) is not
testing DAMOS {core,ops}_filters directories.  Add the tests.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/sysfs.sh | 28 ++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/damon/sysfs.sh b/tools/testing/selftests/damon/sysfs.sh
index d528dfea44c3b..78eea0d13c271 100755
--- a/tools/testing/selftests/damon/sysfs.sh
+++ b/tools/testing/selftests/damon/sysfs.sh
@@ -103,10 +103,28 @@ test_filter()
 {
 	filter_dir=$1
 	ensure_file "$filter_dir/type" "exist" "600"
-	ensure_write_succ "$filter_dir/type" "anon" "valid input"
-	ensure_write_succ "$filter_dir/type" "memcg" "valid input"
-	ensure_write_succ "$filter_dir/type" "addr" "valid input"
-	ensure_write_succ "$filter_dir/type" "target" "valid input"
+
+	local dir_name=$(basename "$(dirname "$filter_dir")")
+	if  [ "$dir_name" = "filters" ] || [ "$dir_name" = "ops_filters" ]
+	then
+		ensure_write_succ "$filter_dir/type" "anon" "valid input"
+		ensure_write_succ "$filter_dir/type" "memcg" "valid input"
+	fi
+	if  [ "$dir_name" = "filters" ] || [ "$dir_name" = "core_filters" ]
+	then
+		ensure_write_succ "$filter_dir/type" "addr" "valid input"
+		ensure_write_succ "$filter_dir/type" "target" "valid input"
+	fi
+	if [ "$dir_name" = "core_filters" ]
+	then
+		ensure_write_fail "$filter_dir/type" "anon" "ops type"
+		ensure_write_fail "$filter_dir/type" "memcg" "ops type"
+	fi
+	if [ "$dir_name"  = "ops_filters" ]
+	then
+		ensure_write_fail "$filter_dir/type" "addr" "core type"
+		ensure_write_fail "$filter_dir/type" "target" "core type"
+	fi
 	ensure_write_fail "$filter_dir/type" "foo" "invalid input"
 	ensure_file "$filter_dir/matching" "exist" "600"
 	ensure_file "$filter_dir/memcg_path" "exist" "600"
@@ -208,6 +226,8 @@ test_scheme()
 	test_quotas "$scheme_dir/quotas"
 	test_watermarks "$scheme_dir/watermarks"
 	test_filters "$scheme_dir/filters"
+	test_filters "$scheme_dir/core_filters"
+	test_filters "$scheme_dir/ops_filters"
 	test_stats "$scheme_dir/stats"
 	test_tried_regions "$scheme_dir/tried_regions"
 }
-- 
2.47.3

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 06/11] selftests/damon/sysfs.sh: test dests dir
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (4 preceding siblings ...)
  2026-06-24 14:20 ` [RFC PATCH 05/11] selftests/damon/sysfs.sh: test {core,ops}_filters/ directories SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 07/11] selftests/damon/sysfs.sh: test all files in quota goal dir SeongJae Park
                   ` (4 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Shuah Khan, damon, linux-kernel, linux-kselftest,
	linux-mm

DAMON selftest interface essential file operations test (sysfs.sh) is
not testing DAMOS dests/ directory.  Add the test.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/sysfs.sh | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/tools/testing/selftests/damon/sysfs.sh b/tools/testing/selftests/damon/sysfs.sh
index 78eea0d13c271..cbfababa0bf31 100755
--- a/tools/testing/selftests/damon/sysfs.sh
+++ b/tools/testing/selftests/damon/sysfs.sh
@@ -99,6 +99,29 @@ test_stats()
 	done
 }
 
+test_dest()
+{
+	dest_dir=$1
+	ensure_file "$dest_dir/id" "exist"
+	ensure_file "$dest_dir/weight" "exist"
+}
+
+test_dests()
+{
+	dests_dir=$1
+	ensure_file "$dests_dir/nr_dests" "exist" "600"
+	ensure_write_succ "$dests_dir/nr_dests" "1" "valid input"
+	test_dest "$dests_dir/0"
+
+	ensure_write_succ "$dests_dir/nr_dests" "2" "valid input"
+	test_dest "$dests_dir/0"
+	test_dest "$dests_dir/1"
+
+	ensure_write_succ "$dests_dir/nr_dests" "0" "valid input"
+	ensure_dir "$dests_dir/0" "not_exist"
+	ensure_dir "$dests_dir/1" "not_exist"
+}
+
 test_filter()
 {
 	filter_dir=$1
-- 
2.47.3

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 07/11] selftests/damon/sysfs.sh: test all files in quota goal dir
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (5 preceding siblings ...)
  2026-06-24 14:20 ` [RFC PATCH 06/11] selftests/damon/sysfs.sh: test dests dir SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 08/11] mm/damon/core: reduce range setup in damon_commit_target_regions() SeongJae Park
                   ` (3 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Shuah Khan, damon, linux-kernel, linux-kselftest,
	linux-mm

DAMON sysfs interface for DAMOS quota has quite extended since its
initial introduction.  The test case for that in DAMON sysfs interface
essential file operations test (sysfs.sh) has not accordingly extended,
though.  Extend the test case to test all existing files.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/sysfs.sh | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tools/testing/selftests/damon/sysfs.sh b/tools/testing/selftests/damon/sysfs.sh
index cbfababa0bf31..ad3aab240b360 100755
--- a/tools/testing/selftests/damon/sysfs.sh
+++ b/tools/testing/selftests/damon/sysfs.sh
@@ -199,6 +199,20 @@ test_goal()
 	ensure_dir "$goal_dir" "exist"
 	ensure_file "$goal_dir/target_value" "exist" "600"
 	ensure_file "$goal_dir/current_value" "exist" "600"
+	ensure_file "$goal_dir/target_metric" "exist" "600"
+	local fpath="$goal_dir/target_metric"
+	ensure_write_succ "$fpath" "user_input" "valid input"
+	ensure_write_succ "$fpath" "some_mem_psi_us" "valid input"
+	ensure_write_succ "$fpath" "node_mem_used_bp" "valid input"
+	ensure_write_succ "$fpath" "node_mem_free_bp" "valid input"
+	ensure_write_succ "$fpath" "node_memcg_used_bp" "valid input"
+	ensure_write_succ "$fpath" "node_memcg_free_bp" "valid input"
+	ensure_write_succ "$fpath" "active_mem_bp" "valid input"
+	ensure_write_succ "$fpath" "inactive_mem_bp" "valid input"
+	ensure_write_succ "$fpath" "node_eligible_mem_bp" "valid input"
+	ensure_write_fail "$fpath" "foo" "invalid input"
+	ensure_file "$goal_dir/nid" "exist" "600"
+	ensure_file "$goal_dir/path" "exist" "600"
 }
 
 test_goals()
-- 
2.47.3

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 08/11] mm/damon/core: reduce range setup in damon_commit_target_regions()
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (6 preceding siblings ...)
  2026-06-24 14:20 ` [RFC PATCH 07/11] selftests/damon/sysfs.sh: test all files in quota goal dir SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 09/11] mm/damon/sysfs: split probe setup function out SeongJae Park
                   ` (2 subsequent siblings)
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Andrew Morton, damon, linux-kernel, linux-mm

damon_commit_target_regions() calls damon_set_regions() for updating the
destination target's monitoring target region boundaries.  It sets the
boundaries same to source target's monitoring regions, even if they are
adjacent.  Meanwhile, damon_set_region() sets the destination target
regions exactly the same to the source, only when the target regions are
empty.  When there are existing target regions, only a few regions are
expanded or shrunk to fit on only the boundaries for disjoint regions in
the source.  Hence the adjacent source ranges mean nothing in common
cases.  When there are many regions, such adjacent range setup is only a
waste of time and space.  We recently found [1] it is actually causing
memory overhead.  Setup the ranges for only distinct ranges.

[1] https://lore.kernel.org/20260603112306.58490-1-akinobu.mita@gmail.com

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/core.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/mm/damon/core.c b/mm/damon/core.c
index b5f63f2f726be..10deab847ee71 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -1433,21 +1433,33 @@ static struct damon_target *damon_nth_target(int n, struct damon_ctx *ctx)
 static int damon_commit_target_regions(struct damon_target *dst,
 		struct damon_target *src, unsigned long src_min_region_sz)
 {
-	struct damon_region *src_region;
+	struct damon_region *src_region, *prev = NULL;
 	struct damon_addr_range *ranges;
 	int i = 0, err;
 
-	damon_for_each_region(src_region, src)
-		i++;
+	damon_for_each_region(src_region, src) {
+		if (!prev || prev->ar.end != src_region->ar.start)
+			i++;
+		prev = src_region;
+	}
 	if (!i)
 		return 0;
 
 	ranges = kvmalloc_objs(*ranges, i, GFP_KERNEL | __GFP_NOWARN);
 	if (!ranges)
 		return -ENOMEM;
+	prev = NULL;
 	i = 0;
-	damon_for_each_region(src_region, src)
-		ranges[i++] = src_region->ar;
+	damon_for_each_region(src_region, src) {
+		if (!prev) {
+			ranges[i].start = src_region->ar.start;
+		} else if (prev->ar.end != src_region->ar.start) {
+			ranges[i++].end = prev->ar.end;
+			ranges[i].start = src_region->ar.start;
+		}
+		prev = src_region;
+	}
+	ranges[i++].end = damon_last_region(src)->ar.end;
 	err = damon_set_regions(dst, ranges, i, src_min_region_sz);
 	kvfree(ranges);
 	return err;
-- 
2.47.3

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 09/11] mm/damon/sysfs: split probe setup function out
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (7 preceding siblings ...)
  2026-06-24 14:20 ` [RFC PATCH 08/11] mm/damon/core: reduce range setup in damon_commit_target_regions() SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 10/11] mm/damon/sysfs: split out filters setup function SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 11/11] mm/damon/sysfs: fix typos in probe_{add,rm}_dirs: s/attr/probe/ SeongJae Park
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Andrew Morton, damon, linux-kernel, linux-mm

damon_sysfs_set_probes() function is relatively long.  It has two nested
loop for setting two nested entities, namely probe and filter.  Split
out the probe level setup for readability.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs.c | 80 ++++++++++++++++++++++++++++--------------------
 1 file changed, 46 insertions(+), 34 deletions(-)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index ffbc99411f53b..b662afd41791d 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1911,47 +1911,59 @@ static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
 	return damon_set_attrs(ctx, &attrs);
 }
 
-static int damon_sysfs_set_probes(struct damon_ctx *ctx,
-		struct damon_sysfs_probes *sys_probes)
+static int damon_sysfs_set_probe(struct damon_probe *probe,
+		struct damon_sysfs_probe *sys_probe)
 {
+	struct damon_sysfs_filters *sys_filters;
 	int i;
 
-	for (i = 0; i < sys_probes->nr; i++) {
-		struct damon_sysfs_filters *sys_filters =
-			sys_probes->probes_arr[i]->filters;
-		struct damon_probe *c;
-		int j;
+	sys_filters = sys_probe->filters;
+	if (!sys_filters)
+		return 0;
 
-		if (!sys_filters)
-			continue;
-		c = damon_new_probe();
-		if (!c)
+	for (i = 0; i < sys_filters->nr; i++) {
+		struct damon_sysfs_filter *sys_filter =
+			sys_filters->filters_arr[i];
+		struct damon_filter *filter;
+
+		filter = damon_new_filter(sys_filter->type,
+				sys_filter->matching,
+				sys_filter->allow);
+		if (!filter)
 			return -ENOMEM;
-		damon_add_probe(ctx, c);
-
-		for (j = 0; j < sys_filters->nr; j++) {
-			struct damon_sysfs_filter *sys_filter =
-				sys_filters->filters_arr[j];
-			struct damon_filter *filter;
-
-			filter = damon_new_filter(sys_filter->type,
-					sys_filter->matching,
-					sys_filter->allow);
-			if (!filter)
-				return -ENOMEM;
-			if (filter->type == DAMON_FILTER_TYPE_MEMCG) {
-				int err;
-
-				err = damon_sysfs_memcg_path_to_id(
-						sys_filter->path,
-						&filter->memcg_id);
-				if (err) {
-					damon_destroy_filter(filter);
-					return err;
-				}
+		if (filter->type == DAMON_FILTER_TYPE_MEMCG) {
+			int err;
+
+			err = damon_sysfs_memcg_path_to_id(
+					sys_filter->path,
+					&filter->memcg_id);
+			if (err) {
+				damon_destroy_filter(filter);
+				return err;
 			}
-			damon_add_filter(c, filter);
 		}
+		damon_add_filter(probe, filter);
+	}
+	return 0;
+}
+
+static int damon_sysfs_set_probes(struct damon_ctx *ctx,
+		struct damon_sysfs_probes *sys_probes)
+{
+	int i, err;
+
+	for (i = 0; i < sys_probes->nr; i++) {
+		struct damon_sysfs_probe *sys_probe;
+		struct damon_probe *p;
+
+		p = damon_new_probe();
+		if (!p)
+			return -ENOMEM;
+		damon_add_probe(ctx, p);
+		sys_probe = sys_probes->probes_arr[i];
+		err = damon_sysfs_set_probe(p, sys_probe);
+		if (err)
+			return err;
 	}
 	return 0;
 }
-- 
2.47.3

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 10/11] mm/damon/sysfs: split out filters setup function
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (8 preceding siblings ...)
  2026-06-24 14:20 ` [RFC PATCH 09/11] mm/damon/sysfs: split probe setup function out SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  2026-06-24 14:20 ` [RFC PATCH 11/11] mm/damon/sysfs: fix typos in probe_{add,rm}_dirs: s/attr/probe/ SeongJae Park
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Andrew Morton, damon, linux-kernel, linux-mm

damon_sysfs_set_probe() is doing not only probe setup but also filters
setup.  Split out filters setup for readability.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index b662afd41791d..92de341827cab 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1911,16 +1911,11 @@ static int damon_sysfs_set_attrs(struct damon_ctx *ctx,
 	return damon_set_attrs(ctx, &attrs);
 }
 
-static int damon_sysfs_set_probe(struct damon_probe *probe,
-		struct damon_sysfs_probe *sys_probe)
+static int damon_sysfs_set_filters(struct damon_probe *probe,
+		struct damon_sysfs_filters *sys_filters)
 {
-	struct damon_sysfs_filters *sys_filters;
 	int i;
 
-	sys_filters = sys_probe->filters;
-	if (!sys_filters)
-		return 0;
-
 	for (i = 0; i < sys_filters->nr; i++) {
 		struct damon_sysfs_filter *sys_filter =
 			sys_filters->filters_arr[i];
@@ -1947,6 +1942,17 @@ static int damon_sysfs_set_probe(struct damon_probe *probe,
 	return 0;
 }
 
+static int damon_sysfs_set_probe(struct damon_probe *probe,
+		struct damon_sysfs_probe *sys_probe)
+{
+	struct damon_sysfs_filters *sys_filters;
+
+	sys_filters = sys_probe->filters;
+	if (!sys_filters)
+		return 0;
+	return damon_sysfs_set_filters(probe, sys_filters);
+}
+
 static int damon_sysfs_set_probes(struct damon_ctx *ctx,
 		struct damon_sysfs_probes *sys_probes)
 {
-- 
2.47.3

^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [RFC PATCH 11/11] mm/damon/sysfs: fix typos in probe_{add,rm}_dirs: s/attr/probe/
  2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
                   ` (9 preceding siblings ...)
  2026-06-24 14:20 ` [RFC PATCH 10/11] mm/damon/sysfs: split out filters setup function SeongJae Park
@ 2026-06-24 14:20 ` SeongJae Park
  10 siblings, 0 replies; 12+ messages in thread
From: SeongJae Park @ 2026-06-24 14:20 UTC (permalink / raw)
  Cc: SeongJae Park, Andrew Morton, damon, linux-kernel, linux-mm

damon_sysfs_probe_{add,rm}_dirs names a variable for damon_sysf_probe
as 'attr'.  Probably a trivial copy-pasta error, but it makes the code
not pleasant to read.  Fix those.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/sysfs.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 92de341827cab..9f9262c9b99ba 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -1075,7 +1075,7 @@ static struct damon_sysfs_probe *damon_sysfs_probe_alloc(void)
 	return kzalloc_obj(struct damon_sysfs_probe);
 }
 
-static int damon_sysfs_probe_add_dirs(struct damon_sysfs_probe *attr)
+static int damon_sysfs_probe_add_dirs(struct damon_sysfs_probe *probe)
 {
 	struct damon_sysfs_filters *filters;
 	int err;
@@ -1083,22 +1083,22 @@ static int damon_sysfs_probe_add_dirs(struct damon_sysfs_probe *attr)
 	filters = damon_sysfs_filters_alloc();
 	if (!filters)
 		return -ENOMEM;
-	attr->filters = filters;
+	probe->filters = filters;
 
 	err = kobject_init_and_add(&filters->kobj, &damon_sysfs_filters_ktype,
-			&attr->kobj, "filters");
+			&probe->kobj, "filters");
 	if (err) {
 		kobject_put(&filters->kobj);
-		attr->filters = NULL;
+		probe->filters = NULL;
 	}
 	return err;
 }
 
-static void damon_sysfs_probe_rm_dirs(struct damon_sysfs_probe *attr)
+static void damon_sysfs_probe_rm_dirs(struct damon_sysfs_probe *probe)
 {
-	if (attr->filters) {
-		damon_sysfs_filters_rm_dirs(attr->filters);
-		kobject_put(&attr->filters->kobj);
+	if (probe->filters) {
+		damon_sysfs_filters_rm_dirs(probe->filters);
+		kobject_put(&probe->filters->kobj);
 	}
 }
 
-- 
2.47.3

^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2026-06-24 14:20 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-06-24 14:19 [RFC PATCH 00/11] mm/damon: update, optimize, and clean up doc, tests, and code SeongJae Park
2026-06-24 14:19 ` [RFC PATCH 01/11] Docs/mm/damon/design: update for DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP SeongJae Park
2026-06-24 14:19 ` [RFC PATCH 02/11] Docs/ABI/damon: document probe files SeongJae Park
2026-06-24 14:19 ` [RFC PATCH 03/11] mm/damon/tests/core-kunit: test damon_rand() SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 04/11] selftests/damon/sysfs.sh: test multiple probe dirs creation SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 05/11] selftests/damon/sysfs.sh: test {core,ops}_filters/ directories SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 06/11] selftests/damon/sysfs.sh: test dests dir SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 07/11] selftests/damon/sysfs.sh: test all files in quota goal dir SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 08/11] mm/damon/core: reduce range setup in damon_commit_target_regions() SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 09/11] mm/damon/sysfs: split probe setup function out SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 10/11] mm/damon/sysfs: split out filters setup function SeongJae Park
2026-06-24 14:20 ` [RFC PATCH 11/11] mm/damon/sysfs: fix typos in probe_{add,rm}_dirs: s/attr/probe/ SeongJae Park

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.