[RFC PATCH 0/7] mm/damon: remove DAMON debugfs interface

[RFC PATCH 0/7] mm/damon: remove DAMON debugfs interface

[SeongJae Park]

DAMON debugfs interface was the only user interface of DAMON at the
beginning[1].  However, it turned out the interface would be not good
enough for long-term flexibility and stability.

In Feb 2022[2], we therefore introduced DAMON sysfs interface as an
alternative user interface that aims long-term flexibility and
stability.  With its introduction, DAMON debugfs interface has announced
to be deprecated in near future.

In Feb 2023[3], we announced the official deprecation of DAMON debugfs
interface.  In Jan 2024[4], we further made the deprecation difficult to
be ignored.

And as of this writing (2024-10-14), no problem or concerns about the
deprecation have reported.  Apparently users are already moved to the
alternative, or made good plans for the change.

Remove the DAMON debugfs interface code from the tree.  Given the past
timeline and the absence of reported problems or concerns, it is safe
enough to be done.  That said, we will not drop the RFC tag of this
patch series at least until the end of this year, to use this as the
real last call for users.

[1] https://lore.kernel.org/20210716081449.22187-1-sj38.park@gmail.com
[2] https://lore.kernel.org/20220228081314.5770-1-sj@kernel.org
[3] https://lore.kernel.org/20230209192009.7885-1-sj@kernel.org
[4] https://lore.kernel.org/20240130013549.89538-1-sj@kernel.org

SeongJae Park (7):
  Docs/admin-guide/mm/damon/usage: remove DAMON debugfs interface
    documentation
  Docs/mm/damon/design: update for removal of DAMON debugfs interface
  selftests/damon/config: remove configs for DAMON debugfs interface
    selftests
  selftests/damon: remove tests for DAMON debugfs interface
  kunit: configs: remove configs for DAMON debugfs interface tests
  mm/damon: remove DAMON debugfs interface kunit tests
  mm/damon: remove DAMON debugfs interface

 Documentation/admin-guide/mm/damon/usage.rst  |  309 -----
 Documentation/mm/damon/design.rst             |   23 +-
 mm/damon/Kconfig                              |   30 -
 mm/damon/Makefile                             |    1 -
 mm/damon/dbgfs.c                              | 1148 -----------------
 mm/damon/tests/.kunitconfig                   |    7 -
 mm/damon/tests/dbgfs-kunit.h                  |  173 ---
 tools/testing/kunit/configs/all_tests.config  |    3 -
 tools/testing/selftests/damon/.gitignore      |    3 -
 tools/testing/selftests/damon/Makefile        |   11 +-
 tools/testing/selftests/damon/config          |    1 -
 .../testing/selftests/damon/debugfs_attrs.sh  |   17 -
 .../debugfs_duplicate_context_creation.sh     |   27 -
 .../selftests/damon/debugfs_empty_targets.sh  |   21 -
 .../damon/debugfs_huge_count_read_write.sh    |   22 -
 .../damon/debugfs_rm_non_contexts.sh          |   19 -
 .../selftests/damon/debugfs_schemes.sh        |   19 -
 .../selftests/damon/debugfs_target_ids.sh     |   19 -
 .../damon/debugfs_target_ids_pid_leak.c       |   68 -
 .../damon/debugfs_target_ids_pid_leak.sh      |   22 -
 ...fs_target_ids_read_before_terminate_race.c |   80 --
 ...s_target_ids_read_before_terminate_race.sh |   14 -
 .../selftests/damon/huge_count_read_write.c   |   48 -
 23 files changed, 11 insertions(+), 2074 deletions(-)
 delete mode 100644 mm/damon/dbgfs.c
 delete mode 100644 mm/damon/tests/dbgfs-kunit.h
 delete mode 100755 tools/testing/selftests/damon/debugfs_attrs.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_duplicate_context_creation.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_empty_targets.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_huge_count_read_write.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_rm_non_contexts.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_schemes.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_target_ids.sh
 delete mode 100644 tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c
 delete mode 100755 tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh
 delete mode 100644 tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.c
 delete mode 100755 tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.sh
 delete mode 100644 tools/testing/selftests/damon/huge_count_read_write.c


base-commit: 5ef943709a1b88304aa6e8cb8683a25bf81874f0
-- 
2.39.5

[RFC PATCH 3/7] selftests/damon/config: remove configs for DAMON debugfs interface selftests

[SeongJae Park]

It's time to remove DAMON debugfs interface, which has deprecated long
before in February 2023.  Read the cover letter of this patch series for
more details.

Remove configs for selftests of it from DAMON selftests config file, to
prevent unnecessary noises from the tests.

[1] https://lore.kernel.org/20230209192009.7885-1-sj@kernel.org

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/config | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/testing/selftests/damon/config b/tools/testing/selftests/damon/config
index 0daf38974eb0..a68a9fead5dc 100644
--- a/tools/testing/selftests/damon/config
+++ b/tools/testing/selftests/damon/config
@@ -1,6 +1,5 @@
 CONFIG_DAMON=y
 CONFIG_DAMON_SYSFS=y
-CONFIG_DAMON_DBGFS=y
 CONFIG_DAMON_PADDR=y
 CONFIG_DAMON_VADDR=y
 CONFIG_DAMON_RECLAIM=y
-- 
2.39.5

[RFC PATCH 4/7] selftests/damon: remove tests for DAMON debugfs interface

[SeongJae Park]

It's time to remove DAMON debugfs interface, which has deprecated long
before in February 2023.  Read the cover letter of this patch series for
more details.

Remove selftests for the interface, to prevent causing unnecessary test
failures.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/.gitignore      |  3 -
 tools/testing/selftests/damon/Makefile        | 11 +--
 .../testing/selftests/damon/debugfs_attrs.sh  | 17 ----
 .../debugfs_duplicate_context_creation.sh     | 27 -------
 .../selftests/damon/debugfs_empty_targets.sh  | 21 -----
 .../damon/debugfs_huge_count_read_write.sh    | 22 -----
 .../damon/debugfs_rm_non_contexts.sh          | 19 -----
 .../selftests/damon/debugfs_schemes.sh        | 19 -----
 .../selftests/damon/debugfs_target_ids.sh     | 19 -----
 .../damon/debugfs_target_ids_pid_leak.c       | 68 ----------------
 .../damon/debugfs_target_ids_pid_leak.sh      | 22 -----
 ...fs_target_ids_read_before_terminate_race.c | 80 -------------------
 ...s_target_ids_read_before_terminate_race.sh | 14 ----
 .../selftests/damon/huge_count_read_write.c   | 48 -----------
 14 files changed, 1 insertion(+), 389 deletions(-)
 delete mode 100755 tools/testing/selftests/damon/debugfs_attrs.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_duplicate_context_creation.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_empty_targets.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_huge_count_read_write.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_rm_non_contexts.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_schemes.sh
 delete mode 100755 tools/testing/selftests/damon/debugfs_target_ids.sh
 delete mode 100644 tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c
 delete mode 100755 tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh
 delete mode 100644 tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.c
 delete mode 100755 tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.sh
 delete mode 100644 tools/testing/selftests/damon/huge_count_read_write.c

diff --git a/tools/testing/selftests/damon/.gitignore b/tools/testing/selftests/damon/.gitignore
index 2ab675fecb6b..2f0297657c81 100644
--- a/tools/testing/selftests/damon/.gitignore
+++ b/tools/testing/selftests/damon/.gitignore
@@ -1,6 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
-huge_count_read_write
-debugfs_target_ids_read_before_terminate_race
-debugfs_target_ids_pid_leak
 access_memory
 access_memory_even
diff --git a/tools/testing/selftests/damon/Makefile b/tools/testing/selftests/damon/Makefile
index 5b2a6a5dd1af..fa6042998004 100644
--- a/tools/testing/selftests/damon/Makefile
+++ b/tools/testing/selftests/damon/Makefile
@@ -1,15 +1,11 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for damon selftests
 
-TEST_GEN_FILES += huge_count_read_write
-TEST_GEN_FILES += debugfs_target_ids_read_before_terminate_race
-TEST_GEN_FILES += debugfs_target_ids_pid_leak
 TEST_GEN_FILES += access_memory access_memory_even
 
-TEST_FILES = _chk_dependency.sh _debugfs_common.sh
+TEST_FILES = _chk_dependency.sh
 
 # functionality tests
-TEST_PROGS = debugfs_attrs.sh debugfs_schemes.sh debugfs_target_ids.sh
 TEST_PROGS += sysfs.sh
 TEST_PROGS += sysfs_update_schemes_tried_regions_wss_estimation.py
 TEST_PROGS += damos_quota.py damos_quota_goal.py damos_apply_interval.py
@@ -17,11 +13,6 @@ TEST_PROGS += damos_tried_regions.py damon_nr_regions.py
 TEST_PROGS += reclaim.sh lru_sort.sh
 
 # regression tests (reproducers of previously found bugs)
-TEST_PROGS += debugfs_empty_targets.sh debugfs_huge_count_read_write.sh
-TEST_PROGS += debugfs_duplicate_context_creation.sh
-TEST_PROGS += debugfs_rm_non_contexts.sh
-TEST_PROGS += debugfs_target_ids_read_before_terminate_race.sh
-TEST_PROGS += debugfs_target_ids_pid_leak.sh
 TEST_PROGS += sysfs_update_removed_scheme_dir.sh
 TEST_PROGS += sysfs_update_schemes_tried_regions_hang.py
 
diff --git a/tools/testing/selftests/damon/debugfs_attrs.sh b/tools/testing/selftests/damon/debugfs_attrs.sh
deleted file mode 100755
index 902e312bca89..000000000000
--- a/tools/testing/selftests/damon/debugfs_attrs.sh
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-source _debugfs_common.sh
-
-# Test attrs file
-# ===============
-
-file="$DBGFS/attrs"
-orig_content=$(cat "$file")
-
-test_write_succ "$file" "1 2 3 4 5" "$orig_content" "valid input"
-test_write_fail "$file" "1 2 3 4" "$orig_content" "no enough fields"
-test_write_fail "$file" "1 2 3 5 4" "$orig_content" \
-	"min_nr_regions > max_nr_regions"
-test_content "$file" "$orig_content" "1 2 3 4 5" "successfully written"
-echo "$orig_content" > "$file"
diff --git a/tools/testing/selftests/damon/debugfs_duplicate_context_creation.sh b/tools/testing/selftests/damon/debugfs_duplicate_context_creation.sh
deleted file mode 100755
index 4a76e37ef16b..000000000000
--- a/tools/testing/selftests/damon/debugfs_duplicate_context_creation.sh
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-source _debugfs_common.sh
-
-# Test duplicated context creation
-# ================================
-
-if ! echo foo > "$DBGFS/mk_contexts"
-then
-	echo "context creation failed"
-	exit 1
-fi
-
-if echo foo > "$DBGFS/mk_contexts"
-then
-	echo "duplicate context creation success"
-	exit 1
-fi
-
-if ! echo foo > "$DBGFS/rm_contexts"
-then
-	echo "context deletion failed"
-	exit 1
-fi
-
-exit 0
diff --git a/tools/testing/selftests/damon/debugfs_empty_targets.sh b/tools/testing/selftests/damon/debugfs_empty_targets.sh
deleted file mode 100755
index effbea33dc16..000000000000
--- a/tools/testing/selftests/damon/debugfs_empty_targets.sh
+++ /dev/null
@@ -1,21 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-source _debugfs_common.sh
-
-# Test empty targets case
-# =======================
-
-orig_target_ids=$(cat "$DBGFS/target_ids")
-echo "" > "$DBGFS/target_ids"
-
-if [ -f "$DBGFS/monitor_on_DEPRECATED" ]
-then
-	monitor_on_file="$DBGFS/monitor_on_DEPRECATED"
-else
-	monitor_on_file="$DBGFS/monitor_on"
-fi
-
-orig_monitor_on=$(cat "$monitor_on_file")
-test_write_fail "$monitor_on_file" "on" "orig_monitor_on" "empty target ids"
-echo "$orig_target_ids" > "$DBGFS/target_ids"
diff --git a/tools/testing/selftests/damon/debugfs_huge_count_read_write.sh b/tools/testing/selftests/damon/debugfs_huge_count_read_write.sh
deleted file mode 100755
index 922cadac2950..000000000000
--- a/tools/testing/selftests/damon/debugfs_huge_count_read_write.sh
+++ /dev/null
@@ -1,22 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-source _debugfs_common.sh
-
-# Test huge count read write
-# ==========================
-
-dmesg -C
-
-for file in "$DBGFS/"*
-do
-	./huge_count_read_write "$file"
-done
-
-if dmesg | grep -q WARNING
-then
-	dmesg
-	exit 1
-else
-	exit 0
-fi
diff --git a/tools/testing/selftests/damon/debugfs_rm_non_contexts.sh b/tools/testing/selftests/damon/debugfs_rm_non_contexts.sh
deleted file mode 100755
index f3ffeb1343cf..000000000000
--- a/tools/testing/selftests/damon/debugfs_rm_non_contexts.sh
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-source _debugfs_common.sh
-
-# Test putting non-ctx files/dirs to rm_contexts file
-# ===================================================
-
-dmesg -C
-
-for file in "$DBGFS/"*
-do
-	(echo "$(basename "$f")" > "$DBGFS/rm_contexts") &> /dev/null
-	if dmesg | grep -q BUG
-	then
-		dmesg
-		exit 1
-	fi
-done
diff --git a/tools/testing/selftests/damon/debugfs_schemes.sh b/tools/testing/selftests/damon/debugfs_schemes.sh
deleted file mode 100755
index 5b39ab44731c..000000000000
--- a/tools/testing/selftests/damon/debugfs_schemes.sh
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-source _debugfs_common.sh
-
-# Test schemes file
-# =================
-
-file="$DBGFS/schemes"
-orig_content=$(cat "$file")
-
-test_write_succ "$file" "1 2 3 4 5 6 4 0 0 0 1 2 3 1 100 3 2 1" \
-	"$orig_content" "valid input"
-test_write_fail "$file" "1 2
-3 4 5 6 3 0 0 0 1 2 3 1 100 3 2 1" "$orig_content" "multi lines"
-test_write_succ "$file" "" "$orig_content" "disabling"
-test_write_fail "$file" "2 1 2 1 10 1 3 10 1 1 1 1 1 1 1 1 2 3" \
-	"$orig_content" "wrong condition ranges"
-echo "$orig_content" > "$file"
diff --git a/tools/testing/selftests/damon/debugfs_target_ids.sh b/tools/testing/selftests/damon/debugfs_target_ids.sh
deleted file mode 100755
index 49aeabdb0aae..000000000000
--- a/tools/testing/selftests/damon/debugfs_target_ids.sh
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-source _debugfs_common.sh
-
-# Test target_ids file
-# ====================
-
-file="$DBGFS/target_ids"
-orig_content=$(cat "$file")
-
-test_write_succ "$file" "1 2 3 4" "$orig_content" "valid input"
-test_write_succ "$file" "1 2 abc 4" "$orig_content" "still valid input"
-test_content "$file" "$orig_content" "1 2" "non-integer was there"
-test_write_succ "$file" "abc 2 3" "$orig_content" "the file allows wrong input"
-test_content "$file" "$orig_content" "" "wrong input written"
-test_write_succ "$file" "" "$orig_content" "empty input"
-test_content "$file" "$orig_content" "" "empty input written"
-echo "$orig_content" > "$file"
diff --git a/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c b/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c
deleted file mode 100644
index 0cc2eef7d142..000000000000
--- a/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.c
+++ /dev/null
@@ -1,68 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Author: SeongJae Park <sj@kernel.org>
- */
-
-#define _GNU_SOURCE
-
-#include <fcntl.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sys/time.h>
-#include <unistd.h>
-
-#define DBGFS_TARGET_IDS "/sys/kernel/debug/damon/target_ids"
-
-static void write_targetid_exit(void)
-{
-	int target_ids_fd = open(DBGFS_TARGET_IDS, O_RDWR);
-	char pid_str[128];
-
-	snprintf(pid_str, sizeof(pid_str), "%d", getpid());
-	write(target_ids_fd, pid_str, sizeof(pid_str));
-	close(target_ids_fd);
-	exit(0);
-}
-
-unsigned long msec_timestamp(void)
-{
-	struct timeval tv;
-
-	gettimeofday(&tv, NULL);
-	return tv.tv_sec * 1000UL + tv.tv_usec / 1000;
-}
-
-int main(int argc, char *argv[])
-{
-	unsigned long start_ms;
-	int time_to_run, nr_forks = 0;
-
-	if (argc != 2) {
-		fprintf(stderr, "Usage: %s <msecs to run>\n", argv[0]);
-		exit(1);
-	}
-	time_to_run = atoi(argv[1]);
-
-	start_ms = msec_timestamp();
-	while (true) {
-		int pid = fork();
-
-		if (pid < 0) {
-			fprintf(stderr, "fork() failed\n");
-			exit(1);
-		}
-		if (pid == 0)
-			write_targetid_exit();
-		wait(NULL);
-		nr_forks++;
-
-		if (msec_timestamp() - start_ms > time_to_run)
-			break;
-	}
-	printf("%d\n", nr_forks);
-	return 0;
-}
diff --git a/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh b/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh
deleted file mode 100755
index 31fe33c2b032..000000000000
--- a/tools/testing/selftests/damon/debugfs_target_ids_pid_leak.sh
+++ /dev/null
@@ -1,22 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-before=$(grep "^pid " /proc/slabinfo | awk '{print $2}')
-
-nr_leaks=$(./debugfs_target_ids_pid_leak 1000)
-expected_after_max=$((before + nr_leaks / 2))
-
-after=$(grep "^pid " /proc/slabinfo | awk '{print $2}')
-
-echo > /sys/kernel/debug/damon/target_ids
-
-echo "tried $nr_leaks pid leak"
-echo "number of active pid slabs: $before -> $after"
-echo "(up to $expected_after_max expected)"
-if [ $after -gt $expected_after_max ]
-then
-	echo "maybe pids are leaking"
-	exit 1
-else
-	exit 0
-fi
diff --git a/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.c b/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.c
deleted file mode 100644
index b06f52a8ce2d..000000000000
--- a/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.c
+++ /dev/null
@@ -1,80 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Author: SeongJae Park <sj@kernel.org>
- */
-#define _GNU_SOURCE
-
-#include <fcntl.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <time.h>
-#include <unistd.h>
-
-#define DBGFS_MONITOR_ON "/sys/kernel/debug/damon/monitor_on_DEPRECATED"
-#define DBGFS_TARGET_IDS "/sys/kernel/debug/damon/target_ids"
-
-static void turn_damon_on_exit(void)
-{
-	int target_ids_fd = open(DBGFS_TARGET_IDS, O_RDWR);
-	int monitor_on_fd = open(DBGFS_MONITOR_ON, O_RDWR);
-	char pid_str[128];
-
-	snprintf(pid_str, sizeof(pid_str), "%d", getpid());
-	write(target_ids_fd, pid_str, sizeof(pid_str));
-	write(monitor_on_fd, "on\n", 3);
-	close(target_ids_fd);
-	close(monitor_on_fd);
-	usleep(1000);
-	exit(0);
-}
-
-static void try_race(void)
-{
-	int target_ids_fd = open(DBGFS_TARGET_IDS, O_RDWR);
-	int pid = fork();
-	int buf[256];
-
-	if (pid < 0) {
-		fprintf(stderr, "fork() failed\n");
-		exit(1);
-	}
-	if (pid == 0)
-		turn_damon_on_exit();
-	while (true) {
-		int status;
-
-		read(target_ids_fd, buf, sizeof(buf));
-		if (waitpid(-1, &status, WNOHANG) == pid)
-			break;
-	}
-	close(target_ids_fd);
-}
-
-static inline uint64_t ts_to_ms(struct timespec *ts)
-{
-	return (uint64_t)ts->tv_sec * 1000 + (uint64_t)ts->tv_nsec / 1000000;
-}
-
-int main(int argc, char *argv[])
-{
-	struct timespec start_time, now;
-	int runtime_ms;
-
-	if (argc != 2) {
-		fprintf(stderr, "Usage: %s <runtime in ms>\n", argv[0]);
-		exit(1);
-	}
-	runtime_ms = atoi(argv[1]);
-	clock_gettime(CLOCK_MONOTONIC, &start_time);
-	while (true) {
-		try_race();
-		clock_gettime(CLOCK_MONOTONIC, &now);
-		if (ts_to_ms(&now) - ts_to_ms(&start_time) > runtime_ms)
-			break;
-	}
-	return 0;
-}
diff --git a/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.sh b/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.sh
deleted file mode 100755
index fc793c4c9aea..000000000000
--- a/tools/testing/selftests/damon/debugfs_target_ids_read_before_terminate_race.sh
+++ /dev/null
@@ -1,14 +0,0 @@
-#!/bin/bash
-# SPDX-License-Identifier: GPL-2.0
-
-dmesg -C
-
-./debugfs_target_ids_read_before_terminate_race 5000
-
-if dmesg | grep -q dbgfs_target_ids_read
-then
-	dmesg
-	exit 1
-else
-	exit 0
-fi
diff --git a/tools/testing/selftests/damon/huge_count_read_write.c b/tools/testing/selftests/damon/huge_count_read_write.c
deleted file mode 100644
index a6fe0689f88d..000000000000
--- a/tools/testing/selftests/damon/huge_count_read_write.c
+++ /dev/null
@@ -1,48 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Author: SeongJae Park <sj@kernel.org>
- */
-
-#include <fcntl.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdio.h>
-
-#pragma GCC diagnostic push
-#if __GNUC__ >= 11 && __GNUC_MINOR__ >= 1
-/* Ignore read(2) overflow and write(2) overread compile warnings */
-#pragma GCC diagnostic ignored "-Wstringop-overread"
-#pragma GCC diagnostic ignored "-Wstringop-overflow"
-#endif
-
-void write_read_with_huge_count(char *file)
-{
-	int filedesc = open(file, O_RDWR);
-	char buf[25];
-	int ret;
-
-	printf("%s %s\n", __func__, file);
-	if (filedesc < 0) {
-		fprintf(stderr, "failed opening %s\n", file);
-		exit(1);
-	}
-
-	write(filedesc, "", 0xfffffffful);
-	perror("after write: ");
-	ret = read(filedesc, buf, 0xfffffffful);
-	perror("after read: ");
-	close(filedesc);
-}
-
-#pragma GCC diagnostic pop
-
-int main(int argc, char *argv[])
-{
-	if (argc != 2) {
-		fprintf(stderr, "Usage: %s <file>\n", argv[0]);
-		exit(1);
-	}
-	write_read_with_huge_count(argv[1]);
-
-	return 0;
-}
-- 
2.39.5

[RFC PATCH 5/7] kunit: configs: remove configs for DAMON debugfs interface tests

[SeongJae Park]

It's time to remove DAMON debugfs interface, which has deprecated long
before in February 2023.  Read the cover letter of this patch series for
more details.

Remove kernel configs for running DAMON debugfs interface kunit tests
from the kunit all_tests configuration, to prevent unnecessary noises
from tests.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/kunit/configs/all_tests.config | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/tools/testing/kunit/configs/all_tests.config b/tools/testing/kunit/configs/all_tests.config
index b3b00269a52a..b0049be00c70 100644
--- a/tools/testing/kunit/configs/all_tests.config
+++ b/tools/testing/kunit/configs/all_tests.config
@@ -38,9 +38,6 @@ CONFIG_IWLWIFI=y
 CONFIG_DAMON=y
 CONFIG_DAMON_VADDR=y
 CONFIG_DAMON_PADDR=y
-CONFIG_DEBUG_FS=y
-CONFIG_DAMON_DBGFS=y
-CONFIG_DAMON_DBGFS_DEPRECATED=y
 
 CONFIG_REGMAP_BUILD=y
 
-- 
2.39.5

[RFC PATCH 6/7] mm/damon: remove DAMON debugfs interface kunit tests

[SeongJae Park]

It's time to remove DAMON debugfs interface, which has deprecated long
before in February 2023.  Read the cover letter of this patch series for
more details.

Remove kunit tests for the interface, to prevent unnecessary test
failures.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/Kconfig             |  12 ---
 mm/damon/dbgfs.c             |   2 -
 mm/damon/tests/.kunitconfig  |   7 --
 mm/damon/tests/dbgfs-kunit.h | 173 -----------------------------------
 4 files changed, 194 deletions(-)
 delete mode 100644 mm/damon/tests/dbgfs-kunit.h

diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
index 35b72f88983a..5ee5e62c0a1e 100644
--- a/mm/damon/Kconfig
+++ b/mm/damon/Kconfig
@@ -89,18 +89,6 @@ config DAMON_DBGFS
 	default y
 	depends on DAMON_DBGFS_DEPRECATED
 
-config DAMON_DBGFS_KUNIT_TEST
-	bool "Test for damon debugfs interface" if !KUNIT_ALL_TESTS
-	depends on DAMON_DBGFS && KUNIT=y
-	default KUNIT_ALL_TESTS
-	help
-	  This builds the DAMON debugfs interface Kunit test suite.
-
-	  For more information on KUnit and unit tests in general, please refer
-	  to the KUnit documentation.
-
-	  If unsure, say N.
-
 config DAMON_RECLAIM
 	bool "Build DAMON-based reclaim (DAMON_RECLAIM)"
 	depends on DAMON_PADDR
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index b4213bc47e44..5664c2cb0a5e 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -1144,5 +1144,3 @@ static int __init damon_dbgfs_init(void)
 }
 
 module_init(damon_dbgfs_init);
-
-#include "tests/dbgfs-kunit.h"
diff --git a/mm/damon/tests/.kunitconfig b/mm/damon/tests/.kunitconfig
index a73be044fc9b..36a450f57b58 100644
--- a/mm/damon/tests/.kunitconfig
+++ b/mm/damon/tests/.kunitconfig
@@ -13,10 +13,3 @@ CONFIG_DAMON_VADDR_KUNIT_TEST=y
 CONFIG_SYSFS=y
 CONFIG_DAMON_SYSFS=y
 CONFIG_DAMON_SYSFS_KUNIT_TEST=y
-
-# for DAMON debugfs interface
-CONFIG_DEBUG_FS=y
-CONFIG_DAMON_PADDR=y
-CONFIG_DAMON_DBGFS_DEPRECATED=y
-CONFIG_DAMON_DBGFS=y
-CONFIG_DAMON_DBGFS_KUNIT_TEST=y
diff --git a/mm/damon/tests/dbgfs-kunit.h b/mm/damon/tests/dbgfs-kunit.h
deleted file mode 100644
index d2ecfcc8db86..000000000000
--- a/mm/damon/tests/dbgfs-kunit.h
+++ /dev/null
@@ -1,173 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * DAMON Debugfs Interface Unit Tests
- *
- * Author: SeongJae Park <sj@kernel.org>
- */
-
-#ifdef CONFIG_DAMON_DBGFS_KUNIT_TEST
-
-#ifndef _DAMON_DBGFS_TEST_H
-#define _DAMON_DBGFS_TEST_H
-
-#include <kunit/test.h>
-
-static void damon_dbgfs_test_str_to_ints(struct kunit *test)
-{
-	char *question;
-	int *answers;
-	int expected[] = {12, 35, 46};
-	ssize_t nr_integers = 0, i;
-
-	question = "123";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)1, nr_integers);
-	KUNIT_EXPECT_EQ(test, 123, answers[0]);
-	kfree(answers);
-
-	question = "123abc";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)1, nr_integers);
-	KUNIT_EXPECT_EQ(test, 123, answers[0]);
-	kfree(answers);
-
-	question = "a123";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)0, nr_integers);
-	kfree(answers);
-
-	question = "12 35";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)2, nr_integers);
-	for (i = 0; i < nr_integers; i++)
-		KUNIT_EXPECT_EQ(test, expected[i], answers[i]);
-	kfree(answers);
-
-	question = "12 35 46";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)3, nr_integers);
-	for (i = 0; i < nr_integers; i++)
-		KUNIT_EXPECT_EQ(test, expected[i], answers[i]);
-	kfree(answers);
-
-	question = "12 35 abc 46";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)2, nr_integers);
-	for (i = 0; i < 2; i++)
-		KUNIT_EXPECT_EQ(test, expected[i], answers[i]);
-	kfree(answers);
-
-	question = "";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)0, nr_integers);
-	kfree(answers);
-
-	question = "\n";
-	answers = str_to_ints(question, strlen(question), &nr_integers);
-	KUNIT_EXPECT_EQ(test, (ssize_t)0, nr_integers);
-	kfree(answers);
-}
-
-static void damon_dbgfs_test_set_targets(struct kunit *test)
-{
-	struct damon_ctx *ctx = dbgfs_new_ctx();
-	char buf[64];
-
-	if (!damon_is_registered_ops(DAMON_OPS_PADDR)) {
-		dbgfs_destroy_ctx(ctx);
-		kunit_skip(test, "PADDR not registered");
-	}
-
-	/* Make DAMON consider target has no pid */
-	damon_select_ops(ctx, DAMON_OPS_PADDR);
-
-	dbgfs_set_targets(ctx, 0, NULL);
-	sprint_target_ids(ctx, buf, 64);
-	KUNIT_EXPECT_STREQ(test, (char *)buf, "\n");
-
-	dbgfs_set_targets(ctx, 1, NULL);
-	sprint_target_ids(ctx, buf, 64);
-	KUNIT_EXPECT_STREQ(test, (char *)buf, "42\n");
-
-	dbgfs_set_targets(ctx, 0, NULL);
-	sprint_target_ids(ctx, buf, 64);
-	KUNIT_EXPECT_STREQ(test, (char *)buf, "\n");
-
-	dbgfs_destroy_ctx(ctx);
-}
-
-static void damon_dbgfs_test_set_init_regions(struct kunit *test)
-{
-	struct damon_ctx *ctx = damon_new_ctx();
-	/* Each line represents one region in ``<target idx> <start> <end>`` */
-	char * const valid_inputs[] = {"1 10 20\n 1   20 30\n1 35 45",
-		"1 10 20\n",
-		"1 10 20\n0 39 59\n0 70 134\n  1  20 25\n",
-		""};
-	/* Reading the file again will show sorted, clean output */
-	char * const valid_expects[] = {"1 10 20\n1 20 30\n1 35 45\n",
-		"1 10 20\n",
-		"0 39 59\n0 70 134\n1 10 20\n1 20 25\n",
-		""};
-	char * const invalid_inputs[] = {"3 10 20\n",	/* target not exists */
-		"1 10 20\n 1 14 26\n",		/* regions overlap */
-		"0 10 20\n1 30 40\n 0 5 8"};	/* not sorted by address */
-	char *input, *expect;
-	int i, rc;
-	char buf[256];
-
-	if (!damon_is_registered_ops(DAMON_OPS_PADDR)) {
-		damon_destroy_ctx(ctx);
-		kunit_skip(test, "PADDR not registered");
-	}
-
-	damon_select_ops(ctx, DAMON_OPS_PADDR);
-
-	dbgfs_set_targets(ctx, 3, NULL);
-
-	/* Put valid inputs and check the results */
-	for (i = 0; i < ARRAY_SIZE(valid_inputs); i++) {
-		input = valid_inputs[i];
-		expect = valid_expects[i];
-
-		rc = set_init_regions(ctx, input, strnlen(input, 256));
-		KUNIT_EXPECT_EQ(test, rc, 0);
-
-		memset(buf, 0, 256);
-		sprint_init_regions(ctx, buf, 256);
-
-		KUNIT_EXPECT_STREQ(test, (char *)buf, expect);
-	}
-	/* Put invalid inputs and check the return error code */
-	for (i = 0; i < ARRAY_SIZE(invalid_inputs); i++) {
-		input = invalid_inputs[i];
-		pr_info("input: %s\n", input);
-		rc = set_init_regions(ctx, input, strnlen(input, 256));
-		KUNIT_EXPECT_EQ(test, rc, -EINVAL);
-
-		memset(buf, 0, 256);
-		sprint_init_regions(ctx, buf, 256);
-
-		KUNIT_EXPECT_STREQ(test, (char *)buf, "");
-	}
-
-	dbgfs_set_targets(ctx, 0, NULL);
-	damon_destroy_ctx(ctx);
-}
-
-static struct kunit_case damon_test_cases[] = {
-	KUNIT_CASE(damon_dbgfs_test_str_to_ints),
-	KUNIT_CASE(damon_dbgfs_test_set_targets),
-	KUNIT_CASE(damon_dbgfs_test_set_init_regions),
-	{},
-};
-
-static struct kunit_suite damon_test_suite = {
-	.name = "damon-dbgfs",
-	.test_cases = damon_test_cases,
-};
-kunit_test_suite(damon_test_suite);
-
-#endif /* _DAMON_TEST_H */
-
-#endif	/* CONFIG_DAMON_KUNIT_TEST */
-- 
2.39.5