[PATCH 2/9] mm/damon: rename CONFIG_DAMON_DBGFS to DAMON_DBGFS_DEPRECATED

[SeongJae Park <sj@kernel.org>]

DAMON debugfs interface is deprecated.  The fact has documented by
commit 5445fcbc4cda ("Docs/admin-guide/mm/damon/usage: add DAMON debugfs
interface deprecation notice").  Commit 620932cd2852 ("mm/damon/dbgfs:
print DAMON debugfs interface deprecation message") further started
printing a warning message when users still use it.  Many people don't
read documentation or kernel log, though.

Make the deprecation harder to be ignored using the approach of commit
eb07c4f39c3e ("mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED").
'make oldconfig' with 'CONFIG_DAMON_DBGFS=y' will get a new prompt with
the explicit deprecation notice on the name.  'make olddefconfig' with
'CONFIG_DAMON_DBGFS=y' will result in not building DAMON debugfs
interface.  If there is a real user of DAMON debugfs interface, they
will complain the change to the builder.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/Kconfig | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
index 29f43fbc2eff..fecb8172410c 100644
--- a/mm/damon/Kconfig
+++ b/mm/damon/Kconfig
@@ -71,7 +71,7 @@ config DAMON_SYSFS_KUNIT_TEST
 
 	  If unsure, say N.
 
-config DAMON_DBGFS
+config DAMON_DBGFS_DEPRECATED
 	bool "DAMON debugfs interface (DEPRECATED!)"
 	depends on DAMON_VADDR && DAMON_PADDR && DEBUG_FS
 	help
@@ -84,6 +84,11 @@ config DAMON_DBGFS
 	  (DAMON_SYSFS).  If you depend on this and cannot move, please report
 	  your usecase to damon@lists.linux.dev and linux-mm@kvack.org.
 
+config DAMON_DBGFS
+	bool
+	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
-- 
2.39.2