+ mm-damon-sysfs-schemes-fix-double-increment-of-nr_regions.patch added to mm-new branch

+ mm-damon-sysfs-schemes-fix-double-increment-of-nr_regions.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/damon/sysfs-schemes: fix double increment of nr_regions
has been added to the -mm mm-new branch.  Its filename is
     mm-damon-sysfs-schemes-fix-double-increment-of-nr_regions.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-sysfs-schemes-fix-double-increment-of-nr_regions.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Vineet Agarwal <agarwal.vineet2006@gmail.com>
Subject: mm/damon/sysfs-schemes: fix double increment of nr_regions
Date: Tue, 12 May 2026 09:41:57 +0530

damos_sysfs_populate_region_dir() increments sysfs_regions->nr_regions
twice when adding a new region: once explicitly before
kobject_init_and_add(), and once again through the post-increment used for
the kobject name.

As a result, nr_regions no longer matches the actual number of live
regions, and region directory names skip numbers (1, 3, 5, ...).

Use the already incremented value for naming instead of incrementing
nr_regions a second time.

Link: https://lore.kernel.org/20260512041157.109845-1-agarwal.vineet2006@gmail.com
Fixes: 66178e4ec30a ("mm/damon/sysfs: use damos_walk() for update_schemes_tried_{bytes,regions}")
Signed-off-by: Vineet Agarwal <agarwal.vineet2006@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/damon/sysfs-schemes.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/damon/sysfs-schemes.c~mm-damon-sysfs-schemes-fix-double-increment-of-nr_regions
+++ a/mm/damon/sysfs-schemes.c
@@ -2998,7 +2998,7 @@ void damos_sysfs_populate_region_dir(str
 	if (kobject_init_and_add(&region->kobj,
 				&damon_sysfs_scheme_region_ktype,
 				&sysfs_regions->kobj, "%d",
-				sysfs_regions->nr_regions++)) {
+				sysfs_regions->nr_regions)) {
 		kobject_put(&region->kobj);
 	}
 }
_

Patches currently in -mm which might be from agarwal.vineet2006@gmail.com are

selftests-mm-khugepaged-initialize-file-contents-via-mmap.patch
mm-khugepaged-return-eagain-for-scan_page_has_private-in-madv_collapse.patch
selftests-mm-check-file-initialization-writes-in-split_huge_page_test.patch
mm-damon-sysfs-schemes-fix-double-increment-of-nr_regions.patch