+ mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix.patch added to mm-new branch

+ mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix
has been added to the -mm mm-new branch.  Its filename is
     mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix.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: Andrew Morton <akpm@linux-foundation.org>
Subject: mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix
Date: Mon Jun 29 09:44:25 AM PDT 2026

- fix obj_to_class_idx() defined but not used
- remove duplicated #ifdef CONFIG_COMPACTION

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202606291933.Cw5TBs54-lkp@intel.com/
Cc: Barry Song <baohua@kernel.org>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Wenchao Hao <haowenchao@xiaomi.com>
Cc: Xueyuan Chen <xueyuan.chen21@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/zsmalloc.c |   13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

--- a/mm/zsmalloc.c~mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix
+++ a/mm/zsmalloc.c
@@ -796,12 +796,6 @@ static void obj_to_zpdesc(unsigned long
 	*zpdesc = pfn_zpdesc(obj >> ZS_OBJ_PFN_SHIFT);
 }
 
-/* Folds to 0 when ZS_OBJ_CLASS_BITS == 0; no ifdef needed at callers. */
-static unsigned int obj_to_class_idx(unsigned long obj)
-{
-	return (obj >> ZS_OBJ_IDX_BITS) & ZS_OBJ_CLASS_MASK;
-}
-
 /**
  * location_to_obj - encode (<zpdesc>, <obj_idx>, <class_idx>) into obj value
  * @zpdesc: zpdesc object resides in zspage
@@ -1719,9 +1713,12 @@ static void lock_zspage(struct zspage *z
 	}
 	zspage_read_unlock(zspage);
 }
-#endif /* CONFIG_COMPACTION */
 
-#ifdef CONFIG_COMPACTION
+/* Folds to 0 when ZS_OBJ_CLASS_BITS == 0; no ifdef needed at callers. */
+static unsigned int obj_to_class_idx(unsigned long obj)
+{
+	return (obj >> ZS_OBJ_IDX_BITS) & ZS_OBJ_CLASS_MASK;
+}
 
 static void replace_sub_page(struct size_class *class, struct zspage *zspage,
 				struct zpdesc *newzpdesc, struct zpdesc *oldzpdesc)
_

Patches currently in -mm which might be from akpm@linux-foundation.org are

mm-mincore-use-walk_page_range_vma-in-do_mincore-fix.patch
mm-page_owner-add-print_mode-filter-fix.patch
mm-annotate-data-race-in-cpu_needs_drain-fix.patch
mm-zsmalloc-encode-class-index-in-obj-value-for-lockless-class-lookup-fix.patch
drivers-media-v4l2-core-v4l2-vp9c-reduce-inlining.patch