Re: [akpm-mm:mm-new] BUILD SUCCESS WITH WARNING 15654b0268cd65b4e673510c0377774e61b86397

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 01 Jul 2026 02:30:11 +0800 kernel test robot <lkp@intel.com> wrote:

> tree/branch: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-new
> branch HEAD: 15654b0268cd65b4e673510c0377774e61b86397  mm/swap, PM: hibernate: atomically replace hibernation pin
> 
> Warning (recently discovered and may have been fixed):
> 
>     https://lore.kernel.org/oe-kbuild-all/202606291606.9h8aGniQ-lkp@intel.com
>     https://lore.kernel.org/oe-kbuild-all/202606291933.Cw5TBs54-lkp@intel.com
> 
>     mm/vmalloc.c:3590:16: warning: unused variable 'start' [-Wunused-variable]
>     mm/vmalloc.c:3590:23: warning: unused variable 'start' [-Wunused-variable]

Sigh, OK, I surrender.  Below.

>     mm/zsmalloc.c:1480:21: warning: 'obj_to_class_idx' defined but not used [-Wunused-function]

hm, I think I (re)fixed that one.


From: Andrew Morton <akpm@linux-foundation.org>
Subject: mm-vmalloc-map-contiguous-pages-in-batches-for-vmap-if-possible-fix
Date: Tue Jun 30 11:35:55 AM PDT 2026

avoid warnings on architectures whose flush_cache_vmap() don't reference
their args

Cc: Andrew Donnellan <ajd@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: "Barry Song (Xiaomi)" <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Wen Jiang <jiangwen6@xiaomi.com>
Cc: Wen Jiang <jiangwenxiaomi@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Xueyuan Chen <xueyuan.chen21@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmalloc.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/vmalloc.c~mm-vmalloc-map-contiguous-pages-in-batches-for-vmap-if-possible-fix
+++ a/mm/vmalloc.c
@@ -3629,6 +3629,7 @@ static int vmap_batched(unsigned long ad
 				prot, pages + idx, prev_shift);
 
 out:
+	(void)start;	/* several archs use a macro for flush_cache_vmap() */
 	flush_cache_vmap(start, end);
 	return err;
 }
_