[harry:kmalloc-no-objext-rfc-v1r2 3/3] mm/slab.h:397:10: error: use of undeclared identifier 'KMALLOC_NO_OBJ_EXT'

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/harry/linux.git kmalloc-no-objext-rfc-v1r2
head:   a734609d2f387a9e682d352e9f28599744cc300b
commit: a734609d2f387a9e682d352e9f28599744cc300b [3/3] mm/slab: prevent unbounded recursion in free path with new kmalloc type
config: hexagon-allnoconfig (https://download.01.org/0day-ci/archive/20260702/202607021256.JaPXbde2-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 0a2fb2a2269da0e2a3e230beb6cad39ca314db33)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260702/202607021256.JaPXbde2-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202607021256.JaPXbde2-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from mm/mempool.c:19:
>> mm/slab.h:397:10: error: use of undeclared identifier 'KMALLOC_NO_OBJ_EXT'
     397 |                 type = KMALLOC_NO_OBJ_EXT;
         |                        ^~~~~~~~~~~~~~~~~~
   1 error generated.
--
   In file included from mm/oom_kill.c:51:
>> mm/slab.h:397:10: error: use of undeclared identifier 'KMALLOC_NO_OBJ_EXT'
     397 |                 type = KMALLOC_NO_OBJ_EXT;
         |                        ^~~~~~~~~~~~~~~~~~
   mm/oom_kill.c:508:28: warning: variable 'oom_reaper_th' set but not used [-Wunused-but-set-global]
     508 | static struct task_struct *oom_reaper_th;
         |                            ^
   1 warning and 1 error generated.


vim +/KMALLOC_NO_OBJ_EXT +397 mm/slab.h

   381	
   382	/*
   383	 * Find the kmem_cache structure that serves a given size of
   384	 * allocation
   385	 *
   386	 * This assumes size is larger than zero and not larger than
   387	 * KMALLOC_MAX_CACHE_SIZE and the caller must check that.
   388	 */
   389	static inline struct kmem_cache *
   390	kmalloc_slab(size_t size, kmem_buckets *b, gfp_t flags, kmalloc_token_t token,
   391		     unsigned int alloc_flags)
   392	{
   393		unsigned int index;
   394		enum kmalloc_cache_type type = kmalloc_type(flags, token);
   395	
   396		if (alloc_flags & SLAB_ALLOC_NO_OBJ_EXT)
 > 397			type = KMALLOC_NO_OBJ_EXT;
   398	
   399		if (!b)
   400			b = &kmalloc_caches[type];
   401		if (size <= 192)
   402			index = kmalloc_size_index[size_index_elem(size)];
   403		else
   404			index = fls(size - 1);
   405	
   406		return (*b)[index];
   407	}
   408	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki