Re: [PATCH v3 08/13] mm/slab: change struct slabobj_ext to a union

"Vlastimil Babka (SUSE)" <[email protected]> Fri, 31 Jul 2026 15:52:44 +0200
Newsgroups org.kernel.vger.cgroups,org.kernel.vger.linux-kernel,org.kvack.linux-mm
Message-ID <[email protected]>
On 7/30/26 13:58, Hao Li wrote:
> On Mon, Jul 27, 2026 at 02:54:02PM +0200, Vlastimil Babka (SUSE) wrote:
>> @@ -7933,7 +7936,7 @@ static int calculate_sizes(struct kmem_cache_args *args, struct kmem_cache *s)
>>  	aligned_size = ALIGN(size, s->align);
>>  #if defined(CONFIG_SLAB_OBJ_EXT) && defined(CONFIG_64BIT)
>>  	if (slab_args_unmergeable(args, s->flags) &&
>> -			(aligned_size - size >= sizeof(struct slabobj_ext)))
>> +			(aligned_size - size >= cache_obj_ext_size(s)))
> 
> Nit: cache_obj_ext_size() could return 0, and the checking will always be true.
> But I think this is harmless.

Yeah should be harmless as then no objexts are used for the cache anyway.
Thanks!

>>  		s->flags |= SLAB_OBJ_EXT_IN_OBJ;
>>  #endif
>>  	size = aligned_size;
>> 
>> -- 
>> 2.55.0
>> 
>