Re: [PATCH 2/3] mm, slab: use an enum to define SLAB_ cache creation flags

Vlastimil Babka
2024-02-23T16:43:34Z

On 2/23/24 04:12, Christoph Lameter (Ampere) wrote:
> On Tue, 20 Feb 2024, Vlastimil Babka wrote:
>
>> diff --git a/mm/slub.c b/mm/slub.c
>> index 2ef88bbf56a3..a93c5a17cbbb 100644
>> --- a/mm/slub.c
>> +++ b/mm/slub.c
>> @@ -306,13 +306,13 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
>>
>> /* Internal SLUB flags */
>> /* Poison object */
>> -#define __OBJECT_POISON ((slab_flags_t __force)0x80000000U)
>> +#define __OBJECT_POISON __SF_BIT(_SLAB_OBJECT_POISON)
>> /* Use cmpxchg_double */
>>
>> #ifdef system_has_freelist_aba
>> -#define __CMPXCHG_DOUBLE ((slab_flags_t __force)0x40000000U)
>> +#define __CMPXCHG_DOUBLE __SF_BIT(_SLAB_CMPXCHG_DOUBLE)
>> #else
>> -#define __CMPXCHG_DOUBLE ((slab_flags_t __force)0U)
>> +#define __CMPXCHG_DOUBLE 0
>> #endif
>
> Maybe its good to put these internal flags together with the other flags.
> After all there is no other slab allocator available anymore and having
> them all together avoids confusion.

Good poiint, will do. Then I can also #undef the helper macro after the last
flag.