Re: block/blk-zoned.c:579:5-24: WARNING: atomic_dec_and_test variation before object free at line 583.

[Damien Le Moal]

On 11/6/24 00:56, Jens Axboe wrote:
> On 11/5/24 8:37 AM, Christoph Hellwig wrote:
>> On Tue, Nov 05, 2024 at 08:36:33AM -0700, Jens Axboe wrote:
>>> On 11/5/24 8:34 AM, Christoph Hellwig wrote:
>>>> On Tue, Nov 05, 2024 at 06:52:25AM +0800, kernel test robot wrote:
>>>>>>> block/blk-zoned.c:579:5-24: WARNING: atomic_dec_and_test variation before object free at line 583.
>>>>
>>>> Does anyone know what this warning is supposed to mean?
>>>
>>> It's supposed to mean "use refcount_t for things like this".
>>
>> Have we finally resolved the performance problems with refcount_t for
>> fast path operations?
> 
> I mean it's closer, but it's still slower. Will always be so. Does it
> matter for zoned devices? Probably not.
> 
> I don't think it matters for this case. It's not like the ref itself is
> something that is user controllable in terms of being able to get
> anywhere near an overflow.

OK. Will work on a patch to switch to refcount.


-- 
Damien Le Moal
Western Digital Research