On 11/23/21 11:59 AM, Christoph Hellwig wrote:
> On Tue, Nov 23, 2021 at 11:58:42AM -0700, Jens Axboe wrote:
>> On 11/23/21 11:50 AM, Christoph Hellwig wrote:
>>>> + spin_lock_irq(&q->stats->lock);
>>>> + if (q->poll_stat) {
>>>> + spin_unlock_irq(&q->stats->lock);
>>>> + kfree(poll_stat);
>>>> + return true;
>>>> + }
>>>> + q->poll_stat = poll_stat;
>>>> + spin_unlock_irq(&q->stats->lock);
>>>
>>> If we'd use a cmpxchg to install the pointer we could keep the
>>> blk_queue_stats definition private.
>>
>> How about we just move this alloc+enable logic into blk-stat.c instead?
>
> That's a good idea either way. But I think cmpxchg is much better
> for installing a pointer than an unrelated lock.
True, I'll do that while moving it.
--
Jens Axboe
