Re: [PATCH -next 1/6] blk-wbt: fix that wbt can't be disabled by default

[Yu Kuai]

Hi,

在 2023/05/11 23:19, Christoph Hellwig 写道:
> On Thu, May 11, 2023 at 09:45:04AM +0800, Yu Kuai wrote:
> > @@ -730,8 +730,9 @@ void wbt_enable_default(struct gendisk *disk)
> >   {
> >   	struct request_queue *q = disk->queue;
> >   	struct rq_qos *rqos;
> > -	bool disable_flag = q->elevator &&
> > -		    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags);
> > +	bool disable_flag = (q->elevator &&
> > +		    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags)) ||
> > +		    !IS_ENABLED(CONFIG_BLK_WBT_MQ);
>
> Not really new in your patch, but I find the logic here very confusing.
> First the disable_flag really should be enable instead, as that's how
> it's actually checked, and then spelling out the conditions a bit more
> would really help readability.  E.g.
>
> 	bool enabled = IS_ENABLED(CONFIG_BLK_WBT_MQ);
>
> 	if (q->elevator &&
> 	    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags))
> 		enable = false;

Of course, this looks better, I'll do this in v2.

Thanks,
Kuai
> .