Re: [blk] 8c5035dfbb: fio.read_iops -10.6% regression

Ming Lei
2022-10-09T08:43:26Z

On Sat, Oct 08, 2022 at 04:00:10PM +0800, Yu Kuai wrote:
> Hi,
>
> 在 2022/10/08 10:50, kernel test robot 写道:
> > Greeting,
> >
> > FYI, we noticed a -10.6% regression of fio.read_iops due to commit:
>
> I don't know how this is working but I'm *sure* this commit won't affect

Looks it is wrong to move

wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));

before rq_qos_add() in wbt_init().

Without adding wbt rq_qos, wbt_set_write_cache is just a nop.

thanks,
Ming