On Mon, Apr 13, 2020 at 08:00:29PM +0300, Pavel Begunkov wrote: > On 13/04/2020 19:56, Pavel Begunkov wrote: > > On 13/04/2020 19:27, Tejun Heo wrote: > >> Changes from v1[1] > >> > >> * Dropped 0002-block-add-request-io_data_len.patch and updated to use > >> rq->stats_sectors instead as suggested by Pavel Begunkov. > > > > rq->stats_sectors is set only when there is QUEUE_FLAG_STATS, see > > blk_mq_start_request(). I don't see blk-iocost requiring it. Did I miss something? > > And there is no reason to not initialise it unconditionally. The updated patch turns on accounting when iocost is enabled on a queue. @@ -2267,6 +2295,7 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input, spin_lock_irq(&ioc->lock); if (enable) { + blk_stat_enable_accounting(ioc->rqos.q); blk_queue_flag_set(QUEUE_FLAG_RQ_ALLOC_TIME, ioc->rqos.q); ioc->enabled = true; } else { Thanks. -- tejun