period_at         412 block/blk-iocost.c 	u32				period_at;	/* wallclock starttime */
period_at         872 block/blk-iocost.c 			(now->now - ioc->period_at) * now->vrate;
period_at         882 block/blk-iocost.c 	ioc->period_at = now->now;
period_at        1965 block/blk-iocost.c 	ioc->period_at = ktime_to_us(ktime_get());