Hello, On Thu, Aug 29, 2019 at 09:39:28PM +0800, Hillf Danton wrote: > > + on_q_ns = ktime_get_ns() - rq->alloc_time_ns; > > + rq_wait_ns = rq->start_time_ns - rq->alloc_time_ns; > > + > ehm... alloc_time makes no sense wrt start_time if this is their only > use. What are you trying to measure with the two stamps if they are > meaningfully apart? Queue depth depletion. > > + rq_qos_add(q, rqos); > > + ret = blkcg_activate_policy(q, &blkcg_policy_iocost); > > + if (ret) { > > + rq_qos_del(q, rqos); > > free_percpu(ioc->pcpu_stat); Good catch. Will send a follow up patch. Thanks. -- tejun