Hello, On Wed, Dec 13, 2017 at 11:30:48AM +0800, jianchao.wang wrote: > > + } else { > > + srcu_idx = srcu_read_lock(hctx->queue_rq_srcu); > > + if (!blk_mark_rq_complete(rq)) > > + __blk_mq_complete_request(rq); > > + srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx); > > The __blk_mq_complete_request() could be executed in irq context. There should not be any > sleeping operations in it. If just synchronize with the timeout path to ensure the aborted_gstate > to be seen, only rcu is needed here ,as well as the blk_mq_timeout_work. Sure, but it's just a lot cleaner to use the same to protect both issue and completion; otherwise, whoever who wants to synchronize against them have to do awkward double rcu locking. Thanks. -- tejun