On Mon, Mar 25, 2019 at 08:05:53PM -0700, jianchao.wang wrote: > What if there used to be a io scheduler and leave some stale requests of sched tags ? > Or the nr_hw_queues was decreased and leave the hctx->fq->flush_rq ? Requests internally queued in scheduler or block layer are not eligible for the nvme driver's iterator callback. We only use it to reclaim dispatched requests that the target can't return, which only applies to requests that must have a valid rq->tag value from hctx->tags. > The stable request could be some tings freed and used > by others and the state field happen to be overwritten to non-zero... I am not sure I follow what this means. At least for nvme, every queue sharing the same tagset is quiesced and frozen, there should be no request state in flux at the time we iterate.
