Messages in this thread | | | Date | Sun, 27 Oct 2019 16:09:37 +0100 | From | Christoph Hellwig <> | Subject | Re: [RFC PATCH 3/3] nvme: Introduce nvme_execute_passthru_rq_nowait() |
| |
On Fri, Oct 25, 2019 at 02:25:35PM -0600, Logan Gunthorpe wrote: > This function is similar to nvme_execute_passthru_rq() but does > not wait and will call a callback when the request is complete. > > The new function can also be called in interrupt context, so if there > are side effects, the request will be executed in a work queue to > avoid sleeping.
Why would you ever call it from interrupt context? All the target submission handlers should run in process context.
> +void nvme_execute_passthru_rq_nowait(struct request *rq, rq_end_io_fn *done) > +{ > + struct nvme_command *cmd = nvme_req(rq)->cmd; > + struct nvme_ctrl *ctrl = nvme_req(rq)->ctrl; > + struct nvme_ns *ns = rq->q->queuedata; > + struct gendisk *disk = ns ? ns->disk : NULL; > + u32 effects; > + > + /* > + * This function may be called in interrupt context, so we cannot sleep > + * but nvme_passthru_[start|end]() may sleep so we need to execute > + * the command in a work queue. > + */ > + effects = nvme_command_effects(ctrl, ns, cmd->common.opcode); > + if (effects) { > + rq->end_io = done; > + INIT_WORK(&nvme_req(rq)->work, nvme_execute_passthru_rq_work); > + queue_work(nvme_wq, &nvme_req(rq)->work);
But independent of the target code - I'd much rather leave this to the caller. Just call nvme_command_effects in the target code, then if there are not side effects use blk_execute_rq_nowait directly, else schedule a workqueue in the target code and call nvme_execute_passthru_rq from it.
| |