> +static unsigned int nvme_get_write_stream(struct nvme_ns *ns,
> + struct request *req)
> +{
> + unsigned int streamid = 0;
> +
> + if (req_op(req) != REQ_OP_WRITE || !blk_stream_valid(req->cmd_flags) ||
> + !ns->nr_streams)
> + return 0;
Might make more sense to do this check in the caller?
> +
> + if (req->cmd_flags & REQ_WRITE_SHORT)
> + streamid = 1;
> + else if (req->cmd_flags & REQ_WRITE_MEDIUM)
> + streamid = 2;
> + else if (req->cmd_flags & REQ_WRITE_LONG)
> + streamid = 3;
> + else if (req->cmd_flags & REQ_WRITE_EXTREME)
> + streamid = 4;
> +
> + if (streamid < BLK_MAX_STREAM)
Can happen per the index above.
> + req->q->stream_writes[streamid] += blk_rq_bytes(req) >> 9;
> +
> + return (streamid % (ns->nr_streams + 1));
Should we do smarted collapsing? e.g. short + medium and long + extreme
for two? What for three? Does one extra stream make sense in this
scheme?
> + dev_info(ctrl->device, "streams: msl=%u, nssa=%u, nsso=%u, sws=%u "
> + "sgs=%u, nsa=%u, nso=%u\n", s.msl, s.nssa,
> + s.nsso, s.sws, s.sgs, s.nsa, s.nso);
Way to chatty.
> + if (ctrl->oacs & NVME_CTRL_OACS_DIRECTIVES)
> + dev_info(ctrl->dev, "supports directives\n");
Same. Use nvme-cli for that sort of info.
> ctrl->npss = id->npss;
> prev_apsta = ctrl->apsta;
> if (ctrl->quirks & NVME_QUIRK_NO_APST) {
> @@ -2060,6 +2201,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
> goto out_free_id;
> }
>
> + if (ctrl->oacs & NVME_CTRL_OACS_DIRECTIVES)
> + nvme_config_streams(ns);
This sets aside four streams on any device that supports them, and
will probably kill performance on them unless you have a workload
that actually uses those streams. I think they need to be allocated
lazily.
