On Wed, Jun 27, 2018 at 11:06:22AM +0300, Sagi Grimberg wrote:
>
> > > Not related to your patch, but I did notice that the req->q->id isn't
> > > really useful here since that's not the hardware context identifier.
> > > That's just some ida assigned software identifier. For the admin command
> > > completion trace, it's actually a little confusing to see the qid in the
> > > trace.
> >
> > It was actually requested by Martin so we can easily see which request
> > got dispatched/completed on which request queue.
>
> Would be good in the future to display the hwqid, but we'll need to work
> before we can do that.
I'd really like to see nvme qid, and it would allow for nice trace
filters. We could use a little help from blk-mq to get the hctx's
queue_num from a struct request. I think following should get us that
(haven't tested just yet)
---
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b429d515b568..c6478833464d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -466,6 +466,12 @@ struct request *blk_mq_alloc_request_hctx(struct
request_queue *q,
}
EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
+unsigned int blk_mq_request_hctx_idx(struct request *rq)
+{
+ return blk_mq_map_queue(rq->q, rq->mq_ctx->cpu)->queue_num;
+}
+EXPORT_SYMBOL_GPL(blk_mq_request_hctx_idx);
+
static void __blk_mq_free_request(struct request *rq)
{
struct request_queue *q = rq->q;
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 46df030b2c3f..6a30c154aa99 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -653,7 +653,7 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct
request *req,
cmd->common.command_id = req->tag;
if (ns)
- trace_nvme_setup_nvm_cmd(req->q->id, cmd);
+ trace_nvme_setup_nvm_cmd(req, cmd);
else
trace_nvme_setup_admin_cmd(cmd);
return ret;
diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
index 01390f0e1671..95ebe803424b 100644
--- a/drivers/nvme/host/trace.h
+++ b/drivers/nvme/host/trace.h
@@ -79,6 +79,7 @@ TRACE_EVENT(nvme_setup_admin_cmd,
TP_PROTO(struct nvme_command *cmd),
TP_ARGS(cmd),
TP_STRUCT__entry(
+ __field(int, qid)
__field(u8, opcode)
__field(u8, flags)
__field(u16, cid)
@@ -86,6 +87,7 @@ TRACE_EVENT(nvme_setup_admin_cmd,
__array(u8, cdw10, 24)
),
TP_fast_assign(
+ __entry->qid = 0;
__entry->opcode = cmd->common.opcode;
__entry->flags = cmd->common.flags;
__entry->cid = cmd->common.command_id;
@@ -93,16 +95,16 @@ TRACE_EVENT(nvme_setup_admin_cmd,
memcpy(__entry->cdw10, cmd->common.cdw10,
sizeof(__entry->cdw10));
),
- TP_printk(" cmdid=%u, flags=0x%x, meta=0x%llx, cmd=(%s %s)",
- __entry->cid, __entry->flags, __entry->metadata,
+ TP_printk("qid=%d, cmdid=%u, flags=0x%x, meta=0x%llx, cmd=(%s %s)",
+ __entry->qid, __entry->cid, __entry->flags,
__entry->metadata,
show_admin_opcode_name(__entry->opcode),
__parse_nvme_admin_cmd(__entry->opcode, __entry->cdw10))
);
TRACE_EVENT(nvme_setup_nvm_cmd,
- TP_PROTO(int qid, struct nvme_command *cmd),
- TP_ARGS(qid, cmd),
+ TP_PROTO(struct request *req, struct nvme_command *cmd),
+ TP_ARGS(req, cmd),
TP_STRUCT__entry(
__field(int, qid)
__field(u8, opcode)
@@ -113,7 +115,7 @@ TRACE_EVENT(nvme_setup_nvm_cmd,
__array(u8, cdw10, 24)
),
TP_fast_assign(
- __entry->qid = qid;
+ __entry->qid = blk_mq_request_hctx_idx(req) +
!!req->rq_disk;
__entry->opcode = cmd->common.opcode;
__entry->flags = cmd->common.flags;
__entry->cid = cmd->common.command_id;
@@ -141,7 +143,7 @@ TRACE_EVENT(nvme_complete_rq,
__field(u16, status)
),
TP_fast_assign(
- __entry->qid = req->q->id;
+ __entry->qid = blk_mq_request_hctx_idx(req) +
!!req->rq_disk;
__entry->cid = req->tag;
__entry->result = le64_to_cpu(nvme_req(req)->result.u64);
__entry->retries = nvme_req(req)->retries;
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index e3147eb74222..af91b2d31a04 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -248,6 +248,7 @@ static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
}
+unsigned int blk_mq_request_hctx_idx(struct request *rq);
int blk_mq_request_started(struct request *rq);
void blk_mq_start_request(struct request *rq);
void blk_mq_end_request(struct request *rq, blk_status_t error);
--
