Re: [PATCH] nvme: trace: add disk name to tracepoints
From: Keith Busch
Date: Wed Jun 27 2018 - 21:00:43 EST
Thinking more on this, not using the hw qid really limits the utility
out of using these trace events: We may not be able to match a completion
to the submission without it since cmdid alone isn't enough to match up
the two events.
Here's an updated proposal and actually tested. I was also able to
combine admin and io submissions.
---
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b429d51..c647883 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 46df030..f46bde2 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -652,10 +654,7 @@ 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);
- else
- trace_nvme_setup_admin_cmd(cmd);
+ trace_nvme_setup_nvm_cmd(req, cmd);
return ret;
}
EXPORT_SYMBOL_GPL(nvme_setup_cmd);
diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
index 01390f0..bca3451 100644
--- a/drivers/nvme/host/trace.h
+++ b/drivers/nvme/host/trace.h
@@ -75,34 +75,9 @@ const char *nvme_trace_parse_nvm_cmd(struct trace_seq *p, u8 opcode,
#define __parse_nvme_cmd(opcode, cdw10) \
nvme_trace_parse_nvm_cmd(p, opcode, cdw10)
-TRACE_EVENT(nvme_setup_admin_cmd,
- TP_PROTO(struct nvme_command *cmd),
- TP_ARGS(cmd),
- TP_STRUCT__entry(
- __field(u8, opcode)
- __field(u8, flags)
- __field(u16, cid)
- __field(u64, metadata)
- __array(u8, cdw10, 24)
- ),
- TP_fast_assign(
- __entry->opcode = cmd->common.opcode;
- __entry->flags = cmd->common.flags;
- __entry->cid = cmd->common.command_id;
- __entry->metadata = le64_to_cpu(cmd->common.metadata);
- 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,
- 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 +88,7 @@ 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;
@@ -125,8 +100,12 @@ TRACE_EVENT(nvme_setup_nvm_cmd,
TP_printk("qid=%d, nsid=%u, cmdid=%u, flags=0x%x, meta=0x%llx, cmd=(%s %s)",
__entry->qid, __entry->nsid, __entry->cid,
__entry->flags, __entry->metadata,
- show_opcode_name(__entry->opcode),
- __parse_nvme_cmd(__entry->opcode, __entry->cdw10))
+ __entry->qid ?
+ show_opcode_name(__entry->opcode) :
+ show_admin_opcode_name(__entry->opcode),
+ __entry->qid ?
+ __parse_nvme_cmd(__entry->opcode, __entry->cdw10) :
+ __parse_nvme_admin_cmd(__entry->opcode, __entry->cdw10))
);
TRACE_EVENT(nvme_complete_rq,
@@ -141,7 +120,7 @@ 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 e3147eb..af91b2d 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);
--