[PATCHv2 4/4] nvme: add disk name to tracepoints

Keith Busch
2018-06-28T21:51:21Z

This will print the disk name to the nvme trace for disk based requests
so a user can better distinguish traffic to different disks. This allows
disk based filters. For example, to see only nvme0n2 traffic:

echo "disk == nvme0n2" > /sys/kernel/debug/tracing/events/nvme/filter

Signed-off-by: Keith Busch <keith.busch@intel.com>
---
drivers/nvme/host/trace.c | 11 +++++++++++
drivers/nvme/host/trace.h | 27 ++++++++++++++++++++-------
2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/host/trace.c b/drivers/nvme/host/trace.c
index 41944bbef835..796a5bcf67b8 100644
--- a/drivers/nvme/host/trace.c
+++ b/drivers/nvme/host/trace.c
@@ -128,3 +128,14 @@ const char *nvme_trace_parse_nvm_cmd(struct trace_seq *p,
return nvme_trace_common(p, cdw10);
}
}
+
+const char *nvme_trace_disk_name(struct trace_seq *p, char *name)
+{
+ const char *ret = trace_seq_buffer_ptr(p);
+
+ if (name[0] != 0)
+ trace_seq_printf(p, "disk=%-.*s, ", DISK_NAME_LEN, name);
+ trace_seq_putc(p, 0);
+
+ return ret;
+}
diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
index a99b2929794a..d3522c373e5e 100644
--- a/drivers/nvme/host/trace.h
+++ b/drivers/nvme/host/trace.h
@@ -75,10 +75,15 @@ 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)

+const char *nvme_trace_disk_name(struct trace_seq *p, char *name);
+#define __print_nvme_disk_name(name) \
+ nvme_trace_disk_name(p, name)
+
TRACE_EVENT(nvme_setup_nvm_cmd,
TP_PROTO(struct request *req, struct nvme_command *cmd),
TP_ARGS(req, cmd),
TP_STRUCT__entry(
+ __array(char, disk, DISK_NAME_LEN)
__field(int, ctrl_id)
__field(int, qid)
__field(u8, opcode)
@@ -98,10 +103,14 @@ TRACE_EVENT(nvme_setup_nvm_cmd,
__entry->metadata = le64_to_cpu(cmd->common.metadata);
memcpy(__entry->cdw10, cmd->common.cdw10,
sizeof(__entry->cdw10));
+ req->rq_disk ?
+ memcpy(__entry->disk, req->rq_disk->disk_name, DISK_NAME_LEN) :
+ memset(__entry->disk, 0, DISK_NAME_LEN);
),
- TP_printk("nvme%d: qid=%d, cmdid=%u, nsid=%u, flags=0x%x, meta=0x%llx, cmd=(%s %s)",
- __entry->ctrl_id, __entry->qid, __entry->nsid,
- __entry->cid, __entry->flags, __entry->metadata,
+ TP_printk("nvme%d: %sqid=%d, cmdid=%u, nsid=%u, flags=0x%x, meta=0x%llx, cmd=(%s %s)",
+ __entry->ctrl_id, __print_nvme_disk_name(__entry->disk),
+ __entry->qid, __entry->nsid, __entry->cid,
+ __entry->flags, __entry->metadata,
__entry->qid ?
show_opcode_name(__entry->opcode) :
show_admin_opcode_name(__entry->opcode),
@@ -114,6 +123,7 @@ TRACE_EVENT(nvme_complete_rq,
TP_PROTO(struct request *req),
TP_ARGS(req),
TP_STRUCT__entry(
+ __array(char, disk, DISK_NAME_LEN)
__field(int, ctrl_id)
__field(int, qid)
__field(int, cid)
@@ -130,11 +140,14 @@ TRACE_EVENT(nvme_complete_rq,
__entry->retries = nvme_req(req)->retries;
__entry->flags = nvme_req(req)->flags;
__entry->status = nvme_req(req)->status;
+ req->rq_disk ?
+ memcpy(__entry->disk, req->rq_disk->disk_name, DISK_NAME_LEN) :
+ memset(__entry->disk, 0, DISK_NAME_LEN);
),
- TP_printk("nvme%d: qid=%d, cmdid=%u, res=%llu, retries=%u, flags=0x%x, status=%u",
- __entry->ctrl_id, __entry->qid, __entry->cid,
- __entry->result, __entry->retries, __entry->flags,
- __entry->status)
+ TP_printk("nvme%d: %sqid=%d, cmdid=%u, res=%llu, retries=%u, flags=0x%x, status=%u",
+ __entry->ctrl_id, __print_nvme_disk_name(__entry->disk),
+ __entry->qid, __entry->cid, __entry->result,
+ __entry->retries, __entry->flags, __entry->status)

);

--
2.14.3