[v3,2/2] trace nvme submit queue status

Commit Message

peng yu Dec. 17, 2018, 8:06 a.m. UTC

export nvme disk name, queue id, sq_head, sq_tail to trace event
usage example:
go to the event directory:
cd /sys/kernel/debug/tracing/events/nvme/nvme_sq
filter by disk name:
echo 'disk=="nvme1n1"' > filter
enable the event:
echo 1 > enable
check results from trace_pipe:
cat /sys/kernel/debug/tracing/trace_pipe
In practice, this patch help me debug hardware related
performant issue.

Signed-off-by: yupeng <[e-mail]>
---
 drivers/nvme/host/pci.c       |  7 +++++
 drivers/nvme/host/trace_pci.h | 57 +++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+)
 create mode 100644 drivers/nvme/host/trace_pci.h

Comments

Johannes Thumshirn Dec. 17, 2018, 8:33 a.m. UTC | #1

Is the addition of a trace_pci.h really needed? Why can't you just put
it in trace.h?

Byte,
	Johannes

Christoph Hellwig Dec. 17, 2018, 11:11 a.m. UTC | #2

On Mon, Dec 17, 2018 at 09:33:24AM +0100, Johannes Thumshirn wrote:
> Is the addition of a trace_pci.h really needed? Why can't you just put
> it in trace.h?

Agreed.  Especially as the concepts actually are generic, so we could
actually add the trace point to the rdma and fc transports as well
(not that they would be all that useful, so we probably shouldn't).

Patch

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index c33bb201b884..974cb05b3592 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -32,6 +32,9 @@ 
 #include <linux/sed-opal.h>
 #include <linux/pci-p2pdma.h>
 
+#define CREATE_TRACE_POINTS
+#include "trace_pci.h"
+
 #include "nvme.h"
 
 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
@@ -899,6 +902,10 @@  static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)
 	}
 
 	req = blk_mq_tag_to_rq(*nvmeq->tags, cqe->command_id);
+	trace_nvme_sq(req->rq_disk,
+		nvmeq->qid,
+		le16_to_cpu(cqe->sq_head),
+		nvmeq->sq_tail);
 	nvme_end_request(req, cqe->status, cqe->result);
 }
 
diff --git a/drivers/nvme/host/trace_pci.h b/drivers/nvme/host/trace_pci.h
new file mode 100644
index 000000000000..70fa853397f6
--- /dev/null
+++ b/drivers/nvme/host/trace_pci.h
@@ -0,0 +1,57 @@ 
+/*
+ * NVM Express device driver tracepoints
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM nvme
+
+#if !defined(_TRACE_NVME_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_NVME_H
+
+#include <linux/nvme.h>
+#include <linux/tracepoint.h>
+#include <linux/trace_seq.h>
+
+#include "nvme.h"
+
+const char *nvme_trace_disk_name(struct trace_seq *p, char *name);
+#define __print_disk_name(name)				\
+	nvme_trace_disk_name(p, name)
+
+TRACE_EVENT(nvme_sq,
+	    TP_PROTO(void *rq_disk, int qid, int sq_head, int sq_tail),
+	    TP_ARGS(rq_disk, qid, sq_head, sq_tail),
+	    TP_STRUCT__entry(
+		 __array(char, disk, DISK_NAME_LEN)
+		 __field(int, qid)
+		 __field(int, sq_head)
+		 __field(int, sq_tail)),
+	    TP_fast_assign(
+		__entry->qid = qid;
+		__entry->sq_head = sq_head;
+		__entry->sq_tail = sq_tail;
+		__assign_disk_name(__entry->disk, rq_disk);
+	    ),
+	    TP_printk("nvme: %s qid=%d head=%d tail=%d",
+		      __print_disk_name(__entry->disk),
+		      __entry->qid, __entry->sq_head, __entry->sq_tail)
+);
+
+#endif /* _TRACE_NVME_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace_pci
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>