[PATCH v4 1/2] export trace.c helper functions to other modules

[PATCH v4 1/2] export trace.c helper functions to other modules

[yupeng]

Export bellow three functions:
nvme_trace_parse_admin_cmd
nvme_trace_parse_nvm_cmd
nvme_trace_disk_name
Thus any other modules which depends on nvme-core could use the trace
events in trace.h

Signed-off-by: yupeng <yupeng0921@gmail.com>
---
 drivers/nvme/host/trace.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/nvme/host/trace.c b/drivers/nvme/host/trace.c
index 25b0e310f4a8..8ca7079ed2bc 100644
--- a/drivers/nvme/host/trace.c
+++ b/drivers/nvme/host/trace.c
@@ -113,6 +113,7 @@ const char *nvme_trace_parse_admin_cmd(struct trace_seq *p,
 		return nvme_trace_common(p, cdw10);
 	}
 }
+EXPORT_SYMBOL_GPL(nvme_trace_parse_admin_cmd);
 
 const char *nvme_trace_parse_nvm_cmd(struct trace_seq *p,
 				     u8 opcode, u8 *cdw10)
@@ -128,6 +129,7 @@ const char *nvme_trace_parse_nvm_cmd(struct trace_seq *p,
 		return nvme_trace_common(p, cdw10);
 	}
 }
+EXPORT_SYMBOL_GPL(nvme_trace_parse_nvm_cmd);
 
 const char *nvme_trace_disk_name(struct trace_seq *p, char *name)
 {
@@ -139,3 +141,4 @@ const char *nvme_trace_disk_name(struct trace_seq *p, char *name)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(nvme_trace_disk_name);
-- 
2.17.1

[PATCH v4 2/2] trace nvme submit queue status

[yupeng]

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 <yupeng0921@gmail.com>
---
 drivers/nvme/host/pci.c   |  5 +++++
 drivers/nvme/host/trace.c |  2 ++
 drivers/nvme/host/trace.h | 21 +++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index c33bb201b884..52df2f7fef37 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -32,6 +32,7 @@
 #include <linux/sed-opal.h>
 #include <linux/pci-p2pdma.h>
 
+#include "trace.h"
 #include "nvme.h"
 
 #define SQ_SIZE(depth)		(depth * sizeof(struct nvme_command))
@@ -899,6 +900,10 @@ 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.c b/drivers/nvme/host/trace.c
index 8ca7079ed2bc..7bfaace23e1e 100644
--- a/drivers/nvme/host/trace.c
+++ b/drivers/nvme/host/trace.c
@@ -142,3 +142,5 @@ const char *nvme_trace_disk_name(struct trace_seq *p, char *name)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(nvme_trace_disk_name);
+
+EXPORT_TRACEPOINT_SYMBOL(nvme_sq);
diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
index 196d5bd56718..3606cd7000f4 100644
--- a/drivers/nvme/host/trace.h
+++ b/drivers/nvme/host/trace.h
@@ -184,6 +184,27 @@ TRACE_EVENT(nvme_async_event,
 
 #undef aer_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(
+		__assign_disk_name(__entry->disk, rq_disk);
+		__entry->qid = qid;
+		__entry->sq_head = sq_head;
+		__entry->sq_tail = sq_tail;
+	),
+	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
-- 
2.17.1

Re: [PATCH v4 2/2] trace nvme submit queue status

[Sagi Grimberg]

> @@ -899,6 +900,10 @@ 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);

Why the newline escapes? why not escape at the 80 char border?

Other than that, looks fine,

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

Re: [PATCH v4 1/2] export trace.c helper functions to other modules

[Sagi Grimberg]

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

Re: [PATCH v4 2/2] trace nvme submit queue status

[peng yu]

On Mon, Dec 17, 2018 at 11:26 PM Sagi Grimberg <sagi@grimberg.me> wrote:
>
>
> > @@ -899,6 +900,10 @@ 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);
>
> Why the newline escapes? why not escape at the 80 char border?
>

Sorry, I don't quite understand your meaning. Do you mean I'd better
change this:
        trace_nvme_sq(req->rq_disk,
                nvmeq->qid,
                le16_to_cpu(cqe->sq_head),
                nvmeq->sq_tail);
to something like below:
        trace_nvme_sq(req->rq_disk, nvmeq->qid, le16_to_cpu(cqe->sq_head),
                nvmeq->sq_tail);
Please let me know whether my understanding is correct.

Re: [PATCH v4 1/2] export trace.c helper functions to other modules

[Christoph Hellwig]

On Mon, Dec 17, 2018 at 08:51:37PM -0800, yupeng wrote:
> Export bellow three functions:
> nvme_trace_parse_admin_cmd
> nvme_trace_parse_nvm_cmd
> nvme_trace_disk_name
> Thus any other modules which depends on nvme-core could use the trace
> events in trace.h

But we don't actually use these trace events anywhere outside of core.c,
even with your second patch, do we?

Re: [PATCH v4 1/2] export trace.c helper functions to other modules

[Christoph Hellwig]

On Tue, Dec 18, 2018 at 05:57:06PM +0100, Christoph Hellwig wrote:
> 
> 
> On Mon, Dec 17, 2018 at 08:51:37PM -0800, yupeng wrote:
> > Export bellow three functions:
> > nvme_trace_parse_admin_cmd
> > nvme_trace_parse_nvm_cmd
> > nvme_trace_disk_name
> > Thus any other modules which depends on nvme-core could use the trace
> > events in trace.h
> 
> But we don't actually use these trace events anywhere outside of core.c,
> even with your second patch, do we?

Except for nvme_trace_disk_name, which is used via __print_disk_name.

Re: [PATCH v4 2/2] trace nvme submit queue status

[Christoph Hellwig]

On Mon, Dec 17, 2018 at 11:44:51PM -0800, peng yu wrote:
> Sorry, I don't quite understand your meaning. Do you mean I'd better
> change this:
>         trace_nvme_sq(req->rq_disk,
>                 nvmeq->qid,
>                 le16_to_cpu(cqe->sq_head),
>                 nvmeq->sq_tail);
> to something like below:
>         trace_nvme_sq(req->rq_disk, nvmeq->qid, le16_to_cpu(cqe->sq_head),
>                 nvmeq->sq_tail);
> Please let me know whether my understanding is correct.

Yes.  Let me know if this version that I've applied is fine with you:

http://git.infradead.org/nvme.git/commitdiff/ed537628e59166a080d618825a7d175565a9cad4

Re: [PATCH v4 2/2] trace nvme submit queue status

[Keith Busch]

On Mon, Dec 17, 2018 at 08:51:38PM -0800, yupeng wrote:
> +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(
> +		__assign_disk_name(__entry->disk, rq_disk);
> +		__entry->qid = qid;
> +		__entry->sq_head = sq_head;
> +		__entry->sq_tail = sq_tail;
> +	),
> +	TP_printk("nvme: %s qid=%d head=%d tail=%d",
> +		__print_disk_name(__entry->disk),

No need for a space after the %s. __print_disk_name already appends a
space if there's a disk name, and we don't want the extra space if there
isn't one. Also, every other nvme trace has a ',' after each entry. Not
a big deal, just minor format consistency.

Re: [PATCH v4 2/2] trace nvme submit queue status

[hch]

On Tue, Dec 18, 2018 at 10:26:46AM -0700, Keith Busch wrote:
> No need for a space after the %s. __print_disk_name already appends a
> space if there's a disk name, and we don't want the extra space if there
> isn't one. Also, every other nvme trace has a ',' after each entry. Not
> a big deal, just minor format consistency.

Yeah.  What about something like this incremental patch to make the
trace formatting and argument passing match what we otherwise do:

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 2477bd906904..5a0bf6a24d50 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1004,8 +1004,7 @@ 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);
+	trace_nvme_sq(req, cqe->sq_head, nvmeq->sq_tail);
 	nvme_end_request(req, cqe->status, cqe->result);
 }
 
diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
index cf666709bc50..3564120aa7b3 100644
--- a/drivers/nvme/host/trace.h
+++ b/drivers/nvme/host/trace.h
@@ -185,22 +185,24 @@ TRACE_EVENT(nvme_async_event,
 #undef aer_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_PROTO(struct request *req, __le16 sq_head, int sq_tail),
+	TP_ARGS(req, sq_head, sq_tail),
 	TP_STRUCT__entry(
+		__field(int, ctrl_id)
 		__array(char, disk, DISK_NAME_LEN)
 		__field(int, qid)
-		__field(int, sq_head)
-		__field(int, sq_tail)
+		__field(u16, sq_head)
+		__field(u16, sq_tail)
 	),
 	TP_fast_assign(
-		__assign_disk_name(__entry->disk, rq_disk);
-		__entry->qid = qid;
-		__entry->sq_head = sq_head;
+		__entry->ctrl_id = nvme_req(req)->ctrl->instance;
+		__assign_disk_name(__entry->disk, req->rq_disk);
+		__entry->qid = nvme_req_qid(req);
+		__entry->sq_head = le16_to_cpu(sq_head);
 		__entry->sq_tail = sq_tail;
 	),
-	TP_printk("nvme: %s qid=%d head=%d tail=%d",
-		__print_disk_name(__entry->disk),
+	TP_printk("nvme%d: %sqid=%d, head=%u, tail=%u",
+		__entry->ctrl_id, __print_disk_name(__entry->disk),
 		__entry->qid, __entry->sq_head, __entry->sq_tail
 	)
 );

Re: [PATCH v4 2/2] trace nvme submit queue status

[Keith Busch]

On Tue, Dec 18, 2018 at 06:47:50PM +0100, hch@lst.de wrote:
> On Tue, Dec 18, 2018 at 10:26:46AM -0700, Keith Busch wrote:
> > No need for a space after the %s. __print_disk_name already appends a
> > space if there's a disk name, and we don't want the extra space if there
> > isn't one. Also, every other nvme trace has a ',' after each entry. Not
> > a big deal, just minor format consistency.
> 
> Yeah.  What about something like this incremental patch to make the
> trace formatting and argument passing match what we otherwise do:

Nice, that looks good. It's also necessary for admin commands since
there was no other way to see which controller a completion came from
without this.

Reviewed-by: Keith Busch <keith.busch@intel.com> 


> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 2477bd906904..5a0bf6a24d50 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1004,8 +1004,7 @@ 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);
> +	trace_nvme_sq(req, cqe->sq_head, nvmeq->sq_tail);
>  	nvme_end_request(req, cqe->status, cqe->result);
>  }
>  
> diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
> index cf666709bc50..3564120aa7b3 100644
> --- a/drivers/nvme/host/trace.h
> +++ b/drivers/nvme/host/trace.h
> @@ -185,22 +185,24 @@ TRACE_EVENT(nvme_async_event,
>  #undef aer_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_PROTO(struct request *req, __le16 sq_head, int sq_tail),
> +	TP_ARGS(req, sq_head, sq_tail),
>  	TP_STRUCT__entry(
> +		__field(int, ctrl_id)
>  		__array(char, disk, DISK_NAME_LEN)
>  		__field(int, qid)
> -		__field(int, sq_head)
> -		__field(int, sq_tail)
> +		__field(u16, sq_head)
> +		__field(u16, sq_tail)
>  	),
>  	TP_fast_assign(
> -		__assign_disk_name(__entry->disk, rq_disk);
> -		__entry->qid = qid;
> -		__entry->sq_head = sq_head;
> +		__entry->ctrl_id = nvme_req(req)->ctrl->instance;
> +		__assign_disk_name(__entry->disk, req->rq_disk);
> +		__entry->qid = nvme_req_qid(req);
> +		__entry->sq_head = le16_to_cpu(sq_head);
>  		__entry->sq_tail = sq_tail;
>  	),
> -	TP_printk("nvme: %s qid=%d head=%d tail=%d",
> -		__print_disk_name(__entry->disk),
> +	TP_printk("nvme%d: %sqid=%d, head=%u, tail=%u",
> +		__entry->ctrl_id, __print_disk_name(__entry->disk),
>  		__entry->qid, __entry->sq_head, __entry->sq_tail
>  	)
>  );

Re: [PATCH v4 2/2] trace nvme submit queue status

[peng yu]

On Tue, Dec 18, 2018 at 9:47 AM hch@lst.de <hch@lst.de> wrote:
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 2477bd906904..5a0bf6a24d50 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1004,8 +1004,7 @@ 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);
> +       trace_nvme_sq(req, cqe->sq_head, nvmeq->sq_tail);
>         nvme_end_request(req, cqe->status, cqe->result);
>  }
>
> diff --git a/drivers/nvme/host/trace.h b/drivers/nvme/host/trace.h
> index cf666709bc50..3564120aa7b3 100644
> --- a/drivers/nvme/host/trace.h
> +++ b/drivers/nvme/host/trace.h
> @@ -185,22 +185,24 @@ TRACE_EVENT(nvme_async_event,
>  #undef aer_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_PROTO(struct request *req, __le16 sq_head, int sq_tail),
> +       TP_ARGS(req, sq_head, sq_tail),
>         TP_STRUCT__entry(
> +               __field(int, ctrl_id)
>                 __array(char, disk, DISK_NAME_LEN)
>                 __field(int, qid)
> -               __field(int, sq_head)
> -               __field(int, sq_tail)
> +               __field(u16, sq_head)
> +               __field(u16, sq_tail)
>         ),
>         TP_fast_assign(
> -               __assign_disk_name(__entry->disk, rq_disk);
> -               __entry->qid = qid;
> -               __entry->sq_head = sq_head;
> +               __entry->ctrl_id = nvme_req(req)->ctrl->instance;
> +               __assign_disk_name(__entry->disk, req->rq_disk);
> +               __entry->qid = nvme_req_qid(req);
> +               __entry->sq_head = le16_to_cpu(sq_head);
>                 __entry->sq_tail = sq_tail;
>         ),
> -       TP_printk("nvme: %s qid=%d head=%d tail=%d",
> -               __print_disk_name(__entry->disk),
> +       TP_printk("nvme%d: %sqid=%d, head=%u, tail=%u",
> +               __entry->ctrl_id, __print_disk_name(__entry->disk),
>                 __entry->qid, __entry->sq_head, __entry->sq_tail
>         )
>  );

I think this change is nice. Will you submit this change or are you
suggesting me to do it?

Re: [PATCH v4 2/2] trace nvme submit queue status

[hch]

On Tue, Dec 18, 2018 at 05:19:00PM -0800, peng yu wrote:
> I think this change is nice. Will you submit this change or are you
> suggesting me to do it?

I've folded the changes in.