[PATCH 1/2] nvme: add tracepoint for nvme_setup_cmd

Hannes Reinecke hare at suse.de
Tue Jan 16 03:27:33 PST 2018


On 01/16/2018 11:34 AM, Johannes Thumshirn wrote:
> Signed-off-by: Johannes Thumshirn <jthumshirn at suse.de>
> ---
>  drivers/nvme/host/core.c    | 69 +++++++++++++++++++++++++++++++++++++++++++++
>  include/trace/events/nvme.h | 64 +++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 133 insertions(+)
>  create mode 100644 include/trace/events/nvme.h
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 839650e0926a..4b6a56fe6ccf 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -29,6 +29,9 @@
>  #include <linux/pm_qos.h>
>  #include <asm/unaligned.h>
>  
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/nvme.h>
> +
>  #include "nvme.h"
>  #include "fabrics.h"
>  
> @@ -80,6 +83,71 @@ static struct class *nvme_subsys_class;
>  static void nvme_ns_remove(struct nvme_ns *ns);
>  static int nvme_revalidate_disk(struct gendisk *disk);
>  
> +static const char *nvme_trace_read_write(struct trace_seq *p,
> +					 struct nvme_rw_command rw)
> +{
> +	const char *ret = trace_seq_buffer_ptr(p);
> +
> +	trace_seq_printf(p, "slba=%llu, length=%u, control=0x%x, dsmgmt=%u, reftag=%u",
> +			 (unsigned long long)le64_to_cpu(rw.slba),
> +			 le16_to_cpu(rw.length), le16_to_cpu(rw.control),
> +			 le32_to_cpu(rw.dsmgmt), le32_to_cpu(rw.reftag));
> +	trace_seq_putc(p, 0);
> +
> +	return ret;
> +}
> +
> +static const char *nvme_trace_dsm(struct trace_seq *p, struct nvme_dsm_cmd dsm)
> +{
> +	const char *ret = trace_seq_buffer_ptr(p);
> +
> +	trace_seq_printf(p, "nr=%u, attributes=%u",
> +			 le32_to_cpu(dsm.nr), le32_to_cpu(dsm.attributes));
> +	trace_seq_putc(p, 0);
> +
> +	return ret;
> +}
> +
> +static const char *nvme_trace_write_zeroes(struct trace_seq *p,
> +					   struct nvme_write_zeroes_cmd wz)
> +{
> +	const char *ret = trace_seq_buffer_ptr(p);
> +
> +	trace_seq_printf(p, "slba=%llu, length=%u, control=%u, dsmgmt=%u, reftag=%u",
> +			 (unsigned long long) le64_to_cpu(wz.slba),
> +			 le16_to_cpu(wz.length), le16_to_cpu(wz.control),
> +			 le32_to_cpu(wz.dsmgmt), le32_to_cpu(wz.reftag));
> +	trace_seq_putc(p, 0);
> +
> +	return ret;
> +}
> +
> +static const char *nvme_trace_common(struct trace_seq *p,
> +				     struct nvme_common_command c)
> +{
> +	const char *ret = trace_seq_buffer_ptr(p);
> +
> +	trace_seq_printf(p, "cdw2=%*ph, cdw10=%*ph", 4, c.cdw2, 24, c.cdw10);
> +	trace_seq_putc(p, 0);
> +
> +	return ret;
> +}
> +
> +const char *nvme_trace_parse_cmd(struct trace_seq *p, struct nvme_command cmd)
> +{
> +	switch (cmd.common.opcode) {
> +	case nvme_cmd_read:
> +	case nvme_cmd_write:
> +		return nvme_trace_read_write(p, cmd.rw);
> +	case nvme_cmd_dsm:
> +		return nvme_trace_dsm(p, cmd.dsm);
> +	case nvme_cmd_write_zeroes:
> +		return nvme_trace_write_zeroes(p, cmd.write_zeroes);
> +	default:
> +		return nvme_trace_common(p, cmd.common);
> +	}
> +}
> +
>  static __le32 nvme_get_log_dw10(u8 lid, size_t size)
>  {
>  	return cpu_to_le32((((size / 4) - 1) << 16) | lid);
> @@ -591,6 +659,7 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
>  	}
>  
>  	cmd->common.command_id = req->tag;
> +	trace_nvme_setup_cmd(cmd);
>  	return ret;
>  }
>  EXPORT_SYMBOL_GPL(nvme_setup_cmd);
> diff --git a/include/trace/events/nvme.h b/include/trace/events/nvme.h
> new file mode 100644
> index 000000000000..2e93bc7d4f84
> --- /dev/null
> +++ b/include/trace/events/nvme.h
> @@ -0,0 +1,64 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#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>
> +
> +#define nvme_opcode_name(opcode)	{ opcode, #opcode }
> +#define show_opcode_name(val)					\
> +	__print_symbolic(val,					\
> +		nvme_opcode_name(nvme_cmd_flush),		\
> +		nvme_opcode_name(nvme_cmd_write),		\
> +		nvme_opcode_name(nvme_cmd_read),		\
> +		nvme_opcode_name(nvme_cmd_write_uncor),		\
> +		nvme_opcode_name(nvme_cmd_compare),		\
> +		nvme_opcode_name(nvme_cmd_write_zeroes),	\
> +		nvme_opcode_name(nvme_cmd_dsm),			\
> +		nvme_opcode_name(nvme_cmd_resv_register),	\
> +		nvme_opcode_name(nvme_cmd_resv_report),		\
> +		nvme_opcode_name(nvme_cmd_resv_acquire),	\
> +		nvme_opcode_name(nvme_cmd_resv_release))
> +
> +const char *nvme_trace_parse_cmd(struct trace_seq *p, struct nvme_command cmnd);
> +#define __parse_nvme_cmd(cmd) nvme_trace_parse_cmd(p, cmd)
> +
> +TRACE_EVENT(nvme_setup_cmd,
> +
> +	    TP_PROTO(struct nvme_command *cmd),
> +
> +	    TP_ARGS(cmd),
> +
> +	    TP_STRUCT__entry(
> +		    __field( __u8,                opcode   )
> +		    __field( __u8,                flags    )
> +		    __field( __u16,               cid      )
> +		    __field( __le32,              nsid     )
> +		    __field( __le64,              metadata )
> +		    __field_struct( struct nvme_command, cmnd )
> +	    ),
> +
> +	    TP_fast_assign(
> +		    __entry->opcode	= cmd->common.opcode;
> +		    __entry->flags	= cmd->common.flags;
> +		    __entry->cid	= cmd->common.command_id;
> +		    __entry->nsid	= cmd->common.nsid;
> +		    __entry->metadata	= cmd->common.metadata;
> +		    memcpy(&__entry->cmnd, cmd, sizeof(__entry->cmnd));
> +	    ),
> +
> +	    TP_printk("nsid=%u, command_id=%u, flags=0x%x, metadata=0x%llx, cmd=(%s %s)",
> +		      le32_to_cpu(__entry->nsid), __entry->cid, __entry->flags,
> +		      (unsigned long long) le64_to_cpu(__entry->metadata),
> +		      show_opcode_name(__entry->opcode),
> +		      __parse_nvme_cmd(__entry->cmnd))
> +);
> +
> +#endif /* _TRACE_NVME_H */
> +
> +/* This part must be boutside protection */
> +#include <trace/define_trace.h>
> 
'boutside proctetion'?

In general I'd rather have the tracepoints when actually submitting the
request; with this tracepoint we might be getting a trace which doesn't
really indicate if the command was submitted at all.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare at suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)



More information about the Linux-nvme mailing list