Re: [RFC PATCH v2 3/5] netdev: add tracepoints to netdev layer

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 2010-06-25 at 09:58 +0900, Koki Sanagi wrote:
> This patch adds tracepoint to dev_queue_xmit, dev_hard_start_xmit and
> netif_receive_skb. These tracepints help you to monitor network driver's
> input/output.
> 
>             sshd-4445  [001] 241367.066046: net_dev_queue: dev=eth3 skbaddr=dd6b2538 len=114
>             sshd-4445  [001] 241367.066047: net_dev_xmit: dev=eth3 skbaddr=dd6b2538 len=114 rc=0
>           <idle>-0     [001] 241367.067472: net_dev_receive: dev=eth3 skbaddr=f5e59000 len=52
> 
> Signed-off-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
> ---
>  include/trace/events/net.h |   83 ++++++++++++++++++++++++++++++++++++++++++++
>  net/core/dev.c             |    5 +++
>  net/core/net-traces.c      |    1 +
>  3 files changed, 89 insertions(+), 0 deletions(-)
> 
> diff --git a/include/trace/events/net.h b/include/trace/events/net.h
> new file mode 100644
> index 0000000..ee10970
> --- /dev/null
> +++ b/include/trace/events/net.h
> @@ -0,0 +1,83 @@
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM net
> +
> +#if !defined(_TRACE_NET_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_NET_H
> +
> +#include <linux/skbuff.h>
> +#include <linux/netdevice.h>
> +#include <linux/ip.h>
> +#include <linux/tracepoint.h>
> +
> +TRACE_EVENT(net_dev_xmit,
> +
> +	TP_PROTO(struct sk_buff *skb,
> +		 int rc),
> +
> +	TP_ARGS(skb, rc),
> +
> +	TP_STRUCT__entry(
> +		__field(	void *,		skbaddr		)
> +		__field(	unsigned int,	len		)
> +		__field(	int,		rc		)
> +		__string(	name,		skb->dev->name	)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->skbaddr = skb;
> +		__entry->len = skb->len;
> +		__entry->rc = rc;
> +		__assign_str(name, skb->dev->name);
> +	),
> +
> +	TP_printk("dev=%s skbaddr=%p len=%u rc=%d",
> +		__get_str(name), __entry->skbaddr, __entry->len, __entry->rc)
> +);
> +
> +TRACE_EVENT(net_dev_queue,
> +
> +	TP_PROTO(struct sk_buff *skb),
> +
> +	TP_ARGS(skb),
> +
> +	TP_STRUCT__entry(
> +		__field(	void *,		skbaddr		)
> +		__field(	unsigned int,	len		)
> +		__string(	name,		skb->dev->name	)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->skbaddr = skb;
> +		__entry->len = skb->len;
> +		__assign_str(name, skb->dev->name);
> +	),
> +
> +	TP_printk("dev=%s skbaddr=%p len=%u",
> +		__get_str(name), __entry->skbaddr, __entry->len)
> +);
> +
> +TRACE_EVENT(net_dev_receive,

This and net_dev_queue are identical. Please use DECLARE_EVENT_CLASS()
and DEFINE_EVENT() to create these, otherwise it bloats the kernel.

-- Steve

> +
> +	TP_PROTO(struct sk_buff *skb),
> +
> +	TP_ARGS(skb),
> +
> +	TP_STRUCT__entry(
> +		__field(	void *,		skbaddr		)
> +		__field(	unsigned int,	len		)
> +		__string(	name,		skb->dev->name	)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->skbaddr = skb;
> +		__entry->len = skb->len;
> +		__assign_str(name, skb->dev->name);
> +	),
> +
> +	TP_printk("dev=%s skbaddr=%p len=%u",
> +		__get_str(name), __entry->skbaddr, __entry->len)
> +);
> +#endif /* _TRACE_NET_H */
> +