Messages in this thread | | | Date | Tue, 20 Jul 2010 07:50:44 -0400 | From | Neil Horman <> | Subject | Re: [RFC PATCH v3 4/5] skb: add tracepoints to freeing skb |
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On Tue, Jul 20, 2010 at 09:49:10AM +0900, Koki Sanagi wrote: > [RFC PATCH v3 4/5] skb: add tracepoints to freeing skb > This patch adds tracepoint to consume_skb, dev_kfree_skb_irq and > skb_free_datagram_locked. Combinating with tracepoint on dev_hard_start_xmit, > we can check how long it takes to free transmited packets. And using it, we can > calculate how many packets driver had at that time. It is useful when a drop of > transmited packet is a problem. > > <idle>-0 [001] 241409.218333: consume_skb: skbaddr=dd6b2fb8 > <idle>-0 [001] 241409.490555: dev_kfree_skb_irq: skbaddr=f5e29840 > > udp-recv-302 [001] 515031.206008: skb_free_datagram_locked: skbaddr=f5b1d900 > > > Signed-off-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com> > --- > include/trace/events/skb.h | 42 ++++++++++++++++++++++++++++++++++++++++++ > net/core/datagram.c | 1 + > net/core/dev.c | 2 ++ > net/core/skbuff.c | 1 + > 4 files changed, 46 insertions(+), 0 deletions(-) > > diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h > index 4b2be6d..84c9041 100644 > --- a/include/trace/events/skb.h > +++ b/include/trace/events/skb.h > @@ -35,6 +35,48 @@ TRACE_EVENT(kfree_skb, > __entry->skbaddr, __entry->protocol, __entry->location) > ); > > +DECLARE_EVENT_CLASS(free_skb, > + > + TP_PROTO(struct sk_buff *skb), > + > + TP_ARGS(skb), > + > + TP_STRUCT__entry( > + __field( void *, skbaddr ) > + ), > + > + TP_fast_assign( > + __entry->skbaddr = skb; > + ), > + > + TP_printk("skbaddr=%p", __entry->skbaddr) > + > +); > + > +DEFINE_EVENT(free_skb, consume_skb, > + > + TP_PROTO(struct sk_buff *skb), > + > + TP_ARGS(skb) > + > +); > + > +DEFINE_EVENT(free_skb, dev_kfree_skb_irq, > + > + TP_PROTO(struct sk_buff *skb), > + > + TP_ARGS(skb) > + > +); > + > +DEFINE_EVENT(free_skb, skb_free_datagram_locked, > + > + TP_PROTO(struct sk_buff *skb), > + > + TP_ARGS(skb) > + > +); > +
Why create these last two tracepoints at all? dev_kfree_skb_irq will eventually pass through kfree_skb anyway, getting picked up by the tracepoint there, the while the latter won't (since it uses __kfree_skb instead), I think that could be fixed up by add a call to trace_kfree_skb there directly, saving you two tracepoints.
Neil
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