skb: add tracepoints to freeing skb
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From: Koki Sanagi on 28 Jun 2010 20:30 (2010/06/29 3:12), Steven Rostedt wrote: > On Fri, 2010-06-25 at 09:59 +0900, Koki Sanagi wrote: >> This patch adds tracepoint to consume_skb and dev_kfree_skb_irq. >> 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 >> >> Signed-off-by: Koki Sanagi <sanagi.koki(a)jp.fujitsu.com> >> --- >> include/trace/events/skb.h | 36 ++++++++++++++++++++++++++++++++++++ >> net/core/dev.c | 2 ++ >> net/core/skbuff.c | 1 + >> 3 files changed, 39 insertions(+), 0 deletions(-) >> >> diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h >> index 4b2be6d..6ab5b34 100644 >> --- a/include/trace/events/skb.h >> +++ b/include/trace/events/skb.h >> @@ -35,6 +35,42 @@ TRACE_EVENT(kfree_skb, >> __entry->skbaddr, __entry->protocol, __entry->location) >> ); >> >> +TRACE_EVENT(consume_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) >> +); >> + >> +TRACE_EVENT(dev_kfree_skb_irq, >> + >> + 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) >> +); > > These two tracepoints are also identical in body. Please use > DECLARE_EVENT_CLASS() and DEFINE_EVENT() instead. > > -- Steve > OK, I'll do that. Thanks, Koki Sanagi. >> + >> TRACE_EVENT(skb_copy_datagram_iovec, >> >> TP_PROTO(const struct sk_buff *skb, int len), >> diff --git a/net/core/dev.c b/net/core/dev.c >> index 4b64b21..807b1ca 100644 >> --- a/net/core/dev.c >> +++ b/net/core/dev.c >> @@ -131,6 +131,7 @@ >> #include <linux/random.h> >> #include <trace/events/napi.h> >> #include <trace/events/net.h> >> +#include <trace/events/skb.h> >> #include <linux/pci.h> >> >> #include "net-sysfs.h" >> @@ -1580,6 +1581,7 @@ void dev_kfree_skb_irq(struct sk_buff *skb) >> struct softnet_data *sd; >> unsigned long flags; >> >> + trace_dev_kfree_skb_irq(skb); >> local_irq_save(flags); >> sd = &__get_cpu_var(softnet_data); >> skb->next = sd->completion_queue; >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c >> index 34432b4..a7b4036 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -466,6 +466,7 @@ void consume_skb(struct sk_buff *skb) >> smp_rmb(); >> else if (likely(!atomic_dec_and_test(&skb->users))) >> return; >> + trace_consume_skb(skb); >> __kfree_skb(skb); >> } >> EXPORT_SYMBOL(consume_skb); >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo(a)vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Eric Dumazet on 20 Jul 2010 01:00 Le mardi 20 juillet 2010 à 09:49 +0900, Koki Sanagi a écrit : > [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(a)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) > + > +); > + > TRACE_EVENT(skb_copy_datagram_iovec, > > TP_PROTO(const struct sk_buff *skb, int len), > diff --git a/net/core/datagram.c b/net/core/datagram.c > index f5b6f43..1ea32a0 100644 > --- a/net/core/datagram.c > +++ b/net/core/datagram.c > @@ -231,6 +231,7 @@ void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) > { > bool slow; > > + trace_skb_free_datagram_locked(skb); Here you unconditionally trace before the test on skb->users > if (likely(atomic_read(&skb->users) == 1)) > smp_rmb(); > else if (likely(!atomic_dec_and_test(&skb->users))) > diff --git a/net/core/dev.c b/net/core/dev.c > index 4acfec6..d979847 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -131,6 +131,7 @@ > #include <linux/random.h> > #include <trace/events/napi.h> > #include <trace/events/net.h> > +#include <trace/events/skb.h> > #include <linux/pci.h> > > #include "net-sysfs.h" > @@ -1581,6 +1582,7 @@ void dev_kfree_skb_irq(struct sk_buff *skb) > struct softnet_data *sd; > unsigned long flags; > > + trace_dev_kfree_skb_irq(skb); > local_irq_save(flags); > sd = &__get_cpu_var(softnet_data); > skb->next = sd->completion_queue; > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 34432b4..a7b4036 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -466,6 +466,7 @@ void consume_skb(struct sk_buff *skb) > smp_rmb(); > else if (likely(!atomic_dec_and_test(&skb->users))) > return; While here you trace _after_ the test on skb->users - and a "return;" , so you miss some consume_skb() calls > + trace_consume_skb(skb); > __kfree_skb(skb); > } > EXPORT_SYMBOL(consume_skb); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Koki Sanagi on 20 Jul 2010 02:50 (2010/07/20 13:54), Eric Dumazet wrote: > Le mardi 20 juillet 2010 à 09:49 +0900, Koki Sanagi a écrit : >> [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(a)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) >> + >> +); >> + >> TRACE_EVENT(skb_copy_datagram_iovec, >> >> TP_PROTO(const struct sk_buff *skb, int len), >> diff --git a/net/core/datagram.c b/net/core/datagram.c >> index f5b6f43..1ea32a0 100644 >> --- a/net/core/datagram.c >> +++ b/net/core/datagram.c >> @@ -231,6 +231,7 @@ void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) >> { >> bool slow; >> >> + trace_skb_free_datagram_locked(skb); > > Here you unconditionally trace before the test on skb->users > >> if (likely(atomic_read(&skb->users) == 1)) >> smp_rmb(); >> else if (likely(!atomic_dec_and_test(&skb->users))) >> diff --git a/net/core/dev.c b/net/core/dev.c >> index 4acfec6..d979847 100644 >> --- a/net/core/dev.c >> +++ b/net/core/dev.c >> @@ -131,6 +131,7 @@ >> #include <linux/random.h> >> #include <trace/events/napi.h> >> #include <trace/events/net.h> >> +#include <trace/events/skb.h> >> #include <linux/pci.h> >> >> #include "net-sysfs.h" >> @@ -1581,6 +1582,7 @@ void dev_kfree_skb_irq(struct sk_buff *skb) >> struct softnet_data *sd; >> unsigned long flags; >> >> + trace_dev_kfree_skb_irq(skb); >> local_irq_save(flags); >> sd = &__get_cpu_var(softnet_data); >> skb->next = sd->completion_queue; >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c >> index 34432b4..a7b4036 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -466,6 +466,7 @@ void consume_skb(struct sk_buff *skb) >> smp_rmb(); >> else if (likely(!atomic_dec_and_test(&skb->users))) >> return; > > While here you trace _after_ the test on skb->users - and a "return;" , > so you miss some consume_skb() calls > Yeah, I'll move trace_consume_skb() before the test. Thanks, Koki Sanagi. > >> + trace_consume_skb(skb); >> __kfree_skb(skb); >> } >> EXPORT_SYMBOL(consume_skb); >> > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Neil Horman on 20 Jul 2010 08:00 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(a)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 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Koki Sanagi on 21 Jul 2010 03:10
(2010/07/20 20:50), Neil Horman wrote: > 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(a)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 > I think dev_kfree_skb_irq isn't chased by trace_kfree_skb or trace_consume_skb completely. Because net_tx_action frees skb by __kfree_skb. So it is better to add trace_kfree_skb before it. skb_free_datagram_locked is same. Thanks, Koki Sanagi. >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |