skb: add tracepoints to freeing skb
in [Kernel]
|
Prev: [PATCH] staging/spectra: remove non existing blk_fs_request wrapper
Next: [RFC] [PATCH v3 0/2] cgroups: implement moving a threadgroup's threads atomically with cgroup.procs
From: Neil Horman on 21 Jul 2010 07:00 On Wed, Jul 21, 2010 at 04:02:57PM +0900, Koki Sanagi wrote: > (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. > It isn't, you're right, but that was the point I made above. Those missed areas could be easily handled by adding calls to trace_kfree_skb which already exists, to the missed areas. Then you don't need to create those new tracepoints. The way your doing this, if someone wants to trace all skb frees in debugfs, they would have to enable three tracepoints, not just one. Not that thats the point of your patch, but its something to consider, and it simplifies your code. Neil > 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/
From: Koki Sanagi on 22 Jul 2010 04:40 (2010/07/21 19:56), Neil Horman wrote: > On Wed, Jul 21, 2010 at 04:02:57PM +0900, Koki Sanagi wrote: >> (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. >> > It isn't, you're right, but that was the point I made above. Those missed areas > could be easily handled by adding calls to trace_kfree_skb which already exists, > to the missed areas. Then you don't need to create those new tracepoints. The > way your doing this, if someone wants to trace all skb frees in debugfs, they > would have to enable three tracepoints, not just one. Not that thats the point > of your patch, but its something to consider, and it simplifies your code. > Neil > O.K. I've re-made a patch to use trace_kfree_skb instead of trace_dev_kfree_skb_irq and trace_skb_free_datagram_locked. But I've got a problem. I should use not __builtin_return_address, but macro or function which returns current address. But I don't know any macro like that. Do you know any solution ? Koki Sanagi. --- include/trace/events/skb.h | 17 +++++++++++++++++ net/core/datagram.c | 1 + net/core/dev.c | 2 ++ net/core/skbuff.c | 1 + 4 files changed, 21 insertions(+), 0 deletions(-) diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 4b2be6d..75ce9d5 100644 --- a/include/trace/events/skb.h +++ b/include/trace/events/skb.h @@ -35,6 +35,23 @@ 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(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 251997a..96dab4f 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -243,6 +243,7 @@ void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) unlock_sock_fast(sk, slow); /* skb is now orphaned, can be freed outside of locked section */ + trace_kfree_skb(skb, __builtin_return_address(0)); __kfree_skb(skb); } EXPORT_SYMBOL(skb_free_datagram_locked); diff --git a/net/core/dev.c b/net/core/dev.c index e6a911f..faded6f 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" @@ -2577,6 +2578,7 @@ static void net_tx_action(struct softirq_action *h) clist = clist->next; WARN_ON(atomic_read(&skb->users)); + trace_kfree_skb(skb, __builtin_return_address(0)); __kfree_skb(skb); } } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 76d33ca..ce0bc36 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/
From: Neil Horman on 22 Jul 2010 11:10
On Thu, Jul 22, 2010 at 05:39:15PM +0900, Koki Sanagi wrote: > (2010/07/21 19:56), Neil Horman wrote: > > On Wed, Jul 21, 2010 at 04:02:57PM +0900, Koki Sanagi wrote: > >> (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. > >> > > It isn't, you're right, but that was the point I made above. Those missed areas > > could be easily handled by adding calls to trace_kfree_skb which already exists, > > to the missed areas. Then you don't need to create those new tracepoints. The > > way your doing this, if someone wants to trace all skb frees in debugfs, they > > would have to enable three tracepoints, not just one. Not that thats the point > > of your patch, but its something to consider, and it simplifies your code. > > Neil > > > > O.K. I've re-made a patch to use trace_kfree_skb instead of > trace_dev_kfree_skb_irq and trace_skb_free_datagram_locked. > But I've got a problem. > I should use not __builtin_return_address, but macro or function which returns > current address. But I don't know any macro like that. Do you know any solution ? > Since the trace call is the first thing in the function, why not just pass in skb_free_datagram_locked as the pointer. That should work out properly 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/ |