[RFC PATCH v3 4/5] skb: add tracepoints to freeing skb
From: Koki Sanagi <hidden>
Date: 2010-07-20 00:49:25
Also in:
lkml
Subsystem:
networking [general], the rest, tracing · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
[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 <redacted>
---
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); 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; + trace_consume_skb(skb); __kfree_skb(skb); } EXPORT_SYMBOL(consume_skb);