[RFC PATCH v2 4/5] skb: add tracepoints to freeing skb
From: Koki Sanagi <hidden>
Date: 2010-06-24 08:19:43
Subsystem:
networking [general], the rest, tracing · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
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 <redacted>
---
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) +); + 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);