From 07dc22e7295f25526f110d704655ff0ea7687420 Mon Sep 17 00:00:00 2001 From: Koki Sanagi Date: Mon, 23 Aug 2010 18:46:12 +0900 Subject: [PATCH] skb: Add tracepoints to freeing skb This patch adds tracepoint to consume_skb and add trace_kfree_skb before __kfree_skb in skb_free_datagram_locked and net_tx_action. Combinating with tracepoint on dev_hard_start_xmit, we can check how long it takes to free transmitted packets. And using it, we can calculate how many packets driver had at that time. It is useful when a drop of transmitted packet is a problem. sshd-6828 [000] 112689.258154: consume_skb: skbaddr=f2d99bb8 Signed-off-by: Koki Sanagi Acked-by: David S. Miller Acked-by: Neil Horman Cc: Mathieu Desnoyers Cc: Kaneshige Kenji Cc: Izumo Taku Cc: Kosaki Motohiro Cc: Lai Jiangshan Cc: Scott Mcmillan Cc: Steven Rostedt Cc: Eric Dumazet LKML-Reference: <4C724364.50903@jp.fujitsu.com> Signed-off-by: Frederic Weisbecker --- 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(+) diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h index 4b2be6dc76f0..75ce9d500d8e 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 251997a95483..282806ba7a57 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, skb_free_datagram_locked); __kfree_skb(skb); } EXPORT_SYMBOL(skb_free_datagram_locked); diff --git a/net/core/dev.c b/net/core/dev.c index 5a4fbc7405e2..2308cce48048 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -129,6 +129,7 @@ #include #include #include +#include #include #include "net-sysfs.h" @@ -2576,6 +2577,7 @@ static void net_tx_action(struct softirq_action *h) clist = clist->next; WARN_ON(atomic_read(&skb->users)); + trace_kfree_skb(skb, net_tx_action); __kfree_skb(skb); } } diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 3a2513f0d0c3..12e61e351d0e 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); -- 2.30.2