Commit 07dc22e7 authored by Koki Sanagi's avatar Koki Sanagi Committed by Frederic Weisbecker

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: default avatarKoki Sanagi <sanagi.koki@jp.fujitsu.com>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Kaneshige Kenji <kaneshige.kenji@jp.fujitsu.com>
Cc: Izumo Taku <izumi.taku@jp.fujitsu.com>
Cc: Kosaki Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Scott Mcmillan <scott.a.mcmillan@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
LKML-Reference: <4C724364.50903@jp.fujitsu.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent cf66ba58
...@@ -35,6 +35,23 @@ TRACE_EVENT(kfree_skb, ...@@ -35,6 +35,23 @@ TRACE_EVENT(kfree_skb,
__entry->skbaddr, __entry->protocol, __entry->location) __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, TRACE_EVENT(skb_copy_datagram_iovec,
TP_PROTO(const struct sk_buff *skb, int len), TP_PROTO(const struct sk_buff *skb, int len),
......
...@@ -243,6 +243,7 @@ void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) ...@@ -243,6 +243,7 @@ void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb)
unlock_sock_fast(sk, slow); unlock_sock_fast(sk, slow);
/* skb is now orphaned, can be freed outside of locked section */ /* skb is now orphaned, can be freed outside of locked section */
trace_kfree_skb(skb, skb_free_datagram_locked);
__kfree_skb(skb); __kfree_skb(skb);
} }
EXPORT_SYMBOL(skb_free_datagram_locked); EXPORT_SYMBOL(skb_free_datagram_locked);
......
...@@ -129,6 +129,7 @@ ...@@ -129,6 +129,7 @@
#include <linux/random.h> #include <linux/random.h>
#include <trace/events/napi.h> #include <trace/events/napi.h>
#include <trace/events/net.h> #include <trace/events/net.h>
#include <trace/events/skb.h>
#include <linux/pci.h> #include <linux/pci.h>
#include "net-sysfs.h" #include "net-sysfs.h"
...@@ -2576,6 +2577,7 @@ static void net_tx_action(struct softirq_action *h) ...@@ -2576,6 +2577,7 @@ static void net_tx_action(struct softirq_action *h)
clist = clist->next; clist = clist->next;
WARN_ON(atomic_read(&skb->users)); WARN_ON(atomic_read(&skb->users));
trace_kfree_skb(skb, net_tx_action);
__kfree_skb(skb); __kfree_skb(skb);
} }
} }
......
...@@ -466,6 +466,7 @@ void consume_skb(struct sk_buff *skb) ...@@ -466,6 +466,7 @@ void consume_skb(struct sk_buff *skb)
smp_rmb(); smp_rmb();
else if (likely(!atomic_dec_and_test(&skb->users))) else if (likely(!atomic_dec_and_test(&skb->users)))
return; return;
trace_consume_skb(skb);
__kfree_skb(skb); __kfree_skb(skb);
} }
EXPORT_SYMBOL(consume_skb); EXPORT_SYMBOL(consume_skb);
......
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