new file mode 100644
@@ -0,0 +1,38 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM tcp
+
+#if !defined(_TRACE_TCP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_TCP_H
+
+#include <linux/skbuff.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(tcp_retransmit_skb,
+
+ TP_PROTO(struct sock *sk, struct sk_buff *skb, int err),
+
+ TP_ARGS(sk, skb, err),
+
+ TP_STRUCT__entry(
+ __field(void *, skaddr)
+ __field(void *, skbaddr)
+ __field(__u16, lport)
+ __field(int, err)
+ ),
+
+ TP_fast_assign(
+ __entry->skaddr = sk;
+ __entry->skbaddr = skb;
+ __entry->lport = inet_sk(sk)->inet_num;
+ __entry->err = err;
+ ),
+
+ TP_printk("sk=%p skb=%p port=%hu err=%d",
+ __entry->skaddr, __entry->skbaddr,
+ __entry->lport, __entry->err)
+);
+
+#endif /* _TRACE_TCP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
@@ -31,6 +31,7 @@
#include <trace/events/napi.h>
#include <trace/events/sock.h>
#include <trace/events/udp.h>
+#include <trace/events/tcp.h>
EXPORT_TRACEPOINT_SYMBOL_GPL(kfree_skb);
@@ -40,6 +40,8 @@
#include <linux/gfp.h>
#include <linux/module.h>
+#include <trace/events/tcp.h>
+
/* People can turn this off for buggy TCP's found in printers etc. */
int sysctl_tcp_retrans_collapse __read_mostly = 1;
@@ -2199,6 +2201,7 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
TCP_SKB_CB(skb)->ack_seq = tp->snd_nxt;
}
out:
+ trace_tcp_retransmit_skb(sk, skb, err);
return err;
}
This patch adds a tracepoint to tcp_retransmit_skb() to get the pointer to sk and skb, local port number and return value. This helps one understand whether problems are in a server or not. Signed-off-by: Satoru Moriya <satoru.moriya@hds.com> --- include/trace/events/tcp.h | 38 ++++++++++++++++++++++++++++++++++++++ net/core/net-traces.c | 1 + net/ipv4/tcp_output.c | 3 +++ 3 files changed, 42 insertions(+), 0 deletions(-) create mode 100644 include/trace/events/tcp.h