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authorSatoru Moriya <satoru.moriya@hds.com>2011-06-17 15:58:39 +0400
committerDavid S. Miller <davem@davemloft.net>2011-06-22 03:06:10 +0400
commit296f7ea75b45913d5e2067baef0812087e0b6eb9 (patch)
tree94a5774a525ebb388306a4ae2aef90a0706031f4
parentdec17b74516bb780de75b41e7cfa0072df16bb82 (diff)
downloadlinux-296f7ea75b45913d5e2067baef0812087e0b6eb9.tar.xz
udp: add tracepoints for queueing skb to rcvbuf
This patch adds a tracepoint to __udp_queue_rcv_skb to get the return value of ip_queue_rcv_skb. It indicates why kernel drops a packet at this point. ip_queue_rcv_skb returns following values in the packet drop case: rcvbuf is full : -ENOMEM sk_filter returns error : -EINVAL, -EACCESS, -ENOMEM, etc. __sk_mem_schedule returns error: -ENOBUF Signed-off-by: Satoru Moriya <satoru.moriya@hds.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/trace/events/udp.h32
-rw-r--r--net/core/net-traces.c1
-rw-r--r--net/ipv4/udp.c2
3 files changed, 35 insertions, 0 deletions
diff --git a/include/trace/events/udp.h b/include/trace/events/udp.h
new file mode 100644
index 000000000000..a664bb940973
--- /dev/null
+++ b/include/trace/events/udp.h
@@ -0,0 +1,32 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM udp
+
+#if !defined(_TRACE_UDP_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_UDP_H
+
+#include <linux/udp.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(udp_fail_queue_rcv_skb,
+
+ TP_PROTO(int rc, struct sock *sk),
+
+ TP_ARGS(rc, sk),
+
+ TP_STRUCT__entry(
+ __field(int, rc)
+ __field(__u16, lport)
+ ),
+
+ TP_fast_assign(
+ __entry->rc = rc;
+ __entry->lport = inet_sk(sk)->inet_num;
+ ),
+
+ TP_printk("rc=%d port=%hu", __entry->rc, __entry->lport)
+);
+
+#endif /* _TRACE_UDP_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/net/core/net-traces.c b/net/core/net-traces.c
index 7f1bb2aba03b..13aab64520ad 100644
--- a/net/core/net-traces.c
+++ b/net/core/net-traces.c
@@ -28,6 +28,7 @@
#include <trace/events/skb.h>
#include <trace/events/net.h>
#include <trace/events/napi.h>
+#include <trace/events/udp.h>
EXPORT_TRACEPOINT_SYMBOL_GPL(kfree_skb);
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index abca870d8ff6..37aa9bf8d382 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -105,6 +105,7 @@
#include <net/route.h>
#include <net/checksum.h>
#include <net/xfrm.h>
+#include <trace/events/udp.h>
#include "udp_impl.h"
struct udp_table udp_table __read_mostly;
@@ -1363,6 +1364,7 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
is_udplite);
UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
kfree_skb(skb);
+ trace_udp_fail_queue_rcv_skb(rc, sk);
return -1;
}