From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 25 Jan 2012 04:44:20 +0000 (+0000)
Subject: tcp: add LINUX_MIB_TCPRETRANSFAIL counter
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=09e9b813d34d9a09d64a64580a9959d8bae1f4f5;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

tcp: add LINUX_MIB_TCPRETRANSFAIL counter

It might be useful to get a counter of failed tcp_retransmit_skb()
calls.

Reported-by: Satoru Moriya <satoru.moriya@hds.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/linux/snmp.h b/include/linux/snmp.h
index c1241c428179..8ee8af4e6da9 100644
--- a/include/linux/snmp.h
+++ b/include/linux/snmp.h
@@ -232,6 +232,7 @@ enum
 	LINUX_MIB_TCPTIMEWAITOVERFLOW,		/* TCPTimeWaitOverflow */
 	LINUX_MIB_TCPREQQFULLDOCOOKIES,		/* TCPReqQFullDoCookies */
 	LINUX_MIB_TCPREQQFULLDROP,		/* TCPReqQFullDrop */
+	LINUX_MIB_TCPRETRANSFAIL,		/* TCPRetransFail */
 	__LINUX_MIB_MAX
 };
 
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 6afc807ee2ad..02d61079f08b 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -256,6 +256,7 @@ static const struct snmp_mib snmp4_net_list[] = {
 	SNMP_MIB_ITEM("TCPTimeWaitOverflow", LINUX_MIB_TCPTIMEWAITOVERFLOW),
 	SNMP_MIB_ITEM("TCPReqQFullDoCookies", LINUX_MIB_TCPREQQFULLDOCOOKIES),
 	SNMP_MIB_ITEM("TCPReqQFullDrop", LINUX_MIB_TCPREQQFULLDROP),
+	SNMP_MIB_ITEM("TCPRetransFail", LINUX_MIB_TCPRETRANSFAIL),
 	SNMP_MIB_SENTINEL
 };
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8c8de2780c7a..561550ab3c30 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2308,8 +2308,10 @@ begin_fwd:
 		if (sacked & (TCPCB_SACKED_ACKED|TCPCB_SACKED_RETRANS))
 			continue;
 
-		if (tcp_retransmit_skb(sk, skb))
+		if (tcp_retransmit_skb(sk, skb)) {
+			NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRETRANSFAIL);
 			return;
+		}
 		NET_INC_STATS_BH(sock_net(sk), mib_idx);
 
 		if (inet_csk(sk)->icsk_ca_state == TCP_CA_Recovery)