linux/net/ipv4
Eric Dumazet 0e280af026 tcp: introduce TCPSpuriousRtxHostQueues SNMP counter
Host queues (Qdisc + NIC) can hold packets so long that TCP can
eventually retransmit a packet before the first transmit even left
the host.

Its not clear right now if we could avoid this in the first place :

- We could arm RTO timer not at the time we enqueue packets, but
  at the time we TX complete them (tcp_wfree())

- Cancel the sending of the new copy of the packet if prior one
  is still in queue.

This patch adds instrumentation so that we can at least see how
often this problem happens.

TCPSpuriousRtxHostQueues SNMP counter is incremented every time
we detect the fast clone is not yet freed in tcp_transmit_skb()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-18 14:57:25 -04:00
..
netfilter Merge branch 'master' of git://1984.lsi.us.es/nf-next 2013-04-07 12:22:06 -04:00
af_inet.c ipv4: Fix ip-header identification for gso packets. 2013-03-26 13:50:05 -04:00
ah4.c net: Add skb_unclone() helper function. 2013-02-15 15:10:37 -05:00
arp.c firewire net, ipv4 arp: Extend hardware address and remove driver-level packet inspection. 2013-03-26 12:32:13 -04:00
cipso_ipv4.c cipso: don't follow a NULL pointer when setsockopt() is called 2012-07-18 09:01:12 -07:00
datagram.c ipv4: Add a socket release callback for datagram sockets 2013-01-21 14:17:05 -05:00
devinet.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-04-07 18:37:01 -04:00
esp4.c xfrm4: Invalidate all ipv4 routes on IPsec pmtu events 2013-01-21 12:43:54 +01:00
fib_frontend.c net-next: replace obsolete NLMSG_* with type safe nlmsg_* 2013-03-28 14:25:25 -04:00
fib_lookup.h ipv4: Fix nexthop caching wrt. scoping. 2011-03-24 18:06:47 -07:00
fib_rules.c sections: fix section conflicts in net 2012-10-06 03:04:45 +09:00
fib_semantics.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
fib_trie.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
gre.c GRE: Refactor GRE tunneling code. 2013-03-26 12:27:18 -04:00
icmp.c ipv4: fix error handling in icmp_protocol. 2013-02-22 15:10:18 -05:00
igmp.c net: proc: change proc_net_remove to remove_proc_entry 2013-02-18 14:53:08 -05:00
inet_connection_sock.c tcp: Remove TCPCT 2013-03-17 14:35:13 -04:00
inet_diag.c tcp: Tail loss probe (TLP) 2013-03-12 08:30:34 -04:00
inet_fragment.c net: frag queue per hash bucket locking 2013-04-04 17:37:05 -04:00
inet_hashtables.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
inet_lro.c ipv4: replace ip_fast_csum with csum_replace2 2013-03-15 09:12:25 -04:00
inet_timewait_sock.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
inetpeer.c Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2012-10-02 09:54:49 -07:00
ip_forward.c ipv4: introduce rt_uses_gateway 2012-10-08 17:42:36 -04:00
ip_fragment.c inet: generalize ipv4-only RFC3168 5.3 ecn fragmentation handling for future use by ipv6 2013-03-24 17:16:30 -04:00
ip_gre.c ip_gre: fix a possible crash in parse_gre_header() 2013-04-08 12:00:17 -04:00
ip_input.c ipv[4|6]: correct dropwatch false positive in local_deliver_finish 2013-03-01 15:56:29 -05:00
ip_options.c net/ipv4: Ensure that location of timestamp option is stored 2013-03-12 05:35:39 -04:00
ip_output.c netfilter: use IS_ENABLE to replace if defined in TRACE target 2013-04-02 01:03:45 +02:00
ip_sockglue.c net: prevent setting ttl=0 via IP_TTL 2013-01-08 17:57:10 -08:00
ip_tunnel.c ip_tunnel: Fix off-by-one error in forming dev name. 2013-03-29 15:24:28 -04:00
ip_vti.c Tunneling: use IP Tunnel stats APIs. 2013-03-26 12:27:19 -04:00
ipcomp.c xfrm: allow to avoid copying DSCP during encapsulation 2013-03-06 07:02:45 +01:00
ipconfig.c ipconfig: add informative timeout messages while waiting for carrier 2013-04-02 14:35:33 -04:00
ipip.c IPIP: Use ip-tunneling code. 2013-03-26 12:27:18 -04:00
ipmr.c net-next: replace obsolete NLMSG_* with type safe nlmsg_* 2013-03-28 14:25:25 -04:00
Kconfig Tunneling: use IP Tunnel stats APIs. 2013-03-26 12:27:19 -04:00
Makefile GRE: Refactor GRE tunneling code. 2013-03-26 12:27:18 -04:00
netfilter.c netfilter: properly annotate ipv4_netfilter_{init,fini}() 2012-09-03 13:56:04 +02:00
ping.c net: sock: make sock_tx_timestamp void 2013-04-14 15:41:49 -04:00
proc.c tcp: introduce TCPSpuriousRtxHostQueues SNMP counter 2013-04-18 14:57:25 -04:00
protocol.c ipv4: Disallow non-namespace aware protocols to register. 2013-02-05 14:42:23 -05:00
raw.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
route.c rtnetlink: Remove passing of attributes into rtnl_doit functions 2013-03-22 10:31:16 -04:00
syncookies.c tcp: Remove TCPCT 2013-03-17 14:35:13 -04:00
sysctl_net_ipv4.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_bic.c tcp: fix undo after RTO for BIC 2012-01-20 14:17:26 -05:00
tcp_cong.c tcp: remove Appropriate Byte Count support 2013-02-05 14:51:16 -05:00
tcp_cubic.c tcp: fix undo after RTO for CUBIC 2012-01-20 14:17:26 -05:00
tcp_diag.c inet_diag: Rename inet_diag_req into inet_diag_req_v2 2012-01-11 12:56:06 -08:00
tcp_fastopen.c tcp: TCP Fast Open Server - header & support functions 2012-08-31 20:02:18 -04:00
tcp_highspeed.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_htcp.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_hybla.c tcp: bool conversions 2012-05-17 14:59:59 -04:00
tcp_illinois.c net: fix divide by zero in tcp algorithm illinois 2012-11-01 11:55:59 -04:00
tcp_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-03-27 13:52:49 -04:00
tcp_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-03-20 12:46:26 -04:00
tcp_lp.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp_memcontrol.c net: tcp_memcontrol: minor: remove unused variable 2013-04-14 15:41:49 -04:00
tcp_metrics.c tcp: handle tcp_net_metrics_init() order-5 memory allocation failures 2012-11-16 13:36:27 -05:00
tcp_minisocks.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_output.c tcp: introduce TCPSpuriousRtxHostQueues SNMP counter 2013-04-18 14:57:25 -04:00
tcp_probe.c net: proc: change proc_net_remove to remove_proc_entry 2013-02-18 14:53:08 -05:00
tcp_scalable.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_timer.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_vegas.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_vegas.h
tcp_veno.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_westwood.c tcp: refactor F-RTO 2013-03-21 11:47:50 -04:00
tcp_yeah.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp.c tcp: tcp_tso_segment() small optimization 2013-04-13 16:54:14 -04:00
tunnel4.c net: Convert printks to pr_<level> 2012-03-11 23:42:51 -07:00
udp_diag.c net-next: replace obsolete NLMSG_* with type safe nlmsg_* 2013-03-28 14:25:25 -04:00
udp_impl.h ipv4: fix checkpatch errors 2012-04-15 12:37:19 -04:00
udp.c net: sock: make sock_tx_timestamp void 2013-04-14 15:41:49 -04:00
udplite.c net: ipv4: Standardize prefixes for message logging 2012-03-12 17:05:21 -07:00
xfrm4_input.c net: Add skb_unclone() helper function. 2013-02-15 15:10:37 -05:00
xfrm4_mode_beet.c ipsec: be careful of non existing mac headers 2012-02-23 16:50:45 -05:00
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c xfrm: allow to avoid copying DSCP during encapsulation 2013-03-06 07:02:45 +01:00
xfrm4_output.c xfrm4: Don't call icmp_send on local error 2011-07-01 17:33:19 -07:00
xfrm4_policy.c xfrm: make gc_thresh configurable in all namespaces 2013-02-06 11:36:29 +01:00
xfrm4_state.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
xfrm4_tunnel.c net: ipv4: Standardize prefixes for message logging 2012-03-12 17:05:21 -07:00