linux/net/ipv4
Maciej Żenczykowski 79e9fed460 net-tcp: extend tcp_tw_reuse sysctl to enable loopback only optimization
This changes the /proc/sys/net/ipv4/tcp_tw_reuse from a boolean
to an integer.

It now takes the values 0, 1 and 2, where 0 and 1 behave as before,
while 2 enables timewait socket reuse only for sockets that we can
prove are loopback connections:
  ie. bound to 'lo' interface or where one of source or destination
  IPs is 127.0.0.0/8, ::ffff:127.0.0.0/104 or ::1.

This enables quicker reuse of ephemeral ports for loopback connections
- where tcp_tw_reuse is 100% safe from a protocol perspective
(this assumes no artificially induced packet loss on 'lo').

This also makes estblishing many loopback connections *much* faster
(allocating ports out of the first half of the ephemeral port range
is significantly faster, then allocating from the second half)

Without this change in a 32K ephemeral port space my sample program
(it just establishes and closes [::1]:ephemeral -> [::1]:server_port
connections in a tight loop) fails after 32765 connections in 24 seconds.
With it enabled 50000 connections only take 4.7 seconds.

This is particularly problematic for IPv6 where we only have one local
address and cannot play tricks with varying source IP from 127.0.0.0/8
pool.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Wei Wang <weiwan@google.com>
Change-Id: I0377961749979d0301b7b62871a32a4b34b654e1
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-04 17:13:35 -04:00
..
bpfilter net: bpfilter: make function bpfilter_mbox_request() static 2018-05-29 09:51:44 -04:00
netfilter netfilter: Libify xt_TPROXY 2018-06-03 00:02:05 +02:00
af_inet.c tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive 2018-04-29 21:29:55 -04:00
ah4.c net: use -ENOSPC for transient busy indication 2017-11-03 22:11:17 +08:00
arp.c arp: fix arp_filter on l3slave devices 2018-04-05 22:05:03 -04:00
cipso_ipv4.c tcp/dccp: fix ireq->opt races 2017-10-21 01:33:19 +01:00
datagram.c
devinet.c net/ipv4: Add support for specifying metric of connected routes 2018-05-29 10:12:45 -04:00
esp4_offload.c esp: check the NETIF_F_HW_ESP_TX_CSUM bit before segmenting 2018-02-27 10:46:01 +01:00
esp4.c esp4: remove redundant initialization of pointer esph 2018-02-13 13:59:03 +01:00
fib_frontend.c net/ipv4: Add support for specifying metric of connected routes 2018-05-29 10:12:45 -04:00
fib_lookup.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_notifier.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fib_rules.c net: fib_rules: add extack support 2018-04-23 10:21:24 -04:00
fib_semantics.c net: Move fib_convert_metrics to metrics file 2018-04-17 23:41:15 -04:00
fib_trie.c net/ipv4: Udate fib_table_lookup tracepoint 2018-05-24 23:00:31 -04:00
fou.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
gre_demux.c
gre_offload.c gso: fix payload length when gso_size is zero 2017-10-08 10:12:15 -07:00
icmp.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
igmp.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
inet_connection_sock.c net: ipv4: remove define INET_CSK_DEBUG and unnecessary EXPORT_SYMBOL 2018-05-10 17:43:55 -04:00
inet_diag.c sock_diag: request _diag module only when the family or proto has been registered 2018-03-12 11:03:42 -04:00
inet_fragment.c inet: frags: remove inet_frag_maybe_warn_overflow() 2018-03-31 23:25:39 -04:00
inet_hashtables.c inet: Avoid unitialized variable warning in inet_unhash() 2018-02-01 09:48:42 -05:00
inet_timewait_sock.c soreuseport: initialise timewait reuseport field 2018-04-07 22:32:32 -04:00
inetpeer.c inetpeer: fix uninit-value in inet_getpeer 2018-04-09 10:57:35 -04:00
ip_forward.c net: rename skb_gso_validate_mtu -> skb_gso_validate_network_len 2018-03-04 17:49:17 -05:00
ip_fragment.c inet: frags: fix ip6frag_low_thresh boundary 2018-04-04 12:04:59 -04:00
ip_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-21 16:01:54 -04:00
ip_input.c net: Make ip_ra_chain per struct net 2018-03-22 15:12:56 -04:00
ip_options.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-21 16:01:54 -04:00
ip_sockglue.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-26 19:46:15 -04:00
ip_tunnel_core.c net/ipv4: Update ip_tunnel_metadata_cnt static key to modern api 2018-05-10 15:13:33 -04:00
ip_tunnel.c ip_tunnel: restore binding to ifaces with a large mtu 2018-06-01 13:56:29 -04:00
ip_vti.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ipcomp.c
ipconfig.c net: ipv4: ipconfig: fix unused variable 2018-05-13 20:27:25 -04:00
ipip.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
ipmr_base.c ipmr: properly check rhltable_init() return value 2018-05-22 15:31:15 -04:00
ipmr.c net: fib_rules: add extack support 2018-04-23 10:21:24 -04:00
Kconfig ipmr,ipmr6: Define a uniform vif_device 2018-03-01 13:13:23 -05:00
Makefile ipv4: support sport, dport and ip_proto in RTM_GETROUTE 2018-05-23 15:14:12 -04:00
metrics.c net: Move fib_convert_metrics to metrics file 2018-04-17 23:41:15 -04:00
netfilter.c netfilter: remove struct nf_afinfo and its helper functions 2018-01-08 18:11:02 +01:00
netlink.c ipv4: support sport, dport and ip_proto in RTM_GETROUTE 2018-05-23 15:14:12 -04:00
ping.c ipv4: fix memory leaks in udp_sendmsg, ping_v4_sendmsg 2018-05-11 12:00:58 -04:00
proc.c tcp: add TCPAckCompressed SNMP counter 2018-05-18 11:40:27 -04:00
protocol.c
raw_diag.c net: ipv6: add second dif to raw socket lookups 2017-08-07 11:39:22 -07:00
raw.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-05-24 22:20:51 -04:00
syncookies.c net/ipv4: disable SMC TCP option with SYN Cookies 2018-03-25 20:53:54 -04:00
sysctl_net_ipv4.c net-tcp: extend tcp_tw_reuse sysctl to enable loopback only optimization 2018-06-04 17:13:35 -04:00
tcp_bbr.c tcp_bbr: fix to zero idle_restart only upon S/ACKed data 2018-05-02 11:12:32 -04:00
tcp_bic.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_cdg.c tcp: cdg: make struct tcp_cdg static 2017-10-16 21:24:25 +01:00
tcp_cong.c tcp: Namespace-ify sysctl_tcp_default_congestion_control 2017-11-15 14:09:52 +09:00
tcp_cubic.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_dctcp.c
tcp_diag.c net: sock: replace sk_state_load with inet_sk_state_load and remove sk_state_store 2017-12-20 14:00:25 -05:00
tcp_fastopen.c tcp: pause Fast Open globally after third consecutive timeout 2017-12-13 15:51:12 -05:00
tcp_highspeed.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_htcp.c tcp: fix cwnd undo in Reno and HTCP congestion controls 2017-08-06 21:25:10 -07:00
tcp_hybla.c
tcp_illinois.c net/tcp/illinois: replace broken algorithm reference link 2018-02-28 12:03:47 -05:00
tcp_input.c tcp: minor optimization around tcp_hdr() usage in receive path 2018-05-31 13:20:47 -04:00
tcp_ipv4.c net-tcp: extend tcp_tw_reuse sysctl to enable loopback only optimization 2018-06-04 17:13:35 -04:00
tcp_lp.c tcp: switch TCP TS option (RFC 7323) to 1ms clock 2017-05-17 16:06:01 -04:00
tcp_metrics.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
tcp_minisocks.c tcp: Add mark for TIMEWAIT sockets 2018-05-10 17:44:52 -04:00
tcp_nv.c tcp_nv: fix potential integer overflow in tcpnv_acked 2018-01-31 10:26:30 -05:00
tcp_offload.c gso: validate gso_type in GSO handlers 2018-01-22 16:01:30 -05:00
tcp_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-05-21 16:01:54 -04:00
tcp_rate.c tcp: invalidate rate samples during SACK reneging 2017-12-08 10:07:02 -05:00
tcp_recovery.c tcp: tcp_rack_reo_wnd() can be static 2018-05-18 13:28:40 -04:00
tcp_scalable.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_timer.c tcp: add SACK compression 2018-05-18 11:40:27 -04:00
tcp_ulp.c net: add a UID to use for ULP socket assignment 2018-02-06 11:39:31 +01:00
tcp_vegas.c tcp: fix under-evaluated ssthresh in TCP Vegas 2017-09-29 06:07:00 +01:00
tcp_vegas.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tcp_veno.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp_westwood.c tcp: Revert "tcp: remove CA_ACK_SLOWPATH" 2017-08-30 11:20:08 -07:00
tcp_yeah.c tcp: consolidate congestion control undo functions 2017-08-06 21:25:10 -07:00
tcp.c tcp: add SACK compression 2018-05-18 11:40:27 -04:00
tunnel4.c inet: whitespace cleanup 2018-02-28 11:43:28 -05:00
udp_diag.c net: ipv6: add second dif to udp socket lookups 2017-08-07 11:39:22 -07:00
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c udp: avoid refcount_t saturation in __udp_gso_segment() 2018-05-11 12:29:42 -04:00
udp_tunnel.c net: add infrastructure to un-offload UDP tunnel port 2017-07-24 13:52:59 -07:00
udp.c udp: exclude gso from xfrm paths 2018-05-23 14:48:44 -04:00
udplite.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
xfrm4_input.c xfrm: Reinject transport-mode packets through tasklet 2017-12-19 08:23:21 +01:00
xfrm4_mode_beet.c networking: make skb_pull & friends return void pointers 2017-06-16 11:48:39 -04:00
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto 2018-03-07 10:54:29 +01:00
xfrm4_output.c net: xfrm: use skb_gso_validate_network_len() to check gso sizes 2018-03-04 17:49:17 -05:00
xfrm4_policy.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
xfrm4_protocol.c
xfrm4_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm4_tunnel.c