Eric Dumazet da882c1f2e tcp: sk_add_backlog() is too agressive for TCP ... While investigating TCP performance problems on 10Gb+ links, we found a tcp sender was dropping lot of incoming ACKS because of sk_rcvbuf limit in sk_add_backlog(), especially if receiver doesnt use GRO/LRO and sends one ACK every two MSS segments. A sender usually tweaks sk_sndbuf, but sk_rcvbuf stays at its default value (87380), allowing a too small backlog. A TCP ACK, even being small, can consume nearly same truesize space than outgoing packets. Using sk_rcvbuf + sk_sndbuf as a limit makes sense and is fast to compute. Performance results on netperf, single flow, receiver with disabled GRO/LRO : 7500 Mbits instead of 6050 Mbits, no more TCPBacklogDrop increments at sender. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2012-04-23 22:28:28 -04:00
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netfilter	net: Convert all sysctl registrations to register_net_sysctl	2012-04-20 21:22:30 -04:00
addrconf_core.c
addrconf.c	net ipv6: Convert addrconf to use register_net_sysctl	2012-04-20 21:22:29 -04:00
addrlabel.c
af_inet6.c	sock: Introduce named constants for sk_reuse	2012-04-21 15:52:25 -04:00
ah6.c
anycast.c
datagram.c
esp6.c
exthdrs_core.c
exthdrs.c
fib6_rules.c
icmp.c
inet6_connection_sock.c
inet6_hashtables.c
ip6_fib.c
ip6_flowlabel.c
ip6_input.c
ip6_output.c
ip6_tunnel.c
ip6mr.c
ipcomp6.c
ipv6_sockglue.c
Kconfig
Makefile
mcast.c
mip6.c
ndisc.c
netfilter.c
proc.c
protocol.c
raw.c
reassembly.c	net: Convert all sysctl registrations to register_net_sysctl	2012-04-20 21:22:30 -04:00
route.c
sit.c
syncookies.c
sysctl_net_ipv6.c	net: Delete all remaining instances of ctl_path	2012-04-20 21:22:30 -04:00
tcp_ipv6.c	tcp: sk_add_backlog() is too agressive for TCP	2012-04-23 22:28:28 -04:00
tunnel6.c
udp_impl.h
udp.c	net: add a limit parameter to sk_add_backlog()	2012-04-23 22:28:28 -04:00
udplite.c
xfrm6_input.c
xfrm6_mode_beet.c
xfrm6_mode_ro.c
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c
xfrm6_output.c
xfrm6_policy.c	net: Convert all sysctl registrations to register_net_sysctl	2012-04-20 21:22:30 -04:00
xfrm6_state.c
xfrm6_tunnel.c