linux/net/ipv4
Neal Cardwell 5a45f0086a tcp: fix undo after RTO for CUBIC
This patch fixes CUBIC so that cwnd reductions made during RTOs can be
undone (just as they already can be undone when using the default/Reno
behavior).

When undoing cwnd reductions, BIC-derived congestion control modules
were restoring the cwnd from last_max_cwnd. There were two problems
with using last_max_cwnd to restore a cwnd during undo:

(a) last_max_cwnd was set to 0 on state transitions into TCP_CA_Loss
(by calling the module's reset() functions), so cwnd reductions from
RTOs could not be undone.

(b) when fast_covergence is enabled (which it is by default)
last_max_cwnd does not actually hold the value of snd_cwnd before the
loss; instead, it holds a scaled-down version of snd_cwnd.

This patch makes the following changes:

(1) upon undo, revert snd_cwnd to ca->loss_cwnd, which is already, as
the existing comment notes, the "congestion window at last loss"

(2) stop forgetting ca->loss_cwnd on TCP_CA_Loss events

(3) use ca->last_max_cwnd to check if we're in slow start

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Sangtae Ha <sangtae.ha@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-20 14:17:26 -05:00
..
netfilter Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security 2012-01-14 18:36:33 -08:00
af_inet.c per-netns ipv4 sysctl_tcp_mem 2011-12-12 19:04:11 -05:00
ah4.c ah: Don't return NET_XMIT_DROP on input. 2011-11-12 18:13:32 -05:00
arp.c ipv6: Use universal hash for NDISC. 2011-12-28 15:06:58 -05:00
cipso_ipv4.c cipso: remove an unneeded NULL check in cipso_v4_doi_add() 2011-10-11 18:43:53 -04:00
datagram.c ipv4: Lock socket and use cork flow in ip4_datagram_connect(). 2011-05-08 13:48:57 -07:00
devinet.c net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
esp4.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
fib_frontend.c rtnetlink: Compute and store minimum ifinfo dump size 2011-06-09 20:38:07 -07:00
fib_lookup.h ipv4: Fix nexthop caching wrt. scoping. 2011-03-24 18:06:47 -07:00
fib_rules.c net: ipv4: export fib_lookup and fib_table_lookup 2011-12-04 22:43:33 +01:00
fib_semantics.c ipv4: Fix fib_info->fib_metrics leak 2011-09-16 17:42:26 -04:00
fib_trie.c net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
gre.c rcu: convert uses of rcu_assign_pointer(x, NULL) to RCU_INIT_POINTER 2011-08-02 04:29:23 -07:00
icmp.c net: more accurate skb truesize 2011-10-13 16:05:07 -04:00
igmp.c net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
inet_connection_sock.c net: use IS_ENABLED(CONFIG_IPV6) 2011-12-11 18:25:16 -05:00
inet_diag.c inet_diag: Rename inet_diag_req_compat into inet_diag_req 2012-01-11 12:56:06 -08:00
inet_fragment.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
inet_hashtables.c net: Compute protocol sequence numbers and fragment IDs using MD5. 2011-08-06 18:33:19 -07:00
inet_lro.c net: add skb frag size accessors 2011-10-19 03:10:46 -04:00
inet_timewait_sock.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
inetpeer.c inetpeer: initialize ->redirect_genid in inet_getpeer() 2012-01-17 15:52:12 -05:00
ip_forward.c ipv4: Save nexthop address of LSRR/SSRR option to IPCB. 2011-11-23 19:19:32 -05:00
ip_fragment.c treewide: Fix typos in various parts of the kernel, and fix some comments. 2011-12-02 14:57:31 +01:00
ip_gre.c net: use IS_ENABLED(CONFIG_IPV6) 2011-12-11 18:25:16 -05:00
ip_input.c ip: introduce ip_is_fragment helper inline function 2011-06-21 20:33:34 -07:00
ip_options.c ipv4: Save nexthop address of LSRR/SSRR option to IPCB. 2011-11-23 19:19:32 -05:00
ip_output.c net: Rename dst_get_neighbour{, _raw} to dst_get_neighbour_noref{, _raw}. 2011-12-05 15:20:19 -05:00
ip_sockglue.c net: use IS_ENABLED(CONFIG_IPV6) 2011-12-11 18:25:16 -05:00
ipcomp.c inet: constify ip headers and in6_addr 2011-04-22 11:04:14 -07:00
ipconfig.c net: fix some sparse errors 2012-01-17 10:31:12 -05:00
ipip.c net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
ipmr.c net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-01-09 14:46:52 -08:00
Makefile tcp memory pressure controls 2011-12-12 19:04:10 -05:00
netfilter.c netfilter: possible unaligned packet header in ip_route_me_harder 2011-11-21 18:46:18 +01:00
ping.c net: fix some sparse errors 2012-01-17 10:31:12 -05:00
proc.c foundations of per-cgroup memory pressure controlling. 2011-12-12 19:04:10 -05:00
protocol.c net: add __rcu annotations to protocol 2010-10-27 11:37:31 -07:00
raw.c ipv4: Remove all uses of LL_ALLOCATED_SPACE 2011-11-18 14:37:08 -05:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2011-12-23 17:13:56 -05:00
syncookies.c tcp: Replace constants with #define macros 2011-12-21 01:03:23 -05:00
sysctl_net_ipv4.c net: ping: remove some sparse errors 2011-12-14 13:34:55 -05:00
tcp_bic.c tcp: fix undo after RTO for BIC 2012-01-20 14:17:26 -05:00
tcp_cong.c tcp: do not scale TSO segment size with reordering degree 2011-11-29 00:29:41 -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_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: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_illinois.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_input.c tcp: Replace constants with #define macros 2011-12-21 01:03:23 -05:00
tcp_ipv4.c per-netns ipv4 sysctl_tcp_mem 2011-12-12 19:04:11 -05:00
tcp_lp.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp_memcontrol.c net: decrement memcg jump label when limit, not usage, is changed 2012-01-12 12:27:59 -08:00
tcp_minisocks.c net: use IS_ENABLED(CONFIG_IPV6) 2011-12-11 18:25:16 -05:00
tcp_output.c foundations of per-cgroup memory pressure controlling. 2011-12-12 19:04:10 -05:00
tcp_probe.c net: ipv4: tcp_probe: cleanup snprintf() use 2010-11-17 12:27:46 -08:00
tcp_scalable.c tcp: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_timer.c net: fix assignment of 0/1 to bool variables. 2011-12-19 22:27:29 -05:00
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: mark tcp_congestion_ops read_mostly 2011-03-10 00:40:17 -08:00
tcp_yeah.c Fix common misspellings 2011-03-31 11:26:23 -03:00
tcp.c per-netns ipv4 sysctl_tcp_mem 2011-12-12 19:04:11 -05:00
tunnel4.c net: use IS_ENABLED(CONFIG_IPV6) 2011-12-11 18:25:16 -05:00
udp_diag.c net: kill duplicate included header 2012-01-17 10:31:12 -05:00
udp_impl.h net: Make setsockopt() optlen be unsigned. 2009-09-30 16:12:20 -07:00
udp.c udp: Export code sk lookup routines 2011-12-09 14:14:08 -05:00
udplite.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
xfrm4_input.c net/ipv4: EXPORT_SYMBOL cleanups 2010-07-12 12:57:54 -07:00
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c ipv4: Don't pre-seed hoplimit metric. 2010-12-12 22:08:17 -08:00
xfrm4_output.c xfrm4: Don't call icmp_send on local error 2011-07-01 17:33:19 -07:00
xfrm4_policy.c ipv4: fix ipsec forward performance regression 2011-10-24 03:01:22 -04:00
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: use IS_ENABLED(CONFIG_IPV6) 2011-12-11 18:25:16 -05:00