linux/net
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
..
9p virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf 2012-01-12 15:44:42 +10:30
802 net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
8021q vlan: static functions 2011-12-14 02:39:30 -05:00
appletalk net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
atm net: Rename dst_get_neighbour{, _raw} to dst_get_neighbour_noref{, _raw}. 2011-12-05 15:20:19 -05:00
ax25 ax25: avoid overflows in ax25_setsockopt() 2011-12-28 14:08:08 -05:00
batman-adv batman-adv: Fix merge error. 2011-12-16 15:07:28 -05:00
bluetooth Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/padovan/bluetooth-next 2012-01-10 15:44:17 -05:00
bridge bridge: BH already disabled in br_fdb_cleanup() 2012-01-17 10:17:32 -05:00
caif caif: Remove bad WARN_ON in caif_dev 2012-01-17 10:46:55 -05:00
can can: remove references to berlios mailinglist 2011-10-17 19:22:46 -04:00
ceph libceph: remove useless return value for osd_client __send_request() 2012-01-10 08:57:03 -08:00
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-01-17 22:26:41 -08:00
dcb net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
dccp inet_diag: Rename inet_diag_req into inet_diag_req_v2 2012-01-11 12:56:06 -08:00
decnet Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security 2012-01-14 18:36:33 -08:00
dns_resolver
dsa dsa: Move switch drivers to new directory drivers/net/dsa 2011-11-29 00:21:36 -05:00
econet net: Remove all uses of LL_ALLOCATED_SPACE 2011-11-18 14:37:09 -05:00
ethernet
ieee802154 net: Remove all uses of LL_ALLOCATED_SPACE 2011-11-18 14:37:09 -05:00
ipv4 tcp: fix undo after RTO for CUBIC 2012-01-20 14:17:26 -05:00
ipv6 net: race condition in ipv6 forwarding and disable_ipv6 parameters 2012-01-18 16:38:34 -05:00
ipx net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
irda irda: use msecs_to_jiffies() rather than manual calculation 2011-12-21 15:46:22 -05:00
iucv af_iucv: get rid of state IUCV_SEVERED 2011-12-20 14:05:03 -05:00
key net: use IS_ENABLED(CONFIG_IPV6) 2011-12-11 18:25:16 -05:00
l2tp l2tp: ensure sk->dst is still valid 2011-11-26 15:57:36 -05:00
lapb
llc llc: llc_cmsg_rcv was getting called after sk_eat_skb. 2011-12-19 15:58:52 -05:00
mac80211 mac80211: fix work removal on deauth request 2012-01-18 14:38:06 -05:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-01-17 22:26:41 -08:00
netlabel net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
netlink Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security 2012-01-14 18:36:33 -08:00
netrom netrom: avoid overflows in nr_setsockopt() 2011-12-28 14:08:08 -05:00
nfc NFC: Export a new attribute nfcid1 in target info 2012-01-04 14:30:43 -05:00
openvswitch openvswitch: Fix multipart datapath dumps. 2012-01-17 23:56:19 -05:00
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2011-12-30 13:04:14 -05:00
phonet net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
rds RDS: Remove some unused iWARP code 2012-01-12 20:05:28 -08:00
rfkill Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2012-01-05 10:13:24 -05:00
rose net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
rxrpc net: fix assignment of 0/1 to bool variables. 2011-12-19 22:27:29 -05:00
sched net_sched: sfq: add optional RED on top of SFQ 2012-01-12 20:05:28 -08:00
sctp Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-01-08 13:21:22 -08:00
sunrpc Merge branch 'for-3.3' of git://linux-nfs.org/~bfields/linux 2012-01-14 12:26:41 -08:00
tipc tipc: rename struct bearer_name to struct tipc_bearer_names 2011-12-29 21:53:30 -05:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-01-09 14:46:52 -08:00
wanrouter wanrouter: Remove kernel_lock annotations 2011-11-07 13:27:30 -05:00
wimax net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
wireless nl80211: fix old station flags compatibility 2012-01-11 15:14:50 -05:00
x25 net:x25: use IS_ENABLED 2011-12-16 15:49:52 -05:00
xfrm Merge branch 'for-linus' of git://selinuxproject.org/~jmorris/linux-security 2012-01-14 18:36:33 -08:00
compat.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
Kconfig net: Add Open vSwitch kernel components. 2011-12-03 09:35:17 -08:00
Makefile net: Add Open vSwitch kernel components. 2011-12-03 09:35:17 -08:00
nonet.c
socket.c net: reintroduce missing rcu_assign_pointer() calls 2012-01-12 12:26:56 -08:00
sysctl_net.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00