linux/net
Yuchung Cheng 989e04c5bc tcp: improve undo on timeout
Upon timeout, undo (via both timestamps/Eifel and DSACKs) was
disabled if any retransmits were still in flight.  The concern was
perhaps that spurious retransmission sent in a previous recovery
episode may trigger DSACKs to falsely undo the current recovery.

However, this inadvertently misses undo opportunities (using either
TCP timestamps or DSACKs) when timeout occurs during a loss episode,
i.e.  recurring timeouts or timeout during fast recovery. In these
cases some retransmissions will be in flight but we should allow
undo. Furthermore, we should only reset undo_marker and undo_retrans
upon timeout if we are starting a new recovery episode. Finally,
when we do reset our undo state, we now do so in a manner similar
to tcp_enter_recovery(), so that we require a DSACK for each of
the outstsanding retransmissions. This will achieve the original
goal by requiring that we receive the same number of DSACKs as
retransmissions.

This patch increases the undo events by 50% on Google servers.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22 21:28:02 -07:00
..
6lowpan 6lowpan: Allow 6LoWPAN to be modular 2014-08-07 11:44:18 -07:00
9p 9P: remove unnecessary break after return 2014-07-15 16:27:00 -07:00
802 net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
8021q net: Always untag vlan-tagged traffic on input. 2014-08-11 12:16:51 -07:00
appletalk Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-07-16 14:09:34 -07:00
atm lec: Fix bug introduced by b67bfe0d42 2014-08-13 20:04:46 -07:00
ax25 net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
batman-adv batman: fix duplicate #include of multicast.h 2014-08-07 16:02:57 -07:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-08-06 09:38:14 -07:00
bridge br_multicast: Replace rcu_assign_pointer() with RCU_INIT_POINTER() 2014-08-22 12:23:11 -07:00
caif caif: remove unnecessary break after goto 2014-07-15 16:27:01 -07:00
can can: add hash based access to single EFF frame filters 2014-05-19 09:38:24 +02:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2014-08-13 17:43:29 -06:00
core net: remove dead code after sk_data_ready change 2014-08-22 21:08:50 -07:00
dcb dcbnl : Fix misleading dcb_app->priority explanation 2014-07-30 17:21:05 -07:00
dccp inet: move ipv6only in sock_common 2014-07-01 23:46:21 -07:00
decnet af_decnet: Use time_after_eq 2014-08-22 12:23:11 -07:00
dns_resolver Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2014-08-06 08:06:39 -07:00
dsa net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
ethernet net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
hsr net/hsr: Remove left-over never-true conditional code. 2014-07-11 15:04:40 -07:00
ieee802154 inet: frags: use kmem_cache for inet_frag_queue 2014-08-02 15:31:31 -07:00
ipv4 tcp: improve undo on timeout 2014-08-22 21:28:02 -07:00
ipv6 tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced() 2014-08-14 14:38:54 -07:00
ipx net: Split sk_no_check into sk_no_check_{rx,tx} 2014-05-23 16:28:53 -04:00
irda irda: Fix rd_frame control field initialization in irlap_send_rd_frame() 2014-08-13 20:05:52 -07:00
iucv af_iucv: avoid path quiesce of severed path in shutdown() 2014-07-21 20:21:40 -07:00
key af_key: remove unnecessary break after return 2014-07-15 16:27:00 -07:00
l2tp net: use inet6_iif instead of IP6CB()->iif 2014-07-31 22:37:06 -07:00
lapb
llc
mac80211 Merge tag 'master-2014-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next 2014-07-28 17:36:25 -07:00
mac802154 net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
mpls gre: Call gso_make_checksum 2014-06-04 22:46:38 -07:00
netfilter net: use ktime_get_ns() and ktime_get_real_ns() helpers 2014-08-22 19:57:23 -07:00
netlabel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-08-06 09:38:14 -07:00
netlink netlink: Annotate RCU locking for seq_file walker 2014-08-14 15:13:40 -07:00
netrom net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
nfc Merge tag 'master-2014-07-31' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next 2014-08-05 13:18:20 -07:00
openvswitch net/openvswitch/flow.c: Replace rcu_dereference() with rcu_access_pointer() 2014-08-22 12:23:10 -07:00
packet packet: remove deprecated syststamp timestamp 2014-07-29 11:39:50 -07:00
phonet net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-06-12 14:27:40 -07:00
rfkill Merge git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next 2014-05-22 13:58:36 -04:00
rose net: set name_assign_type in alloc_netdev() 2014-07-15 16:12:48 -07:00
rxrpc net: remove dead code after sk_data_ready change 2014-08-22 21:08:50 -07:00
sched net: use ktime_get_ns() and ktime_get_real_ns() helpers 2014-08-22 19:57:23 -07:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-08-05 18:46:26 -07:00
sunrpc NFS client updates for Linux 3.17 2014-08-13 18:13:19 -06:00
tipc tipc: remove duplicated include from socket.c 2014-07-29 15:51:14 -07:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-06-12 14:27:40 -07:00
vmw_vsock vsock: Make transport the proto owner 2014-05-05 13:13:50 -04:00
wimax
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2014-07-25 10:22:36 -04:00
x25 net: Fix use after free by removing length arg from sk_data_ready callbacks. 2014-04-11 16:15:36 -04:00
xfrm list: fix order of arguments for hlist_add_after(_rcu) 2014-08-06 18:01:24 -07:00
compat.c net: sendmsg: fix NULL pointer dereference 2014-07-29 12:20:22 -07:00
Kconfig 6lowpan: introduce new net/6lowpan directory 2014-07-12 01:53:30 +02:00
Makefile 6lowpan: introduce new net/6lowpan directory 2014-07-12 01:53:30 +02:00
nonet.c
socket.c net-timestamp: sock_tx_timestamp() fix 2014-08-06 12:38:07 -07:00
sysctl_net.c