linux-hardened/net/ipv4
Florian Westphal 343dfaa198 Revert "dctcp: update cwnd on congestion event"
Neal Cardwell says:
 If I am reading the code correctly, then I would have two concerns:
 1) Has that been tested? That seems like an extremely dramatic
    decrease in cwnd. For example, if the cwnd is 80, and there are 40
    ACKs, and half the ACKs are ECE marked, then my back-of-the-envelope
    calculations seem to suggest that after just 11 ACKs the cwnd would be
    down to a minimal value of 2 [..]
 2) That seems to contradict another passage in the draft [..] where it
    sazs:
       Just as specified in [RFC3168], DCTCP does not react to congestion
       indications more than once for every window of data.

Neal is right.  Fortunately we don't have to complicate this by testing
vs. current rtt estimate, we can just revert the patch.

Normal stack already handles this for us: receiving ACKs with ECE
set causes a call to tcp_enter_cwr(), from there on the ssthresh gets
adjusted and prr will take care of cwnd adjustment.

Fixes: 4780566784 ("dctcp: update cwnd on congestion event")
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-06 11:34:24 -05:00
..
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
af_inet.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
ah4.c
arp.c net: rename NET_{ADD|INC}_STATS_BH() 2016-04-27 22:48:24 -04:00
cipso_ipv4.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
datagram.c
devinet.c netconf: add a notif when settings are created 2016-09-01 15:18:08 -07:00
esp4.c esp4: Fix integrity verification when ESN are used 2016-11-30 11:09:39 +01:00
fib_frontend.c ipv4: fib: Allow for consistent FIB dumping 2016-12-03 19:29:35 -05:00
fib_lookup.h
fib_rules.c switchdev: remove FIB offload infrastructure 2016-09-28 04:48:00 -04:00
fib_semantics.c ipv4: fib: Export free_fib_info() 2016-12-03 19:29:35 -05:00
fib_trie.c ipv4: fib: Replay events when registering FIB notifier 2016-12-03 19:29:35 -05:00
fou.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
gre_demux.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-06-30 05:03:36 -04:00
gre_offload.c net: add recursion limit to GRO 2016-10-20 14:32:22 -04:00
icmp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-15 10:54:36 -05:00
igmp.c igmp: do not remove igmp souce list info when set link down 2016-11-15 19:51:16 -05:00
inet_connection_sock.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
inet_diag.c tcp: no longer hold ehash lock while calling tcp_get_info() 2016-11-09 13:02:27 -05:00
inet_fragment.c net: disable fragment reassembly if high_thresh is zero 2016-06-05 22:56:42 -04:00
inet_hashtables.c net: Require exact match for TCP socket lookups if dif is l3mdev 2016-10-17 10:17:05 -04:00
inet_timewait_sock.c timers, net/ipv4/inet: Initialize connection request timers as pinned 2016-07-07 10:35:06 +02:00
inetpeer.c
ip_forward.c ipv4: allow local fragmentation in ip_finish_output_gso() 2016-11-03 16:10:26 -04:00
ip_fragment.c net: rename IP_INC_STATS_BH() 2016-04-27 22:48:23 -04:00
ip_gre.c netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
ip_input.c net: VRF: Pass original iif to ip_route_input() 2016-09-16 04:24:07 -04:00
ip_options.c net: ipv4: Convert IP network timestamps to be y2038 safe 2016-03-01 17:18:44 -05:00
ip_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
ip_sockglue.c net/sock: add an explicit sk argument for ip_cmsg_recv_offset() 2016-11-07 13:24:41 -05:00
ip_tunnel.c netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
ip_tunnel_core.c ipv4: allow local fragmentation in ip_finish_output_gso() 2016-11-03 16:10:26 -04:00
ip_vti.c netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
ipcomp.c
ipconfig.c net: ipconfig: Fix NULL pointer dereference on RARP/BOOTP/DHCP timeout 2016-08-22 21:04:41 -07:00
ipip.c netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
ipmr.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-15 10:54:36 -05:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
Makefile net: ip, diag -- Add diag interface for raw sockets 2016-10-23 19:35:24 -04:00
netfilter.c netfilter: Update ip_route_me_harder to consider L3 domain 2016-11-24 12:44:36 +01:00
ping.c net: inet: Support UID-based routing in IP protocols. 2016-11-04 14:45:23 -04:00
proc.c net: Suppress the "Comparison to NULL could be written" warnings 2016-09-30 01:50:45 -04:00
protocol.c
raw.c net: Update raw socket bind to consider l3 domain 2016-11-07 13:14:34 -05:00
raw_diag.c net: ip, raw_diag -- Use jump for exiting from nested loop 2016-11-03 15:25:26 -04:00
route.c route: Set lwtstate for local traffic and cached input dsts 2016-12-02 10:51:49 -05:00
syncookies.c tcp: randomize tcp timestamp offsets for each connection 2016-12-02 12:49:59 -05:00
sysctl_net_ipv4.c ipv4: use the right lock for ping_group_range 2016-10-22 16:23:12 -04:00
tcp.c tcp: tsq: move tsq_flags close to sk_wmem_alloc 2016-12-05 13:32:24 -05:00
tcp_bbr.c tcp_bbr: add a state transition diagram and accompanying comment 2016-10-29 17:12:43 -04:00
tcp_bic.c tcp: replace cnt & rtt with struct in pkts_acked() 2016-05-11 14:43:19 -04:00
tcp_cdg.c tcp: cdg: rename struct minmax in tcp_cdg.c to avoid a naming conflict 2016-09-21 00:22:59 -04:00
tcp_cong.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-22 13:27:16 -05:00
tcp_cubic.c tcp: replace cnt & rtt with struct in pkts_acked() 2016-05-11 14:43:19 -04:00
tcp_dctcp.c Revert "dctcp: update cwnd on congestion event" 2016-12-06 11:34:24 -05:00
tcp_diag.c net: diag: Fix refcnt leak in error path destroying socket 2016-08-23 23:11:36 -07:00
tcp_fastopen.c tcp: fastopen: avoid negative sk_forward_alloc 2016-09-08 16:08:10 -07:00
tcp_highspeed.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_htcp.c tcp: replace cnt & rtt with struct in pkts_acked() 2016-05-11 14:43:19 -04:00
tcp_hybla.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_illinois.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_input.c tcp: allow to turn tcp timestamp randomization off 2016-12-02 12:49:59 -05:00
tcp_ipv4.c tcp: tsq: move tsq_flags close to sk_wmem_alloc 2016-12-05 13:32:24 -05:00
tcp_lp.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_metrics.c genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
tcp_minisocks.c tcp: randomize tcp timestamp offsets for each connection 2016-12-02 12:49:59 -05:00
tcp_nv.c tcp: add NV congestion control 2016-06-10 23:07:49 -07:00
tcp_offload.c gso: Support partial splitting at the frag_list pointer 2016-09-19 20:59:34 -04:00
tcp_output.c tcp: tsq: move tsq_flags close to sk_wmem_alloc 2016-12-05 13:32:24 -05:00
tcp_probe.c net: ipv4: tcp_probe: Replace timespec with timespec64 2016-03-01 17:18:44 -05:00
tcp_rate.c tcp: export data delivery rate 2016-09-21 00:23:00 -04:00
tcp_recovery.c tcp: do not assume TCP code is non preemptible 2016-05-02 17:02:25 -04:00
tcp_scalable.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_timer.c tcp: tsq: move tsq_flags close to sk_wmem_alloc 2016-12-05 13:32:24 -05:00
tcp_vegas.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_vegas.h tcp: replace cnt & rtt with struct in pkts_acked() 2016-05-11 14:43:19 -04:00
tcp_veno.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tcp_westwood.c tcp: make undo_cwnd mandatory for congestion modules 2016-11-21 13:20:17 -05:00
tcp_yeah.c tcp: add cwnd_undo functions to various tcp cc algorithms 2016-11-21 13:20:17 -05:00
tunnel4.c tunnels: correct conditional build of MPLS and IPv6 2016-07-11 13:27:06 -07:00
udp.c udp: be less conservative with sock rmem accounting 2016-12-03 16:14:48 -05:00
udp_diag.c net: inet: diag: expose the socket mark to privileged processes. 2016-09-08 16:13:09 -07:00
udp_impl.h udplite: call proper backlog handlers 2016-11-24 15:32:14 -05:00
udp_offload.c net: add recursion limit to GRO 2016-10-20 14:32:22 -04:00
udp_tunnel.c net: Remove deprecated tunnel specific UDP offload functions 2016-06-17 20:23:32 -07:00
udplite.c udplite: call proper backlog handlers 2016-11-24 15:32:14 -05:00
xfrm4_input.c
xfrm4_mode_beet.c
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c
xfrm4_output.c
xfrm4_policy.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-09-12 15:52:44 -07:00
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c