linux_dsm_epyc7002/net/ipv4
Eric Dumazet 662051215c tcp: grow window for OOO packets only for SACK flows
Back in 2013, we made a change that broke fast retransmit
for non SACK flows.

Indeed, for these flows, a sender needs to receive three duplicate
ACK before starting fast retransmit. Sending ACK with different
receive window do not count.

Even if enabling SACK is strongly recommended these days,
there still are some cases where it has to be disabled.

Not increasing the window seems better than having to
rely on RTO.

After the fix, following packetdrill test gives :

// Initialize connection
    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
   +0 bind(3, ..., ...) = 0
   +0 listen(3, 1) = 0

   +0 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7>
   +0 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 8>
   +0 < . 1:1(0) ack 1 win 514

   +0 accept(3, ..., ...) = 4

   +0 < . 1:1001(1000) ack 1 win 514
// Quick ack
   +0 > . 1:1(0) ack 1001 win 264

   +0 < . 2001:3001(1000) ack 1 win 514
// DUPACK : Normally we should not change the window
   +0 > . 1:1(0) ack 1001 win 264

   +0 < . 3001:4001(1000) ack 1 win 514
// DUPACK : Normally we should not change the window
   +0 > . 1:1(0) ack 1001 win 264

   +0 < . 4001:5001(1000) ack 1 win 514
// DUPACK : Normally we should not change the window
    +0 > . 1:1(0) ack 1001 win 264

   +0 < . 1001:2001(1000) ack 1 win 514
// Hole is repaired.
   +0 > . 1:1(0) ack 5001 win 272

Fixes: 4e4f1fc226 ("tcp: properly increase rcv_ssthresh for ofo packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-16 13:38:19 -07:00
..
bpfilter
netfilter treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
af_inet.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-05-22 18:30:34 -07:00
ah4.c
arp.c
bpf_tcp_ca.c
cipso_ipv4.c netlabel: cope with NULL catmap 2020-05-12 18:12:40 -07:00
datagram.c
devinet.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
esp4_offload.c esp4: improve xfrm4_beet_gso_segment() to be more readable 2020-05-18 09:55:19 +02:00
esp4.c
fib_frontend.c ipv4: nexthop version of fib_info_nh_uses_dev 2020-05-26 16:06:07 -07:00
fib_lookup.h
fib_notifier.c
fib_rules.c
fib_semantics.c net: ipv4: add sysctl for nexthop api compatibility mode 2020-04-28 12:50:37 -07:00
fib_trie.c ipv4: Refactor nhc evaluation in fib_table_lookup 2020-05-26 16:06:07 -07:00
fou.c
gre_demux.c
gre_offload.c
icmp.c docs: networking: convert ip-sysctl.txt to ReST 2020-04-28 14:40:18 -07:00
igmp.c ip*_mc_gsfget(): lift copyout of struct group_filter into callers 2020-05-20 20:31:27 -04:00
inet_connection_sock.c inet_connection_sock: clear inet_num out of destroy helper 2020-06-04 15:59:56 -07:00
inet_diag.c inet_diag: bc: read cgroup id only for full sockets 2020-05-02 16:42:51 -07:00
inet_fragment.c
inet_hashtables.c
inet_timewait_sock.c
inetpeer.c
ip_forward.c
ip_fragment.c
ip_gre.c net: add a new ndo_tunnel_ioctl method 2020-05-19 15:45:11 -07:00
ip_input.c
ip_options.c
ip_output.c
ip_sockglue.c ipv4: add ip_sock_set_pktinfo 2020-05-28 11:11:45 -07:00
ip_tunnel_core.c
ip_tunnel.c net: add a new ndo_tunnel_ioctl method 2020-05-19 15:45:11 -07:00
ip_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
ipcomp.c
ipconfig.c
ipip.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-24 13:47:27 -07:00
ipmr_base.c
ipmr.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-24 13:47:27 -07:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile
metrics.c
netfilter.c
netlink.c
nexthop.c nexthop: Fix fdb labeling for groups 2020-06-10 13:18:40 -07:00
ping.c
proc.c
protocol.c
raw_diag.c
raw.c
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-24 13:47:27 -07:00
syncookies.c
sysctl_net_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-05-01 17:02:27 -07:00
tcp_bbr.c
tcp_bic.c
tcp_bpf.c bpf: tcp: Recv() should return 0 when the peer socket is closed 2020-06-12 15:10:12 -07:00
tcp_cdg.c
tcp_cong.c
tcp_cubic.c
tcp_dctcp.c
tcp_dctcp.h
tcp_diag.c
tcp_fastopen.c
tcp_highspeed.c
tcp_htcp.c
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: grow window for OOO packets only for SACK flows 2020-06-16 13:38:19 -07:00
tcp_ipv4.c tcp: ipv6: support RFC 6069 (TCP-LD) 2020-05-28 11:02:46 -07:00
tcp_lp.c
tcp_metrics.c
tcp_minisocks.c mptcp: add new sock flag to deal with join subflows 2020-05-15 12:30:13 -07:00
tcp_nv.c
tcp_offload.c
tcp_output.c tcp: defer xmit timer reset in tcp_xmit_retransmit_queue() 2020-05-06 17:29:38 -07:00
tcp_rate.c
tcp_recovery.c
tcp_scalable.c
tcp_timer.c tcp: add tp->dup_ack_counter 2020-04-30 13:24:01 -07:00
tcp_ulp.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-13 16:27:13 -07:00
tunnel4.c
udp_bpf.c
udp_diag.c
udp_impl.h
udp_offload.c
udp_tunnel.c net: Make locking in sock_bindtoindex optional 2020-06-01 14:57:14 -07:00
udp.c xfrm: add support for UDPv6 encapsulation of ESP 2020-04-28 11:28:36 +02:00
udplite.c
xfrm4_input.c xfrm: state: remove extract_input indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_output.c xfrm: fix unused variable warning if CONFIG_NETFILTER=n 2020-05-11 15:12:27 +02:00
xfrm4_policy.c
xfrm4_protocol.c
xfrm4_state.c xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_tunnel.c