linux/include/net
Soheil Hassas Yeganeh d7722e8570 tcp: track application-limited rate samples
This commit adds code to track whether the delivery rate represented
by each rate_sample was limited by the application.

Upon each transmit, we store in the is_app_limited field in the skb a
boolean bit indicating whether there is a known "bubble in the pipe":
a point in the rate sample interval where the sender was
application-limited, and did not transmit even though the cwnd and
pacing rate allowed it.

This logic marks the flow app-limited on a write if *all* of the
following are true:

  1) There is less than 1 MSS of unsent data in the write queue
     available to transmit.

  2) There is no packet in the sender's queues (e.g. in fq or the NIC
     tx queue).

  3) The connection is not limited by cwnd.

  4) There are no lost packets to retransmit.

The tcp_rate_check_app_limited() code in tcp_rate.c determines whether
the connection is application-limited at the moment. If the flow is
application-limited, it sets the tp->app_limited field. If the flow is
application-limited then that means there is effectively a "bubble" of
silence in the pipe now, and this silence will be reflected in a lower
bandwidth sample for any rate samples from now until we get an ACK
indicating this bubble has exited the pipe: specifically, until we get
an ACK for the next packet we transmit.

When we send every skb we record in scb->tx.is_app_limited whether the
resulting rate sample will be application-limited.

The code in tcp_rate_gen() checks to see when it is safe to mark all
known application-limited bubbles of silence as having exited the
pipe. It does this by checking to see when the delivered count moves
past the tp->app_limited marker. At this point it zeroes the
tp->app_limited marker, as all known bubbles are out of the pipe.

We make room for the tx.is_app_limited bit in the skb by borrowing a
bit from the in_flight field used by NV to record the number of bytes
in flight. The receive window in the TCP header is 16 bits, and the
max receive window scaling shift factor is 14 (RFC 1323). So the max
receive window offered by the TCP protocol is 2^(16+14) = 2^30. So we
only need 30 bits for the tx.in_flight used by NV.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-21 00:23:00 -04:00
..
9p 9p: switch p9_client_read() to passing struct iov_iter * 2015-04-11 22:28:27 -04:00
bluetooth Bluetooth: Add support for appearance in scan rsp 2016-09-19 20:19:34 +02:00
caif caif: fix a signedness bug in cfpkt_iterate() 2015-02-20 17:35:14 -05:00
irda irda: Convert function pointer arrays and uses to const 2014-12-10 15:33:16 -05:00
iucv s390/iucv: do not use arrays as argument 2015-09-21 16:03:04 -07:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-09-12 15:52:44 -07:00
netns Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2016-09-08 13:09:41 -07:00
nfc NFC: digital: Add support for NFC DEP Response Waiting Time 2016-07-11 02:01:14 +02:00
phonet sock: struct proto hash function may error 2016-02-11 03:54:14 -05:00
sctp sctp: make sctp_outq_flush/tail/uncork return void 2016-09-18 22:02:33 -04:00
tc_act net sched ife action: add 16 bit helpers 2016-09-19 21:55:28 -04:00
6lowpan.h 6lowpan: add 802.15.4 short addr slaac 2016-06-15 20:41:22 -07:00
Space.h
act_api.h net_sched: convert tcf_exts from list to pointer array 2016-08-17 19:27:51 -04:00
addrconf.h ipv6: export several functions 2016-06-15 20:41:23 -07:00
af_ieee802154.h ieee802154: af_ieee802154: fix typo in comment. 2015-09-17 13:20:05 +02:00
af_rxrpc.h rxrpc: Rewrite the data and ack handling code 2016-09-08 11:10:12 +01:00
af_unix.h af_unix: split 'u->readlock' into two: 'iolock' and 'bindlock' 2016-09-04 13:29:29 -07:00
af_vsock.h VSOCK: Introduce virtio_vsock_common.ko 2016-08-02 02:57:29 +03:00
ah.h
arp.h neigh: Factor out ___neigh_lookup_noref 2015-03-04 00:23:23 -05:00
atmclip.h
ax25.h ax25: Stop using sock->sk_protinfo. 2015-06-28 16:55:44 -07:00
ax88796.h
bond_3ad.h bonding: 3ad: apply ad_actor settings changes immediately 2016-02-09 04:45:49 -05:00
bond_alb.h net: Move bonding headers under include/net 2014-11-10 13:27:49 -05:00
bond_options.h bonding: convert num_grat_arp to the new bonding option API 2015-07-27 01:05:24 -07:00
bonding.h bonding: prevent out of bound accesses 2016-07-01 06:06:09 -04:00
busy_poll.h net: un-inline sk_busy_loop() 2015-11-18 16:17:38 -05:00
calipso.h calipso: Add a label cache. 2016-06-27 15:06:17 -04:00
cfg80211-wext.h
cfg80211.h This time we have various things - all across the board: 2016-09-18 22:29:08 -04:00
cfg802154.h ieee802154: add netns support 2016-07-08 12:20:57 +02:00
checksum.h csum: Update csum_block_add to use rotate instead of byteswap 2016-03-13 15:01:00 -04:00
cipso_ipv4.h cipso: don't use IPCB() to locate the CIPSO IP option 2015-02-11 14:46:37 -05:00
cls_cgroup.h cls_cgroup: get sk_classid only from full sockets 2016-04-19 20:09:25 -04:00
codel.h codel: split into multiple files 2016-04-25 16:44:27 -04:00
codel_impl.h codel: split into multiple files 2016-04-25 16:44:27 -04:00
codel_qdisc.h net_sched: fq_codel: cache skb->truesize into skb->cb 2016-06-25 12:19:35 -04:00
compat.h packet: compat support for sock_fprog 2016-06-09 23:41:03 -07:00
datalink.h
dcbevent.h
dcbnl.h net/dcb: Add IEEE QCN attribute 2015-03-06 21:50:02 -05:00
devlink.h devlink: remove unused priv_size 2016-08-26 11:55:18 -07:00
dn.h
dn_dev.h
dn_fib.h
dn_neigh.h netfilter: Pass net into okfn 2015-09-17 17:18:37 -07:00
dn_nsp.h
dn_route.h
dsa.h net-next: dsa: add Qualcomm tag RX/TX handler 2016-09-16 04:31:51 -04:00
dsfield.h
dst.h route: move lwtunnel state to a single place 2016-04-25 16:20:09 -04:00
dst_cache.h net: add dst_cache support 2016-02-16 20:21:48 -05:00
dst_metadata.h net/dst: Utility functions to build dst_metadata without supplying an skb 2016-09-10 20:53:55 -07:00
dst_ops.h ipv4, ipv6: Pass net into __ip_local_out and __ip6_local_out 2015-10-08 04:27:02 -07:00
esp.h
ethoc.h net/ethoc: support big-endian register layout 2015-09-23 15:33:15 -07:00
fib_rules.h net: Add l3mdev rule 2016-06-08 11:36:02 -07:00
firewire.h
flow.h net: flow: Remove FLOWI_FLAG_L3MDEV_SRC flag 2016-09-10 23:12:53 -07:00
flow_dissector.h rps: flow_dissector: Add the const for the parameter of flow_keys_have_l4 2016-09-01 16:51:08 -07:00
flowcache.h
fou.h fou: Add encap ops for IPv6 tunnels 2016-05-20 18:03:16 -04:00
fq.h fq: add fair queuing framework 2016-04-25 16:45:53 -04:00
fq_impl.h fq: split out backlog update logic 2016-04-28 17:03:38 -04:00
garp.h
gen_stats.h net: sched: do not acquire qdisc spinlock in qdisc/class stats dump 2016-06-07 16:37:14 -07:00
genetlink.h Revert "genl: Add genlmsg_new_unicast() for unicast message allocation" 2016-02-18 11:42:19 -05:00
geneve.h net: Remove deprecated tunnel specific UDP offload functions 2016-06-17 20:23:32 -07:00
gre.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-08-18 01:17:32 -04:00
gro_cells.h gro_cells: gro_cells_receive now return error code 2016-07-22 00:50:41 -04:00
gtp.h gtp: #define #define _GTP_H_ and not #define _GTP_H 2016-07-25 17:55:43 -07:00
gue.h gue: Protocol constants for remote checksum offload 2014-11-05 16:30:03 -05:00
hwbm.h net: add a hardware buffer management helper API 2016-03-14 12:19:46 -04:00
icmp.h net: snmp: kill STATS_BH macros 2016-04-27 22:48:25 -04:00
ieee80211_radiotap.h mac80211: add support for radiotap timestamp field 2016-09-12 11:45:45 +02:00
ieee802154_netdev.h mac802154: constify ieee802154_llsec_ops structure 2016-01-04 20:40:41 +01:00
if_inet6.h ipv6: do retries on stable privacy addresses 2015-03-23 22:12:09 -04:00
ila.h ila: Add generic ILA translation facility 2015-12-15 23:25:20 -05:00
inet6_connection_sock.h ipv6: remove unused in6_addr struct 2016-03-22 15:45:44 -04:00
inet6_hashtables.h tcp/dccp: do not touch listener sk_refcnt under synflood 2016-04-04 22:11:20 -04:00
inet_common.h ip4ip6: Support for GSO/GRO 2016-05-20 18:03:17 -04:00
inet_connection_sock.h tcp/dccp: fix another race at listener dismantle 2016-02-18 11:35:51 -05:00
inet_ecn.h ipv6: suppress sparse warnings in IP6_ECN_set_ce() 2016-08-13 15:08:00 -07:00
inet_frag.h ipv4: namespacify ip fragment max dist sysctl knob 2016-02-16 20:42:54 -05:00
inet_hashtables.h tcp/dccp: do not touch listener sk_refcnt under synflood 2016-04-04 22:11:20 -04:00
inet_sock.h ipv6: Allow request socks to contain IPv6 options. 2016-06-27 15:05:28 -04:00
inet_timewait_sock.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-20 06:08:27 -07:00
inetpeer.h inet: tcp: fix inetpeer_set_addr_v4() 2015-12-16 00:14:12 -05:00
ip.h net/ipv4: Introduce IPSKB_FRAG_SEGS bit to inet_skb_parm.flags 2016-07-19 16:40:22 -07:00
ip6_checksum.h ipv6: Pass proto to csum_ipv6_magic as __u8 instead of unsigned short 2016-03-13 23:55:13 -04:00
ip6_fib.h ipv6: Check rt->dst.from for the DST_NOCACHE route 2015-11-15 17:12:37 -05:00
ip6_route.h ipv6: Export p6_route_input_lookup symbol 2016-09-19 01:25:22 -04:00
ip6_tunnel.h ip6_tunnel: add collect_md mode to IPv6 tunnels 2016-09-17 10:13:07 -04:00
ip_fib.h net: Don't delete routes in different VRFs 2016-09-06 13:56:13 -07:00
ip_tunnels.h ip_tunnel: add collect_md mode to IPIP tunnel 2016-09-17 10:13:07 -04:00
ip_vs.h ipvs: update real-server binding of outgoing connections in SIP-pe 2016-06-06 09:47:25 +09:00
ipcomp.h
ipconfig.h
ipv6.h Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
ipx.h switch ipxrtr_route_packet() from iovec to msghdr 2014-11-24 04:28:49 -05:00
iw_handler.h cfg80211/wext: fix message ordering 2016-01-29 17:13:43 +01:00
kcm.h kcm: Use stream parser 2016-08-17 19:36:23 -04:00
l3mdev.h net: l3mdev: Remove netif_index_is_l3_master 2016-09-17 10:05:05 -04:00
lapb.h
lib80211.h lib80211: remove unused print_ssid() 2014-10-14 02:18:27 +02:00
llc.h
llc_c_ac.h
llc_c_ev.h
llc_c_st.h llc: Make llc_conn_ev_qfyr_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_conn.h net: Pass kern from net_proto_family.create to sk_alloc 2015-05-11 10:50:17 -04:00
llc_if.h
llc_pdu.h
llc_s_ac.h
llc_s_ev.h
llc_s_st.h llc: Make llc_sap_action_t function pointer arrays const 2014-12-10 15:21:24 -05:00
llc_sap.h
lwtunnel.h net: lwtunnel: Handle fragmentation 2016-08-30 22:27:18 -07:00
mac80211.h mac80211: allow driver to handle packet-loss mechanism 2016-09-15 16:46:20 +02:00
mac802154.h ieee802154: cleanup WARN_ON for fc fetch 2016-07-08 13:23:12 +02:00
mip6.h
mld.h
mpls.h openvswitch: Add basic MPLS support to kernel 2014-11-05 23:52:33 -08:00
mpls_iptunnel.h mpls: multipath route support 2015-10-23 06:26:42 -07:00
mrp.h
ncsi.h net/ncsi: Package and channel management 2016-07-19 20:49:17 -07:00
ndisc.h 6lowpan: introduce 6lowpan-nd 2016-06-15 20:41:23 -07:00
neighbour.h net: add explicit logging and stat for neighbour table overflow 2015-08-10 13:46:21 -07:00
net_namespace.h treewide: replace obsolete _refok by __ref 2016-08-02 17:31:41 -04:00
net_ratelimit.h
netevent.h neigh: Send a notification when DELAY_PROBE_TIME changes 2016-07-05 09:06:29 -07:00
netlabel.h netlabel: Implement CALIPSO config functions for SMACK. 2016-06-27 15:06:18 -04:00
netlink.h netlink: kill nla_put_u64() 2016-05-16 13:46:23 -04:00
netprio_cgroup.h net: wrap sock->sk_cgrp_prioidx and ->sk_classid inside a struct 2015-12-08 22:02:33 -05:00
netrom.h
nexthop.h
nl802154.h ieee802154: add netns support 2016-07-08 12:20:57 +02:00
p8022.h
ping.h net: ping: make ping_v6_sendmsg static 2016-03-23 22:09:58 -04:00
pkt_cls.h net_sched: properly handle failure case of tcf_exts_init() 2016-08-22 17:02:31 -07:00
pkt_sched.h net: sched: convert qdisc linked list to hashtable 2016-08-10 17:19:02 -07:00
pptp.h pptp: Refactor the struct and macros of PPTP codes 2016-08-15 10:55:53 -07:00
protocol.h udp: Remove udp_offloads 2016-04-07 16:53:30 -04:00
psnap.h
raw.h sock: struct proto hash function may error 2016-02-11 03:54:14 -05:00
rawv6.h
red.h
regulatory.h cfg80211: allow wiphy specific regdomain management 2014-12-17 11:49:55 +01:00
request_sock.h inet: reqsk_alloc() needs to take care of dead listeners 2016-04-04 22:11:19 -04:00
rose.h
route.h net: ipv4: Remove l3mdev_get_saddr 2016-09-10 23:12:53 -07:00
rtnetlink.h net: rtnetlink: add support for the IFLA_STATS_LINK_XSTATS_SLAVE attribute 2016-06-30 06:15:04 -04:00
sch_generic.h sched: add and use qdisc_skb_head helpers 2016-09-19 01:47:18 -04:00
scm.h unix: correctly track in-flight fds in sending process user_struct 2016-02-08 10:30:42 -05:00
secure_seq.h
slhc_vj.h
snmp.h net: snmp: fix 64bit stats on 32bit arches 2016-04-28 11:49:45 -04:00
sock.h net: remove clear_sk() method 2016-08-23 23:25:29 -07:00
sock_reuseport.h soreuseport: fix NULL ptr dereference SO_REUSEPORT after bind 2016-01-19 14:44:23 -05:00
stp.h
strparser.h kcm: Remove TCP specific references from kcm and strparser 2016-08-28 23:32:41 -04:00
switchdev.h switchdev: Fix return value of switchdev_port_fdb_dump(). 2016-09-02 11:00:21 -07:00
tcp.h tcp: track application-limited rate samples 2016-09-21 00:23:00 -04:00
tcp_states.h inet: add TCP_NEW_SYN_RECV state 2015-03-12 22:58:12 -04:00
timewait_sock.h inet: remove BUG_ON() in twsk_destructor() 2015-07-09 15:12:20 -07:00
transp_v6.h ipv6: add new struct ipcm6_cookie 2016-05-03 16:08:14 -04:00
tso.h net: tso: add support for IPv6 2015-10-26 22:24:22 -07:00
udp.h net: diag: support SOCK_DESTROY for UDP sockets 2016-08-23 23:12:27 -07:00
udp_tunnel.h vxlan: Add new UDP encapsulation offload type for VXLAN-GPE 2016-06-17 20:23:32 -07:00
udplite.h net: switch memcpy_fromiovec()/memcpy_fromiovecend() users to copy_from_iter() 2015-02-04 01:34:15 -05:00
vsock_addr.h
vxlan.h net/ip_tunnels: Introduce tunnel_id_to_key32() and key32_to_tunnel_id() 2016-09-10 20:53:55 -07:00
wext.h
wimax.h
x25.h
x25device.h
xfrm.h xfrm: constify xfrm_replay structures 2016-08-10 11:18:49 +02:00