linux-stable/net/ipv4
Jason Xing e4dd0d3a2f net: fix the RTO timer retransmitting skb every 1ms if linear option is enabled
In the real workload, I encountered an issue which could cause the RTO
timer to retransmit the skb per 1ms with linear option enabled. The amount
of lost-retransmitted skbs can go up to 1000+ instantly.

The root cause is that if the icsk_rto happens to be zero in the 6th round
(which is the TCP_THIN_LINEAR_RETRIES value), then it will always be zero
due to the changed calculation method in tcp_retransmit_timer() as follows:

icsk->icsk_rto = min(icsk->icsk_rto << 1, TCP_RTO_MAX);

Above line could be converted to
icsk->icsk_rto = min(0 << 1, TCP_RTO_MAX) = 0

Therefore, the timer expires so quickly without any doubt.

I read through the RFC 6298 and found that the RTO value can be rounded
up to a certain value, in Linux, say TCP_RTO_MIN as default, which is
regarded as the lower bound in this patch as suggested by Eric.

Fixes: 36e31b0af5 ("net: TCP thin linear timeouts")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-15 20:24:04 +01:00
..
bpfilter net: Use umd_cleanup_helper() 2023-05-31 13:06:57 +02:00
netfilter xtables: move icmp/icmpv6 logic to xt_tcpudp 2023-03-22 21:48:59 +01:00
af_inet.c sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
ah4.c net: ipv4: Remove completion function scaffolding 2023-02-13 18:35:15 +08:00
arp.c neighbour: annotate lockless accesses to n->nud_state 2023-03-15 00:37:32 -07:00
bpf_tcp_ca.c bpf: Remove unused arguments from btf_struct_access(). 2023-04-04 16:57:10 -07:00
cipso_ipv4.c cipso_ipv4: use iph_set_totlen in skbuff_setattr 2023-02-01 20:54:27 -08:00
datagram.c Networking fixes for 6.1-rc2, including fixes from netfilter 2022-10-20 17:24:59 -07:00
devinet.c net: ipv4: Allow changing IPv4 address protocol 2023-03-23 08:32:52 +00:00
esp4.c net: ipv4: Use kfree_sensitive instead of kfree 2023-07-19 11:03:03 +01:00
esp4_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-06-22 18:40:38 -07:00
fib_frontend.c ipv4: Fix incorrect table ID in IOCTL path 2023-03-16 17:26:31 -07:00
fib_lookup.h
fib_notifier.c
fib_rules.c ipv4: remove unnecessary type castings 2022-04-30 15:12:58 +01:00
fib_semantics.c neighbour: switch to standard rcu, instead of rcu_bh 2023-03-21 21:32:18 -07:00
fib_trie.c ipv4: Fix error return code in fib_table_insert() 2022-11-22 20:18:20 -08:00
fou_bpf.c bpf,fou: Add bpf_skb_{set,get}_fou_encap kfuncs 2023-04-12 16:40:39 -07:00
fou_core.c bpf,fou: Add bpf_skb_{set,get}_fou_encap kfuncs 2023-04-12 16:40:39 -07:00
fou_nl.c net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
fou_nl.h net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
gre_demux.c
gre_offload.c net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
icmp.c icmp: guard against too small mtu 2023-03-31 21:37:06 -07:00
igmp.c ipv4: constify ip_mc_sf_allow() socket argument 2023-03-17 08:56:37 +00:00
inet_connection_sock.c tcp: annotate data-races around icsk->icsk_syn_retries 2023-07-20 12:34:18 -07:00
inet_diag.c net: annotate data-races around sk->sk_mark 2023-07-29 18:13:41 +01:00
inet_fragment.c net: dropreason: add SKB_DROP_REASON_FRAG_REASM_TIMEOUT 2022-10-31 20:14:27 -07:00
inet_hashtables.c Revert "tcp: avoid the lookup process failing to get sk in ehash table" 2023-07-19 20:57:40 -07:00
inet_timewait_sock.c Revert "tcp: avoid the lookup process failing to get sk in ehash table" 2023-07-19 20:57:40 -07:00
inetpeer.c inetpeer: Fix data-races around sysctl. 2022-07-08 12:10:33 +01:00
ip_forward.c ip: Fix data-races around sysctl_ip_fwd_update_priority. 2022-07-15 11:49:55 +01:00
ip_fragment.c Revert "net: Remove low_thresh in ip defrag" 2023-05-16 20:46:30 -07:00
ip_gre.c ipv4: ip_gre: fix return value check in erspan_xmit() 2023-07-19 12:27:09 +01:00
ip_input.c net: add support for ipv4 big tcp 2023-02-01 20:54:27 -08:00
ip_options.c
ip_output.c udp: Fix __ip_append_data()'s handling of MSG_SPLICE_PAGES 2023-08-02 19:19:32 -07:00
ip_sockglue.c net: annotate data-races around sk->sk_priority 2023-07-29 18:13:41 +01:00
ip_tunnel.c bpf-next-for-netdev 2023-04-13 16:43:38 -07:00
ip_tunnel_core.c tunnels: fix kasan splat when generating ipv4 pmtu error 2023-08-04 18:24:52 -07:00
ip_vti.c ipv4: tunnels: use DEV_STATS_INC() 2022-11-16 12:48:44 +00:00
ipcomp.c xfrm: ipcomp: add extack to ipcomp{4,6}_init_state 2022-09-29 07:18:00 +02:00
ipconfig.c net: ipconfig: move ic_nameservers_fallback into #ifdef block 2023-05-22 11:17:55 +01:00
ipip.c ipip,ip_tunnel,sit: Add FOU support for externally controlled ipip devices 2023-04-12 16:40:39 -07:00
ipmr.c net: ioctl: Use kernel memory on protocol ioctl callbacks 2023-06-15 22:33:26 -07:00
ipmr_base.c ipmr: adopt rcu_read_lock() in mr_dump() 2022-06-24 11:34:38 +01:00
Kconfig tcp: configurable source port perturb table size 2022-11-16 13:02:04 +00:00
Makefile bpf,fou: Add bpf_skb_{set,get}_fou_encap kfuncs 2023-04-12 16:40:39 -07:00
metrics.c ipv4: prevent potential spectre v1 gadget in ip_metrics_convert() 2023-01-23 21:37:25 -08:00
netfilter.c netfilter: Use l3mdev flow key when re-routing mangled packets 2022-05-16 13:03:29 +02:00
netlink.c
nexthop.c nexthop: Fix infinite nexthop bucket dump when using maximum nexthop ID 2023-08-09 13:45:12 -07:00
ping.c ping: Stop using RTO_ONLINK. 2023-05-24 08:22:06 +01:00
proc.c icmp: Add counters for rate limits 2023-01-26 10:52:18 +01:00
protocol.c
raw.c net: annotate data-races around sk->sk_priority 2023-07-29 18:13:41 +01:00
raw_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-04-06 12:01:20 -07:00
route.c net: annotate data-races around sk->sk_mark 2023-07-29 18:13:41 +01:00
syncookies.c tcp: Set route scope properly in cookie_v4_check(). 2023-06-06 21:13:03 -07:00
sysctl_net_ipv4.c tcp: enforce receive buffer memory limits by allowing the tcp window to shrink 2023-06-17 09:53:53 +01:00
tcp.c tcp: annotate data-races around fastopenq.max_qlen 2023-07-20 12:34:18 -07:00
tcp_bbr.c bpf: Add __bpf_kfunc tag to all kfuncs 2023-02-02 00:25:14 +01:00
tcp_bic.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_bpf.c sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
tcp_cdg.c Random number generator fixes for Linux 6.1-rc1. 2022-10-16 15:27:07 -07:00
tcp_cong.c net: Update an existing TCP congestion control algorithm. 2023-03-22 22:53:00 -07:00
tcp_cubic.c bpf: Add __bpf_kfunc tag to all kfuncs 2023-02-02 00:25:14 +01:00
tcp_dctcp.c bpf: Add __bpf_kfunc tag to all kfuncs 2023-02-02 00:25:14 +01:00
tcp_dctcp.h
tcp_diag.c tcp: Access &tcp_hashinfo via net. 2022-09-20 10:21:49 -07:00
tcp_fastopen.c tcp: annotate data-races around fastopenq.max_qlen 2023-07-20 12:34:18 -07:00
tcp_highspeed.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_htcp.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_hybla.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_illinois.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_input.c tcp: annotate data races in __tcp_oow_rate_limited() 2023-07-03 09:25:02 +01:00
tcp_ipv4.c net: annotate data-races around sk->sk_priority 2023-07-29 18:13:41 +01:00
tcp_lp.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_metrics.c tcp_metrics: fix data-race in tcpm_suck_dst() vs fastopen 2023-08-03 10:58:24 -07:00
tcp_minisocks.c tcp: annotate data-races around tcp_rsk(req)->ts_recent 2023-07-18 19:45:27 -07:00
tcp_nv.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_offload.c net: move gso declarations and functions to their own files 2023-06-10 00:11:41 -07:00
tcp_output.c tcp: annotate data-races around tcp_rsk(req)->ts_recent 2023-07-18 19:45:27 -07:00
tcp_plb.c prandom: remove prandom_u32_max() 2022-12-20 03:13:45 +01:00
tcp_rate.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-04-28 13:02:01 -07:00
tcp_recovery.c tcp: preserve const qualifier in tcp_sk() 2023-03-18 12:23:34 +00:00
tcp_scalable.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_timer.c net: fix the RTO timer retransmitting skb every 1ms if linear option is enabled 2023-08-15 20:24:04 +01:00
tcp_ulp.c net/ulp: use consistent error code when blocking ULP 2023-01-19 09:26:16 -08:00
tcp_vegas.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_vegas.h
tcp_veno.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_westwood.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tcp_yeah.c tcp: add accessors to read/set tp->snd_cwnd 2022-04-06 12:05:41 -07:00
tunnel4.c
udp.c net: gro: fix misuse of CB in udp socket lookup 2023-07-29 17:10:27 +01:00
udp_bpf.c bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser() 2023-03-03 17:25:15 +01:00
udp_diag.c udp: Access &udp_table via net. 2022-11-16 09:43:35 +00:00
udp_impl.h sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
udp_offload.c net: gro: fix misuse of CB in udp socket lookup 2023-07-29 17:10:27 +01:00
udp_tunnel_core.c net/tunnel: wait until all sk_user_data reader finish before releasing the sock 2022-12-12 09:51:52 +00:00
udp_tunnel_nic.c udp_tunnel: Add checks for nla_nest_start() in __udp_tunnel_nic_dump_write() 2022-11-29 08:44:24 -08:00
udp_tunnel_stub.c
udplite.c sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
xfrm4_input.c xfrm: fix inbound ipv4/udp/esp packets to UDPv6 dualstack sockets 2023-06-09 08:16:34 +02:00
xfrm4_output.c
xfrm4_policy.c net: dst: fix missing initialization of rt_uncached 2023-04-21 20:26:56 -07:00
xfrm4_protocol.c net: xfrm: unexport __init-annotated xfrm4_protocol_init() 2022-06-08 10:10:13 -07:00
xfrm4_state.c
xfrm4_tunnel.c xfrm: tunnel: add extack to ipip_init_state, xfrm6_tunnel_init_state 2022-09-29 07:18:00 +02:00