diff options
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 17 | ||||
| -rw-r--r-- | include/linux/tcp.h | 6 | ||||
| -rw-r--r-- | include/net/tcp.h | 4 | ||||
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 7 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 375 | ||||
| -rw-r--r-- | net/ipv4/tcp_minisocks.c | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 11 | ||||
| -rw-r--r-- | net/ipv4/tcp_timer.c | 6 | ||||
| -rw-r--r-- | net/ipv4/tcp_westwood.c | 2 |
9 files changed, 10 insertions, 421 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 17953e2bc3e9..8a977a0aaede 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -239,23 +239,6 @@ tcp_frto - INTEGER interacts badly with the packet counting of the SACK enabled TCP flow. -tcp_frto_response - INTEGER - When F-RTO has detected that a TCP retransmission timeout was - spurious (i.e, the timeout would have been avoided had TCP set a - longer retransmission timeout), TCP has several options what to do - next. Possible values are: - 0 Rate halving based; a smooth and conservative response, - results in halved cwnd and ssthresh after one RTT - 1 Very conservative response; not recommended because even - though being valid, it interacts poorly with the rest of - Linux TCP, halves cwnd and ssthresh immediately - 2 Aggressive response; undoes congestion control measures - that are now known to be unnecessary (ignoring the - possibility of a lost retransmission that would require - TCP to be more cautious), cwnd and ssthresh are restored - to the values prior timeout - Default: 0 (rate halving based) - tcp_keepalive_time - INTEGER How often TCP sends out keepalive messages when keepalive is enabled. Default: 2hours. diff --git a/include/linux/tcp.h b/include/linux/tcp.h index ed6a7456eecd..f5f203b36379 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -187,14 +187,12 @@ struct tcp_sock { u32 window_clamp; /* Maximal window to advertise */ u32 rcv_ssthresh; /* Current window clamp */ - u32 frto_highmark; /* snd_nxt when RTO occurred */ u16 advmss; /* Advertised MSS */ - u8 frto_counter; /* Number of new acks after RTO */ + u8 unused; u8 nonagle : 4,/* Disable Nagle algorithm? */ thin_lto : 1,/* Use linear timeouts for thin streams */ thin_dupack : 1,/* Fast retransmit on first dupack */ - repair : 1, - unused : 1; + repair : 1; u8 repair_queue; u8 do_early_retrans:1,/* Enable RFC5827 early-retransmit */ syn_data:1, /* SYN includes data */ diff --git a/include/net/tcp.h b/include/net/tcp.h index 7f2f17198d75..d1dcb596230e 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -272,7 +272,6 @@ extern int sysctl_tcp_app_win; extern int sysctl_tcp_adv_win_scale; extern int sysctl_tcp_tw_reuse; extern int sysctl_tcp_frto; -extern int sysctl_tcp_frto_response; extern int sysctl_tcp_low_latency; extern int sysctl_tcp_dma_copybreak; extern int sysctl_tcp_nometrics_save; @@ -424,8 +423,6 @@ extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb, bool fastopen); extern int tcp_child_process(struct sock *parent, struct sock *child, struct sk_buff *skb); -extern bool tcp_use_frto(struct sock *sk); -extern void tcp_enter_frto(struct sock *sk); extern void tcp_enter_loss(struct sock *sk, int how); extern void tcp_clear_retrans(struct tcp_sock *tp); extern void tcp_update_metrics(struct sock *sk); @@ -756,7 +753,6 @@ enum tcp_ca_event { CA_EVENT_TX_START, /* first transmit when no packets in flight */ CA_EVENT_CWND_RESTART, /* congestion window restart */ CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ - CA_EVENT_FRTO, /* fast recovery timeout */ CA_EVENT_LOSS, /* loss timeout */ CA_EVENT_FAST_ACK, /* in sequence ack */ CA_EVENT_SLOW_ACK, /* other ack */ diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index cb45062c8be0..fa2f63fc453b 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -592,13 +592,6 @@ static struct ctl_table ipv4_table[] = { .proc_handler = proc_dointvec }, { - .procname = "tcp_frto_response", - .data = &sysctl_tcp_frto_response, - .maxlen = sizeof(int), - .mode = 0644, - .proc_handler = proc_dointvec - }, - { .procname = "tcp_low_latency", .data = &sysctl_tcp_low_latency, .maxlen = sizeof(int), diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 19f0149fb6a2..231c79fe91f3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -93,7 +93,6 @@ int sysctl_tcp_stdurg __read_mostly; int sysctl_tcp_rfc1337 __read_mostly; int sysctl_tcp_max_orphans __read_mostly = NR_FILE; int sysctl_tcp_frto __read_mostly = 2; -int sysctl_tcp_frto_response __read_mostly; int sysctl_tcp_thin_dupack __read_mostly; @@ -108,17 +107,14 @@ int sysctl_tcp_early_retrans __read_mostly = 3; #define FLAG_DATA_SACKED 0x20 /* New SACK. */ #define FLAG_ECE 0x40 /* ECE in this ACK */ #define FLAG_SLOWPATH 0x100 /* Do not skip RFC checks for window update.*/ -#define FLAG_ONLY_ORIG_SACKED 0x200 /* SACKs only non-rexmit sent before RTO */ #define FLAG_SND_UNA_ADVANCED 0x400 /* Snd_una was changed (!= FLAG_DATA_ACKED) */ #define FLAG_DSACKING_ACK 0x800 /* SACK blocks contained D-SACK info */ -#define FLAG_NONHEAD_RETRANS_ACKED 0x1000 /* Non-head rexmitted data was ACKed */ #define FLAG_SACK_RENEGING 0x2000 /* snd_una advanced to a sacked seq */ #define FLAG_ACKED (FLAG_DATA_ACKED|FLAG_SYN_ACKED) #define FLAG_NOT_DUP (FLAG_DATA|FLAG_WIN_UPDATE|FLAG_ACKED) #define FLAG_CA_ALERT (FLAG_DATA_SACKED|FLAG_ECE) #define FLAG_FORWARD_PROGRESS (FLAG_ACKED|FLAG_DATA_SACKED) -#define FLAG_ANY_PROGRESS (FLAG_FORWARD_PROGRESS|FLAG_SND_UNA_ADVANCED) #define TCP_REMNANT (TCP_FLAG_FIN|TCP_FLAG_URG|TCP_FLAG_SYN|TCP_FLAG_PSH) #define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH)) @@ -1159,10 +1155,6 @@ static u8 tcp_sacktag_one(struct sock *sk, tcp_highest_sack_seq(tp))) state->reord = min(fack_count, state->reord); - - /* SACK enhanced F-RTO (RFC4138; Appendix B) */ - if (!after(end_seq, tp->frto_highmark)) - state->flag |= FLAG_ONLY_ORIG_SACKED; } if (sacked & TCPCB_LOST) { @@ -1555,7 +1547,6 @@ static int tcp_sacktag_write_queue(struct sock *sk, const struct sk_buff *ack_skb, u32 prior_snd_una) { - const struct inet_connection_sock *icsk = inet_csk(sk); struct tcp_sock *tp = tcp_sk(sk); const unsigned char *ptr = (skb_transport_header(ack_skb) + TCP_SKB_CB(ack_skb)->sacked); @@ -1728,12 +1719,6 @@ walk: start_seq, end_seq, dup_sack); advance_sp: - /* SACK enhanced FRTO (RFC4138, Appendix B): Clearing correct - * due to in-order walk - */ - if (after(end_seq, tp->frto_highmark)) - state.flag &= ~FLAG_ONLY_ORIG_SACKED; - i++; } @@ -1750,8 +1735,7 @@ advance_sp: tcp_verify_left_out(tp); if ((state.reord < tp->fackets_out) && - ((icsk->icsk_ca_state != TCP_CA_Loss) || tp->undo_marker) && - (!tp->frto_highmark || after(tp->snd_una, tp->frto_highmark))) + ((inet_csk(sk)->icsk_ca_state != TCP_CA_Loss) || tp->undo_marker)) tcp_update_reordering(sk, tp->fackets_out - state.reord, 0); out: @@ -1825,197 +1809,6 @@ static inline void tcp_reset_reno_sack(struct tcp_sock *tp) tp->sacked_out = 0; } -static int tcp_is_sackfrto(const struct tcp_sock *tp) -{ - return (sysctl_tcp_frto == 0x2) && !tcp_is_reno(tp); -} - -/* F-RTO can only be used if TCP has never retransmitted anything other than - * head (SACK enhanced variant from Appendix B of RFC4138 is more robust here) - */ -bool tcp_use_frto(struct sock *sk) -{ - const struct tcp_sock *tp = tcp_sk(sk); - const struct inet_connection_sock *icsk = inet_csk(sk); - struct sk_buff *skb; - - if (!sysctl_tcp_frto) - return false; - - /* MTU probe and F-RTO won't really play nicely along currently */ - if (icsk->icsk_mtup.probe_size) - return false; - - if (tcp_is_sackfrto(tp)) - return true; - - /* Avoid expensive walking of rexmit queue if possible */ - if (tp->retrans_out > 1) - return false; - - skb = tcp_write_queue_head(sk); - if (tcp_skb_is_last(sk, skb)) - return true; - skb = tcp_write_queue_next(sk, skb); /* Skips head */ - tcp_for_write_queue_from(skb, sk) { - if (skb == tcp_send_head(sk)) - break; - if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS) - return false; - /* Short-circuit when first non-SACKed skb has been checked */ - if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) - break; - } - return true; -} - -/* RTO occurred, but do not yet enter Loss state. Instead, defer RTO - * recovery a bit and use heuristics in tcp_process_frto() to detect if - * the RTO was spurious. Only clear SACKED_RETRANS of the head here to - * keep retrans_out counting accurate (with SACK F-RTO, other than head - * may still have that bit set); TCPCB_LOST and remaining SACKED_RETRANS - * bits are handled if the Loss state is really to be entered (in - * tcp_enter_frto_loss). - * - * Do like tcp_enter_loss() would; when RTO expires the second time it - * does: - * "Reduce ssthresh if it has not yet been made inside this window." - */ -void tcp_enter_frto(struct sock *sk) -{ - const struct inet_connection_sock *icsk = inet_csk(sk); - struct tcp_sock *tp = tcp_sk(sk); - struct sk_buff *skb; - - if ((!tp->frto_counter && icsk->icsk_ca_state <= TCP_CA_Disorder) || - tp->snd_una == tp->high_seq || - ((icsk->icsk_ca_state == TCP_CA_Loss || tp->frto_counter) && - !icsk->icsk_retransmits)) { - tp->prior_ssthresh = tcp_current_ssthresh(sk); - /* Our state is too optimistic in ssthresh() call because cwnd - * is not reduced until tcp_enter_frto_loss() when previous F-RTO - * recovery has not yet completed. Pattern would be this: RTO, - * Cumulative ACK, RTO (2xRTO for the same segment does not end - * up here twice). - * RFC4138 should be more specific on what to do, even though - * RTO is quite unlikely to occur after the first Cumulative ACK - * due to back-off and complexity of triggering events ... - */ - if (tp->frto_counter) { - u32 stored_cwnd; - stored_cwnd = tp->snd_cwnd; - tp->snd_cwnd = 2; - tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk); - tp->snd_cwnd = stored_cwnd; - } else { - tp->snd_ssthresh = icsk->icsk_ca_ops->ssthresh(sk); - } - /* ... in theory, cong.control module could do "any tricks" in - * ssthresh(), which means that ca_state, lost bits and lost_out - * counter would have to be faked before the call occurs. We - * consider that too expensive, unlikely and hacky, so modules - * using these in ssthresh() must deal these incompatibility - * issues if they receives CA_EVENT_FRTO and frto_counter != 0 - */ - tcp_ca_event(sk, CA_EVENT_FRTO); - } - - tp->undo_marker = tp->snd_una; - tp->undo_retrans = 0; - - skb = tcp_write_queue_head(sk); - if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS) - tp->undo_marker = 0; - if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) { - TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; - tp->retrans_out -= tcp_skb_pcount(skb); - } - tcp_verify_left_out(tp); - - /* Too bad if TCP was application limited */ - tp->snd_cwnd = min(tp->snd_cwnd, tcp_packets_in_flight(tp) + 1); - - /* Earlier loss recovery underway (see RFC4138; Appendix B). - * The last condition is necessary at least in tp->frto_counter case. - */ - if (tcp_is_sackfrto(tp) && (tp->frto_counter || - ((1 << icsk->icsk_ca_state) & (TCPF_CA_Recovery|TCPF_CA_Loss))) && - after(tp->high_seq, tp->snd_una)) { - tp->frto_highmark = tp->high_seq; - } else { - tp->frto_highmark = tp->snd_nxt; - } - tcp_set_ca_state(sk, TCP_CA_Disorder); - tp->high_seq = tp->snd_nxt; - tp->frto_counter = 1; -} - -/* Enter Loss state after F-RTO was applied. Dupack arrived after RTO, - * which indicates that we should follow the traditional RTO recovery, - * i.e. mark everything lost and do go-back-N retransmission. - */ -static void tcp_enter_frto_loss(struct sock *sk, int allowed_segments, int flag) -{ - struct tcp_sock *tp = tcp_sk(sk); - struct sk_buff *skb; - - tp->lost_out = 0; - tp->retrans_out = 0; - if (tcp_is_reno(tp)) - tcp_reset_reno_sack(tp); - - tcp_for_write_queue(skb, sk) { - if (skb == tcp_send_head(sk)) - break; - - TCP_SKB_CB(skb)->sacked &= ~TCPCB_LOST; - /* - * Count the retransmission made on RTO correctly (only when - * waiting for the first ACK and did not get it)... - */ - if ((tp->frto_counter == 1) && !(flag & FLAG_DATA_ACKED)) { - /* For some reason this R-bit might get cleared? */ - if (TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_RETRANS) - tp->retrans_out += tcp_skb_pcount(skb); - /* ...enter this if branch just for the first segment */ - flag |= FLAG_DATA_ACKED; - } else { - if (TCP_SKB_CB(skb)->sacked & TCPCB_RETRANS) - tp->undo_marker = 0; - TCP_SKB_CB(skb)->sacked &= ~TCPCB_SACKED_RETRANS; - } - - /* Marking forward transmissions that were made after RTO lost - * can cause unnecessary retransmissions in some scenarios, - * SACK blocks will mitigate that in some but not in all cases. - * We used to not mark them but it was causing break-ups with - * receivers that do only in-order receival. - * - * TODO: we could detect presence of such receiver and select - * different behavior per flow. - */ - if (!(TCP_SKB_CB(skb)->sacked & TCPCB_SACKED_ACKED)) { - TCP_SKB_CB(skb)->sacked |= TCPCB_LOST; - tp->lost_out += tcp_skb_pcount(skb); - tp->retransmit_high = TCP_SKB_CB(skb)->end_seq; - } - } - tcp_verify_left_out(tp); - - tp->snd_cwnd = tcp_packets_in_flight(tp) + allowed_segments; - tp->snd_cwnd_cnt = 0; - tp->snd_cwnd_stamp = tcp_time_stamp; - tp->frto_counter = 0; - - tp->reordering = min_t(unsigned int, tp->reordering, - sysctl_tcp_reordering); - tcp_set_ca_state(sk, TCP_CA_Loss); - tp->high_seq = tp->snd_nxt; - TCP_ECN_queue_cwr(tp); - - tcp_clear_all_retrans_hints(tp); -} - static void tcp_clear_retrans_partial(struct tcp_sock *tp) { tp->retrans_out = 0; @@ -2090,8 +1883,6 @@ void tcp_enter_loss(struct sock *sk, int how) tcp_set_ca_state(sk, TCP_CA_Loss); tp->high_seq = tp->snd_nxt; TCP_ECN_queue_cwr(tp); - /* Abort F-RTO algorithm if one is in progress */ - tp->frto_counter = 0; } /* If ACK arrived pointing to a remembered SACK, it means that our @@ -2275,10 +2066,6 @@ static bool tcp_time_to_recover(struct sock *sk, int flag) struct tcp_sock *tp = tcp_sk(sk); __u32 packets_out; - /* Do not perform any recovery during F-RTO algorithm */ - if (tp->frto_counter) - return false; - /* Trick#1: The loss is proven. */ if (tp->lost_out) return true; @@ -2760,7 +2547,7 @@ static void tcp_try_to_open(struct sock *sk, int flag, int newly_acked_sacked) tcp_verify_left_out(tp); - if (!tp->frto_counter && !tcp_any_retrans_done(sk)) + if (!tcp_any_retrans_done(sk)) tp->retrans_stamp = 0; if (flag & FLAG_ECE) @@ -3198,8 +2985,6 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, flag |= FLAG_RETRANS_DATA_ACKED; ca_seq_rtt = -1; seq_rtt = -1; - if ((flag & FLAG_DATA_ACKED) || (acked_pcount > 1)) - flag |= FLAG_NONHEAD_RETRANS_ACKED; } else { ca_seq_rtt = now - scb->when; last_ackt = skb->tstamp; @@ -3408,150 +3193,6 @@ static int tcp_ack_update_window(struct sock *sk, const struct sk_buff *skb, u32 return flag; } -/* A very conservative spurious RTO response algorithm: reduce cwnd and - * continue in congestion avoidance. - */ -static void tcp_conservative_spur_to_response(struct tcp_sock *tp) -{ - tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_ssthresh); - tp->snd_cwnd_cnt = 0; - TCP_ECN_queue_cwr(tp); - tcp_moderate_cwnd(tp); -} - -/* A conservative spurious RTO response algorithm: reduce cwnd using - * PRR and continue in congestion avoidance. - */ -static void tcp_cwr_spur_to_response(struct sock *sk) -{ - tcp_enter_cwr(sk, 0); -} - -static void tcp_undo_spur_to_response(struct sock *sk, int flag) -{ - if (flag & FLAG_ECE) - tcp_cwr_spur_to_response(sk); - else - tcp_undo_cwr(sk, true); -} - -/* F-RTO spurious RTO detection algorithm (RFC4138) - * - * F-RTO affects during two new ACKs following RTO (well, almost, see inline - * comments). State (ACK number) is kept in frto_counter. When ACK advances - * window (but not to or beyond highest sequence sent before RTO): - * On First ACK, send two new segments out. - * On Second ACK, RTO was likely spurious. Do spurious response (response - * algorithm is not part of the F-RTO detection algorithm - * given in RFC4138 but can be selected separately). - * Otherwise (basically on duplicate ACK), RTO was (likely) caused by a loss - * and TCP falls back to conventional RTO recovery. F-RTO allows overriding - * of Nagle, this is done using frto_counter states 2 and 3, when a new data - * segment of any size sent during F-RTO, state 2 is upgraded to 3. - * - * Rationale: if the RTO was spurious, new ACKs should arrive from the - * original window even after we transmit two new data segments. - * - * SACK version: - * on first step, wait until first cumulative ACK arrives, then move to - * the second step. In second step, the next ACK decides. - * - * F-RTO is implemented (mainly) in four functions: - * - tcp_use_frto() is used to determine if TCP is can use F-RTO - * - tcp_enter_frto() prepares TCP state on RTO if F-RTO is used, it is - * called when tcp_use_frto() showed green light - * - tcp_process_frto() handles incoming ACKs during F-RTO algorithm - * - tcp_enter_frto_loss() is called if there is not enough evidence - * to prove that the RTO is indeed spurious. It transfers the control - * from F-RTO to the conventional RTO recovery - */ -static bool tcp_process_frto(struct sock *sk, int flag) -{ - struct tcp_sock *tp = tcp_sk(sk); - - tcp_verify_left_out(tp); - - /* Duplicate the behavior from Loss state (fastretrans_alert) */ - if (flag & FLAG_DATA_ACKED) - inet_csk(sk)->icsk_retransmits = 0; - - if ((flag & FLAG_NONHEAD_RETRANS_ACKED) || - ((tp->frto_counter >= 2) && (flag & FLAG_RETRANS_DATA_ACKED))) - tp->undo_marker = 0; - - if (!before(tp->snd_una, tp->frto_highmark)) { - tcp_enter_frto_loss(sk, (tp->frto_counter == 1 ? 2 : 3), flag); - return true; - } - - if (!tcp_is_sackfrto(tp)) { - /* RFC4138 shortcoming in step 2; should also have case c): - * ACK isn't duplicate nor advances window, e.g., opposite dir - * data, winupdate - */ - if (!(flag & FLAG_ANY_PROGRESS) && (flag & FLAG_NOT_DUP)) - return true; - - if (!(flag & FLAG_DATA_ACKED)) { - tcp_enter_frto_loss(sk, (tp->frto_counter == 1 ? 0 : 3), - flag); - return true; - } - } else { - if (!(flag & FLAG_DATA_ACKED) && (tp->frto_counter == 1)) { - if (!tcp_packets_in_flight(tp)) { - tcp_enter_frto_loss(sk, 2, flag); - return true; - } - - /* Prevent sending of new data. */ - tp->snd_cwnd = min(tp->snd_cwnd, - tcp_packets_in_flight(tp)); - return true; - } - - if ((tp->frto_counter >= 2) && - (!(flag & FLAG_FORWARD_PROGRESS) || - ((flag & FLAG_DATA_SACKED) && - !(flag & FLAG_ONLY_ORIG_SACKED)))) { - /* RFC4138 shortcoming (see comment above) */ - if (!(flag & FLAG_FORWARD_PROGRESS) && - (flag & FLAG_NOT_DUP)) - return true; - - tcp_enter_frto_loss(sk, 3, flag); - return true; - } - } - - if (tp->frto_counter == 1) { - /* tcp_may_send_now needs to see updated state */ - tp->snd_cwnd = tcp_packets_in_flight(tp) + 2; - tp->frto_counter = 2; - - if (!tcp_may_send_now(sk)) - tcp_enter_frto_loss(sk, 2, flag); - - return true; - } else { - switch (sysctl_tcp_frto_response) { - case 2: - tcp_undo_spur_to_response(sk, flag); - break; - case 1: - tcp_conservative_spur_to_response(tp); - break; - default: - tcp_cwr_spur_to_response(sk); - break; - } - tp->frto_counter = 0; - tp->undo_marker = 0; - NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPSPURIOUSRTOS); - } - return false; -} - /* RFC 5961 7 [ACK Throttling] */ static void tcp_send_challenge_ack(struct sock *sk) { @@ -3616,7 +3257,6 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) int prior_packets; int prior_sacked = tp->sacked_out; int pkts_acked = 0; - bool frto_cwnd = false; /* If the ack is older than previous acks * then we can probably ignore it. @@ -3690,22 +3330,15 @@ static int tcp_ack(struct sock *sk, const struct sk_buff *skb, int flag) pkts_acked = prior_packets - tp->packets_out; - if (tp->frto_counter) - frto_cwnd = tcp_process_frto(sk, flag); - /* Guarantee sacktag reordering detection against wrap-arounds */ - if (before(tp->frto_highmark, tp->snd_una)) - tp->frto_highmark = 0; - if (tcp_ack_is_dubious(sk, flag)) { /* Advance CWND, if state allows this. */ - if ((flag & FLAG_DATA_ACKED) && !frto_cwnd && - tcp_may_raise_cwnd(sk, flag)) + if ((flag & FLAG_DATA_ACKED) && tcp_may_raise_cwnd(sk, flag)) tcp_cong_avoid(sk, ack, prior_in_flight); is_dupack = !(flag & (FLAG_SND_UNA_ADVANCED | FLAG_NOT_DUP)); tcp_fastretrans_alert(sk, pkts_acked, prior_sacked, is_dupack, flag); } else { - if ((flag & FLAG_DATA_ACKED) && !frto_cwnd) + if (flag & FLAG_DATA_ACKED) tcp_cong_avoid(sk, ack, prior_in_flight); } diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 8f0234f8bb95..05eaf8904613 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -422,9 +422,6 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, newtp->snd_cwnd = TCP_INIT_CWND; newtp->snd_cwnd_cnt = 0; - newtp->frto_counter = 0; - newtp->frto_highmark = 0; - if (newicsk->icsk_ca_ops != &tcp_init_congestion_ops && !try_module_get(newicsk->icsk_ca_ops->owner)) newicsk->icsk_ca_ops = &tcp_init_congestion_ops; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index e787ecec505e..163cf5fc0119 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -78,10 +78,6 @@ static void tcp_event_new_data_sent(struct sock *sk, const struct sk_buff *skb) tcp_advance_send_head(sk, skb); tp->snd_nxt = TCP_SKB_CB(skb)->end_seq; - /* Don't override Nagle indefinitely with F-RTO */ - if (tp->frto_counter == 2) - tp->frto_counter = 3; - tp->packets_out += tcp_skb_pcount(skb); if (!prior_packets || icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS || icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) @@ -1470,11 +1466,8 @@ static inline bool tcp_nagle_test(const struct tcp_sock *tp, const struct sk_buf if (nonagle & TCP_NAGLE_PUSH) return true; - /* Don't use the nagle rule for urgent data (or for the final FIN). - * Nagle can be ignored during F-RTO too (see RFC4138). - */ - if (tcp_urg_mode(tp) || (tp->frto_counter == 2) || - (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) + /* Don't use the nagle rule for urgent data (or for the final FIN). */ + if (tcp_urg_mode(tp) || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) return true; if (!tcp_nagle_check(tp, skb, cur_mss, nonagle)) diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index eeccf795e917..4b85e6f636c9 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -416,11 +416,7 @@ void tcp_retransmit_timer(struct sock *sk) NET_INC_STATS_BH(sock_net(sk), mib_idx); } - if (tcp_use_frto(sk)) { - tcp_enter_frto(sk); - } else { - tcp_enter_loss(sk, 0); - } + tcp_enter_loss(sk, 0); if (tcp_retransmit_skb(sk, tcp_write_queue_head(sk)) > 0) { /* Retransmission failed because of local congestion, diff --git a/net/ipv4/tcp_westwood.c b/net/ipv4/tcp_westwood.c index 1b91bf48e277..76a1e23259e1 100644 --- a/net/ipv4/tcp_westwood.c +++ b/net/ipv4/tcp_westwood.c @@ -236,7 +236,7 @@ static void tcp_westwood_event(struct sock *sk, enum tcp_ca_event event) tp->snd_cwnd = tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk); break; - case CA_EVENT_FRTO: + case CA_EVENT_LOSS: tp->snd_ssthresh = tcp_westwood_bw_rttmin(sk); /* Update RTT_min when next ack arrives */ w->reset_rtt_min = 1; |