diff options
| -rw-r--r-- | include/trace/events/rxrpc.h | 45 | ||||
| -rw-r--r-- | net/rxrpc/ar-internal.h | 71 | ||||
| -rw-r--r-- | net/rxrpc/call_event.c | 47 | ||||
| -rw-r--r-- | net/rxrpc/call_object.c | 13 | ||||
| -rw-r--r-- | net/rxrpc/conn_event.c | 1 | ||||
| -rw-r--r-- | net/rxrpc/input.c | 241 | ||||
| -rw-r--r-- | net/rxrpc/misc.c | 23 | ||||
| -rw-r--r-- | net/rxrpc/output.c | 34 | ||||
| -rw-r--r-- | net/rxrpc/recvmsg.c | 19 | ||||
| -rw-r--r-- | net/rxrpc/sendmsg.c | 7 |
10 files changed, 463 insertions, 38 deletions
diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index 56475497043d..ada12d00118c 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -570,6 +570,51 @@ TRACE_EVENT(rxrpc_retransmit, __entry->expiry) ); +TRACE_EVENT(rxrpc_congest, + TP_PROTO(struct rxrpc_call *call, struct rxrpc_ack_summary *summary, + rxrpc_serial_t ack_serial, enum rxrpc_congest_change change), + + TP_ARGS(call, summary, ack_serial, change), + + TP_STRUCT__entry( + __field(struct rxrpc_call *, call ) + __field(enum rxrpc_congest_change, change ) + __field(rxrpc_seq_t, hard_ack ) + __field(rxrpc_seq_t, top ) + __field(rxrpc_seq_t, lowest_nak ) + __field(rxrpc_serial_t, ack_serial ) + __field_struct(struct rxrpc_ack_summary, sum ) + ), + + TP_fast_assign( + __entry->call = call; + __entry->change = change; + __entry->hard_ack = call->tx_hard_ack; + __entry->top = call->tx_top; + __entry->lowest_nak = call->acks_lowest_nak; + __entry->ack_serial = ack_serial; + memcpy(&__entry->sum, summary, sizeof(__entry->sum)); + ), + + TP_printk("c=%p %08x %s %08x %s cw=%u ss=%u nr=%u,%u nw=%u,%u r=%u b=%u u=%u d=%u l=%x%s%s%s", + __entry->call, + __entry->ack_serial, + rxrpc_ack_names[__entry->sum.ack_reason], + __entry->hard_ack, + rxrpc_congest_modes[__entry->sum.mode], + __entry->sum.cwnd, + __entry->sum.ssthresh, + __entry->sum.nr_acks, __entry->sum.nr_nacks, + __entry->sum.nr_new_acks, __entry->sum.nr_new_nacks, + __entry->sum.nr_rot_new_acks, + __entry->top - __entry->hard_ack, + __entry->sum.cumulative_acks, + __entry->sum.dup_acks, + __entry->lowest_nak, __entry->sum.new_low_nack ? "!" : "", + rxrpc_congest_changes[__entry->change], + __entry->sum.retrans_timeo ? " rTxTo" : "") + ); + #endif /* _TRACE_RXRPC_H */ /* This part must be outside protection */ diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 042dbcc52654..ca96e547cb9a 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -402,6 +402,7 @@ enum rxrpc_call_flag { RXRPC_CALL_RX_LAST, /* Received the last packet (at rxtx_top) */ RXRPC_CALL_TX_LAST, /* Last packet in Tx buffer (at rxtx_top) */ RXRPC_CALL_PINGING, /* Ping in process */ + RXRPC_CALL_RETRANS_TIMEOUT, /* Retransmission due to timeout occurred */ }; /* @@ -447,6 +448,17 @@ enum rxrpc_call_completion { }; /* + * Call Tx congestion management modes. + */ +enum rxrpc_congest_mode { + RXRPC_CALL_SLOW_START, + RXRPC_CALL_CONGEST_AVOIDANCE, + RXRPC_CALL_PACKET_LOSS, + RXRPC_CALL_FAST_RETRANSMIT, + NR__RXRPC_CONGEST_MODES +}; + +/* * RxRPC call definition * - matched by { connection, call_id } */ @@ -518,6 +530,20 @@ struct rxrpc_call { * not hard-ACK'd packet follows this. */ rxrpc_seq_t tx_top; /* Highest Tx slot allocated. */ + + /* TCP-style slow-start congestion control [RFC5681]. Since the SMSS + * is fixed, we keep these numbers in terms of segments (ie. DATA + * packets) rather than bytes. + */ +#define RXRPC_TX_SMSS RXRPC_JUMBO_DATALEN + u8 cong_cwnd; /* Congestion window size */ + u8 cong_extra; /* Extra to send for congestion management */ + u8 cong_ssthresh; /* Slow-start threshold */ + enum rxrpc_congest_mode cong_mode:8; /* Congestion management mode */ + u8 cong_dup_acks; /* Count of ACKs showing missing packets */ + u8 cong_cumul_acks; /* Cumulative ACK count */ + ktime_t cong_tstamp; /* Last time cwnd was changed */ + rxrpc_seq_t rx_hard_ack; /* Dead slot in buffer; the first received but not * consumed packet follows this. */ @@ -533,11 +559,36 @@ struct rxrpc_call { u16 ackr_skew; /* skew on packet being ACK'd */ rxrpc_serial_t ackr_serial; /* serial of packet being ACK'd */ rxrpc_seq_t ackr_prev_seq; /* previous sequence number received */ + rxrpc_seq_t ackr_consumed; /* Highest packet shown consumed */ + rxrpc_seq_t ackr_seen; /* Highest packet shown seen */ rxrpc_serial_t ackr_ping; /* Last ping sent */ ktime_t ackr_ping_time; /* Time last ping sent */ /* transmission-phase ACK management */ + ktime_t acks_latest_ts; /* Timestamp of latest ACK received */ rxrpc_serial_t acks_latest; /* serial number of latest ACK received */ + rxrpc_seq_t acks_lowest_nak; /* Lowest NACK in the buffer (or ==tx_hard_ack) */ +}; + +/* + * Summary of a new ACK and the changes it made to the Tx buffer packet states. + */ +struct rxrpc_ack_summary { + u8 ack_reason; + u8 nr_acks; /* Number of ACKs in packet */ + u8 nr_nacks; /* Number of NACKs in packet */ + u8 nr_new_acks; /* Number of new ACKs in packet */ + u8 nr_new_nacks; /* Number of new NACKs in packet */ + u8 nr_rot_new_acks; /* Number of rotated new ACKs */ + bool new_low_nack; /* T if new low NACK found */ + bool retrans_timeo; /* T if reTx due to timeout happened */ + u8 flight_size; /* Number of unreceived transmissions */ + /* Place to stash values for tracing */ + enum rxrpc_congest_mode mode:8; + u8 cwnd; + u8 ssthresh; + u8 dup_acks; + u8 cumulative_acks; }; enum rxrpc_skb_trace { @@ -680,6 +731,7 @@ extern const char rxrpc_rtt_rx_traces[rxrpc_rtt_rx__nr_trace][5]; enum rxrpc_timer_trace { rxrpc_timer_begin, + rxrpc_timer_init_for_reply, rxrpc_timer_expired, rxrpc_timer_set_for_ack, rxrpc_timer_set_for_resend, @@ -690,11 +742,15 @@ enum rxrpc_timer_trace { extern const char rxrpc_timer_traces[rxrpc_timer__nr_trace][8]; enum rxrpc_propose_ack_trace { + rxrpc_propose_ack_client_tx_end, rxrpc_propose_ack_input_data, + rxrpc_propose_ack_ping_for_lost_ack, + rxrpc_propose_ack_ping_for_lost_reply, rxrpc_propose_ack_ping_for_params, rxrpc_propose_ack_respond_to_ack, rxrpc_propose_ack_respond_to_ping, rxrpc_propose_ack_retry_tx, + rxrpc_propose_ack_rotate_rx, rxrpc_propose_ack_terminal_ack, rxrpc_propose_ack__nr_trace }; @@ -709,6 +765,21 @@ enum rxrpc_propose_ack_outcome { extern const char rxrpc_propose_ack_traces[rxrpc_propose_ack__nr_trace][8]; extern const char *const rxrpc_propose_ack_outcomes[rxrpc_propose_ack__nr_outcomes]; +enum rxrpc_congest_change { + rxrpc_cong_begin_retransmission, + rxrpc_cong_cleared_nacks, + rxrpc_cong_new_low_nack, + rxrpc_cong_no_change, + rxrpc_cong_progress, + rxrpc_cong_retransmit_again, + rxrpc_cong_rtt_window_end, + rxrpc_cong_saw_nack, + rxrpc_congest__nr_change +}; + +extern const char rxrpc_congest_modes[NR__RXRPC_CONGEST_MODES][10]; +extern const char rxrpc_congest_changes[rxrpc_congest__nr_change][9]; + extern const char *const rxrpc_pkts[]; extern const char const rxrpc_ack_names[RXRPC_ACK__INVALID + 1][4]; diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index a78a92fe5d77..0e8478012212 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -100,6 +100,7 @@ static void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason, expiry = rxrpc_soft_ack_delay; break; + case RXRPC_ACK_PING: case RXRPC_ACK_IDLE: if (rxrpc_idle_ack_delay < expiry) expiry = rxrpc_idle_ack_delay; @@ -146,6 +147,14 @@ void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason, } /* + * Handle congestion being detected by the retransmit timeout. + */ +static void rxrpc_congestion_timeout(struct rxrpc_call *call) +{ + set_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags); +} + +/* * Perform retransmission of NAK'd and unack'd packets. */ static void rxrpc_resend(struct rxrpc_call *call) @@ -153,9 +162,9 @@ static void rxrpc_resend(struct rxrpc_call *call) struct rxrpc_skb_priv *sp; struct sk_buff *skb; rxrpc_seq_t cursor, seq, top; - ktime_t now = ktime_get_real(), max_age, oldest, resend_at; + ktime_t now = ktime_get_real(), max_age, oldest, resend_at, ack_ts; int ix; - u8 annotation, anno_type; + u8 annotation, anno_type, retrans = 0, unacked = 0; _enter("{%d,%d}", call->tx_hard_ack, call->tx_top); @@ -192,16 +201,44 @@ static void rxrpc_resend(struct rxrpc_call *call) oldest = skb->tstamp; continue; } + if (!(annotation & RXRPC_TX_ANNO_RESENT)) + unacked++; } /* Okay, we need to retransmit a packet. */ call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS | annotation; + retrans++; trace_rxrpc_retransmit(call, seq, annotation | anno_type, ktime_to_ns(ktime_sub(skb->tstamp, max_age))); } - resend_at = ktime_sub(ktime_add_ms(oldest, rxrpc_resend_timeout), now); - call->resend_at = jiffies + nsecs_to_jiffies(ktime_to_ns(resend_at)); + resend_at = ktime_add_ms(oldest, rxrpc_resend_timeout); + call->resend_at = jiffies + + nsecs_to_jiffies(ktime_to_ns(ktime_sub(resend_at, now))) + + 1; /* We have to make sure that the calculated jiffies value + * falls at or after the nsec value, or we shall loop + * ceaselessly because the timer times out, but we haven't + * reached the nsec timeout yet. + */ + + if (unacked) + rxrpc_congestion_timeout(call); + + /* If there was nothing that needed retransmission then it's likely + * that an ACK got lost somewhere. Send a ping to find out instead of + * retransmitting data. + */ + if (!retrans) { + rxrpc_set_timer(call, rxrpc_timer_set_for_resend); + spin_unlock_bh(&call->lock); + ack_ts = ktime_sub(now, call->acks_latest_ts); + if (ktime_to_ns(ack_ts) < call->peer->rtt) + goto out; + rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, false, + rxrpc_propose_ack_ping_for_lost_ack); + rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK); + goto out; + } /* Now go through the Tx window and perform the retransmissions. We * have to drop the lock for each send. If an ACK comes in whilst the @@ -253,6 +290,7 @@ static void rxrpc_resend(struct rxrpc_call *call) out_unlock: spin_unlock_bh(&call->lock); +out: _leave(""); } @@ -286,6 +324,7 @@ recheck_state: if (time_after_eq(now, call->expire_at)) { rxrpc_abort_call("EXP", call, 0, RX_CALL_TIMEOUT, ETIME); set_bit(RXRPC_CALL_EV_ABORT, &call->events); + goto recheck_state; } if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events) || diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c index a53f4c2c0025..d4b3293b78fa 100644 --- a/net/rxrpc/call_object.c +++ b/net/rxrpc/call_object.c @@ -160,6 +160,14 @@ struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp) call->rx_winsize = rxrpc_rx_window_size; call->tx_winsize = 16; call->rx_expect_next = 1; + + if (RXRPC_TX_SMSS > 2190) + call->cong_cwnd = 2; + else if (RXRPC_TX_SMSS > 1095) + call->cong_cwnd = 3; + else + call->cong_cwnd = 4; + call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1; return call; nomem_2: @@ -176,6 +184,7 @@ static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx, gfp_t gfp) { struct rxrpc_call *call; + ktime_t now; _enter(""); @@ -185,6 +194,9 @@ static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx, call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; call->service_id = srx->srx_service; call->tx_phase = true; + now = ktime_get_real(); + call->acks_latest_ts = now; + call->cong_tstamp = now; _leave(" = %p", call); return call; @@ -325,6 +337,7 @@ void rxrpc_incoming_call(struct rxrpc_sock *rx, call->state = RXRPC_CALL_SERVER_ACCEPTING; if (sp->hdr.securityIndex > 0) call->state = RXRPC_CALL_SERVER_SECURING; + call->cong_tstamp = skb->tstamp; /* Set the channel for this call. We don't get channel_lock as we're * only defending against the data_ready handler (which we're called diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c index a1cf1ec5f29e..37609ce89f52 100644 --- a/net/rxrpc/conn_event.c +++ b/net/rxrpc/conn_event.c @@ -97,6 +97,7 @@ static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn, pkt.info.maxMTU = htonl(mtu); pkt.info.rwind = htonl(rxrpc_rx_window_size); pkt.info.jumbo_max = htonl(rxrpc_rx_jumbo_max); + pkt.whdr.flags |= RXRPC_SLOW_START_OK; len += sizeof(pkt.ack) + sizeof(pkt.info); break; } diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index 349698d87ad1..094720dd1eaf 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -37,6 +37,166 @@ static void rxrpc_proto_abort(const char *why, } /* + * Do TCP-style congestion management [RFC 5681]. + */ +static void rxrpc_congestion_management(struct rxrpc_call *call, + struct sk_buff *skb, + struct rxrpc_ack_summary *summary) +{ + enum rxrpc_congest_change change = rxrpc_cong_no_change; + struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + unsigned int cumulative_acks = call->cong_cumul_acks; + unsigned int cwnd = call->cong_cwnd; + bool resend = false; + + summary->flight_size = + (call->tx_top - call->tx_hard_ack) - summary->nr_acks; + + if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) { + summary->retrans_timeo = true; + call->cong_ssthresh = max_t(unsigned int, + summary->flight_size / 2, 2); + cwnd = 1; + if (cwnd > call->cong_ssthresh && + call->cong_mode == RXRPC_CALL_SLOW_START) { + call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; + call->cong_tstamp = skb->tstamp; + cumulative_acks = 0; + } + } + + cumulative_acks += summary->nr_new_acks; + cumulative_acks += summary->nr_rot_new_acks; + if (cumulative_acks > 255) + cumulative_acks = 255; + + summary->mode = call->cong_mode; + summary->cwnd = call->cong_cwnd; + summary->ssthresh = call->cong_ssthresh; + summary->cumulative_acks = cumulative_acks; + summary->dup_acks = call->cong_dup_acks; + + switch (call->cong_mode) { + case RXRPC_CALL_SLOW_START: + if (summary->nr_nacks > 0) + goto packet_loss_detected; + if (summary->cumulative_acks > 0) + cwnd += 1; + if (cwnd > call->cong_ssthresh) { + call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; + call->cong_tstamp = skb->tstamp; + } + goto out; + + case RXRPC_CALL_CONGEST_AVOIDANCE: + if (summary->nr_nacks > 0) + goto packet_loss_detected; + + /* We analyse the number of packets that get ACK'd per RTT + * period and increase the window if we managed to fill it. + */ + if (call->peer->rtt_usage == 0) + goto out; + if (ktime_before(skb->tstamp, + ktime_add_ns(call->cong_tstamp, + call->peer->rtt))) + goto out_no_clear_ca; + change = rxrpc_cong_rtt_window_end; + call->cong_tstamp = skb->tstamp; + if (cumulative_acks >= cwnd) + cwnd++; + goto out; + + case RXRPC_CALL_PACKET_LOSS: + if (summary->nr_nacks == 0) + goto resume_normality; + + if (summary->new_low_nack) { + change = rxrpc_cong_new_low_nack; + call->cong_dup_acks = 1; + if (call->cong_extra > 1) + call->cong_extra = 1; + goto send_extra_data; + } + + call->cong_dup_acks++; + if (call->cong_dup_acks < 3) + goto send_extra_data; + + change = rxrpc_cong_begin_retransmission; + call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT; + call->cong_ssthresh = max_t(unsigned int, + summary->flight_size / 2, 2); + cwnd = call->cong_ssthresh + 3; + call->cong_extra = 0; + call->cong_dup_acks = 0; + resend = true; + goto out; + + case RXRPC_CALL_FAST_RETRANSMIT: + if (!summary->new_low_nack) { + if (summary->nr_new_acks == 0) + cwnd += 1; + call->cong_dup_acks++; + if (call->cong_dup_acks == 2) { + change = rxrpc_cong_retransmit_again; + call->cong_dup_acks = 0; + resend = true; + } + } else { + change = rxrpc_cong_progress; + cwnd = call->cong_ssthresh; + if (summary->nr_nacks == 0) + goto resume_normality; + } + goto out; + + default: + BUG(); + goto out; + } + +resume_normality: + change = rxrpc_cong_cleared_nacks; + call->cong_dup_acks = 0; + call->cong_extra = 0; + call->cong_tstamp = skb->tstamp; + if (cwnd <= call->cong_ssthresh) + call->cong_mode = RXRPC_CALL_SLOW_START; + else + call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; +out: + cumulative_acks = 0; +out_no_clear_ca: + if (cwnd >= RXRPC_RXTX_BUFF_SIZE - 1) + cwnd = RXRPC_RXTX_BUFF_SIZE - 1; + call->cong_cwnd = cwnd; + call->cong_cumul_acks = cumulative_acks; + trace_rxrpc_congest(call, summary, sp->hdr.serial, change); + if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) + rxrpc_queue_call(call); + return; + +packet_loss_detected: + change = rxrpc_cong_saw_nack; + call->cong_mode = RXRPC_CALL_PACKET_LOSS; + call->cong_dup_acks = 0; + goto send_extra_data; + +send_extra_data: + /* Send some previously unsent DATA if we have some to advance the ACK + * state. + */ + if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & + RXRPC_TX_ANNO_LAST || + summary->nr_acks != call->tx_top - call->tx_hard_ack) { + call->cong_extra++; + wake_up(&call->waitq); + } + goto out_no_clear_ca; +} + +/* * Ping the other end to fill our RTT cache and to retrieve the rwind * and MTU parameters. */ @@ -56,12 +216,20 @@ static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb, /* * Apply a hard ACK by advancing the Tx window. */ -static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to) +static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to, + struct rxrpc_ack_summary *summary) { struct sk_buff *skb, *list = NULL; int ix; u8 annotation; + if (call->acks_lowest_nak == call->tx_hard_ack) { + call->acks_lowest_nak = to; + } else if (before_eq(call->acks_lowest_nak, to)) { + summary->new_low_nack = true; + call->acks_lowest_nak = to; + } + spin_lock(&call->lock); while (before(call->tx_hard_ack, to)) { @@ -77,6 +245,8 @@ static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to) if (annotation & RXRPC_TX_ANNO_LAST) set_bit(RXRPC_CALL_TX_LAST, &call->flags); + if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) + summary->nr_rot_new_acks++; } spin_unlock(&call->lock); @@ -128,6 +298,8 @@ static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun, write_unlock(&call->state_lock); if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) { + rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, 0, false, true, + rxrpc_propose_ack_client_tx_end); trace_rxrpc_transmit(call, rxrpc_transmit_await_reply); } else { trace_rxrpc_transmit(call, rxrpc_transmit_end); @@ -147,10 +319,20 @@ bad_state: */ static bool rxrpc_receiving_reply(struct rxrpc_call *call) { + struct rxrpc_ack_summary summary = { 0 }; rxrpc_seq_t top = READ_ONCE(call->tx_top); + if (call->ackr_reason) { + spin_lock_bh(&call->lock); + call->ackr_reason = 0; + call->resend_at = call->expire_at; + call->ack_at = call->expire_at; + spin_unlock_bh(&call->lock); + rxrpc_set_timer(call, rxrpc_timer_init_for_reply); + } + if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) - rxrpc_rotate_tx_window(call, top); + rxrpc_rotate_tx_window(call, top, &summary); if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { rxrpc_proto_abort("TXL", call, top); return false; @@ -331,8 +513,16 @@ next_subpacket: call->rxtx_annotations[ix] = annotation; smp_wmb(); call->rxtx_buffer[ix] = skb; - if (after(seq, call->rx_top)) + if (after(seq, call->rx_top)) { smp_store_release(&call->rx_top, seq); + } else if (before(seq, call->rx_top)) { + /* Send an immediate ACK if we fill in a hole */ + if (!ack) { + ack = RXRPC_ACK_DELAY; + ack_serial = serial; + } + immediate_ack = true; + } if (flags & RXRPC_LAST_PACKET) { set_bit(RXRPC_CALL_RX_LAST, &call->flags); trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); @@ -491,9 +681,9 @@ static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb, * the time the ACK was sent. */ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, - rxrpc_seq_t seq, int nr_acks) + rxrpc_seq_t seq, int nr_acks, + struct rxrpc_ack_summary *summary) { - bool resend = false; int ix; u8 annotation, anno_type; @@ -504,28 +694,32 @@ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, annotation &= ~RXRPC_TX_ANNO_MASK; switch (*acks++) { case RXRPC_ACK_TYPE_ACK: + summary->nr_acks++; if (anno_type == RXRPC_TX_ANNO_ACK) continue; + summary->nr_new_acks++; call->rxtx_annotations[ix] = RXRPC_TX_ANNO_ACK | annotation; break; case RXRPC_ACK_TYPE_NACK: + if (!summary->nr_nacks && + call->acks_lowest_nak != seq) { + call->acks_lowest_nak = seq; + summary->new_low_nack = true; + } + summary->nr_nacks++; if (anno_type == RXRPC_TX_ANNO_NAK) continue; + summary->nr_new_nacks++; if (anno_type == RXRPC_TX_ANNO_RETRANS) continue; call->rxtx_annotations[ix] = RXRPC_TX_ANNO_NAK | annotation; - resend = true; break; default: return rxrpc_proto_abort("SFT", call, 0); } } - - if (resend && - !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) - rxrpc_queue_call(call); } /* @@ -541,7 +735,7 @@ static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks, static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, u16 skew) { - u8 ack_reason; + struct rxrpc_ack_summary summary = { 0 }; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); union { struct rxrpc_ackpacket ack; @@ -564,10 +758,10 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, first_soft_ack = ntohl(buf.ack.firstPacket); hard_ack = first_soft_ack - 1; nr_acks = buf.ack.nAcks; - ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? - buf.ack.reason : RXRPC_ACK__INVALID); + summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? + buf.ack.reason : RXRPC_ACK__INVALID); - trace_rxrpc_rx_ack(call, first_soft_ack, ack_reason, nr_acks); + trace_rxrpc_rx_ack(call, first_soft_ack, summary.ack_reason, nr_acks); _proto("Rx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }", sp->hdr.serial, @@ -575,7 +769,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, first_soft_ack, ntohl(buf.ack.previousPacket), acked_serial, - rxrpc_ack_names[ack_reason], + rxrpc_ack_names[summary.ack_reason], buf.ack.nAcks); if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE) @@ -623,6 +817,7 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, sp->hdr.serial, call->acks_latest); return; } + call->acks_latest_ts = skb->tstamp; call->acks_latest = sp->hdr.serial; if (before(hard_ack, call->tx_hard_ack) || @@ -632,12 +827,13 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, return rxrpc_proto_abort("AKN", call, 0); if (after(hard_ack, call->tx_hard_ack)) - rxrpc_rotate_tx_window(call, hard_ack); + rxrpc_rotate_tx_window(call, hard_ack, &summary); if (nr_acks > 0) { if (skb_copy_bits(skb, sp->offset, buf.acks, nr_acks) < 0) return rxrpc_proto_abort("XSA", call, 0); - rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks); + rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, + &summary); } if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) { @@ -645,6 +841,14 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, return; } + if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & + RXRPC_TX_ANNO_LAST && + summary.nr_acks == call->tx_top - hard_ack) + rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial, + false, true, + rxrpc_propose_ack_ping_for_lost_reply); + + return rxrpc_congestion_management(call, skb, &summary); } /* @@ -652,11 +856,12 @@ static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb, */ static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb) { + struct rxrpc_ack_summary summary = { 0 }; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); _proto("Rx ACKALL %%%u", sp->hdr.serial); - rxrpc_rotate_tx_window(call, call->tx_top); + rxrpc_rotate_tx_window(call, call->tx_top, &summary); if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) rxrpc_end_tx_phase(call, false, "ETL"); } diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c index 1ca14835d87f..aedb8978226d 100644 --- a/net/rxrpc/misc.c +++ b/net/rxrpc/misc.c @@ -191,17 +191,22 @@ const char rxrpc_rtt_rx_traces[rxrpc_rtt_rx__nr_trace][5] = { const char rxrpc_timer_traces[rxrpc_timer__nr_trace][8] = { [rxrpc_timer_begin] = "Begin ", [rxrpc_timer_expired] = "*EXPR*", + [rxrpc_timer_init_for_reply] = "IniRpl", [rxrpc_timer_set_for_ack] = "SetAck", [rxrpc_timer_set_for_send] = "SetTx ", [rxrpc_timer_set_for_resend] = "SetRTx", }; const char rxrpc_propose_ack_traces[rxrpc_propose_ack__nr_trace][8] = { + [rxrpc_propose_ack_client_tx_end] = "ClTxEnd", [rxrpc_propose_ack_input_data] = "DataIn ", + [rxrpc_propose_ack_ping_for_lost_ack] = "LostAck", + [rxrpc_propose_ack_ping_for_lost_reply] = "LostRpl", [rxrpc_propose_ack_ping_for_params] = "Params ", [rxrpc_propose_ack_respond_to_ack] = "Rsp2Ack", [rxrpc_propose_ack_respond_to_ping] = "Rsp2Png", [rxrpc_propose_ack_retry_tx] = "RetryTx", + [rxrpc_propose_ack_rotate_rx] = "RxAck ", [rxrpc_propose_ack_terminal_ack] = "ClTerm ", }; @@ -210,3 +215,21 @@ const char *const rxrpc_propose_ack_outcomes[rxrpc_propose_ack__nr_outcomes] = { [rxrpc_propose_ack_update] = " Update", [rxrpc_propose_ack_subsume] = " Subsume", }; + +const char rxrpc_congest_modes[NR__RXRPC_CONGEST_MODES][10] = { + [RXRPC_CALL_SLOW_START] = "SlowStart", + [RXRPC_CALL_CONGEST_AVOIDANCE] = "CongAvoid", + [RXRPC_CALL_PACKET_LOSS] = "PktLoss ", + [RXRPC_CALL_FAST_RETRANSMIT] = "FastReTx ", +}; + +const char rxrpc_congest_changes[rxrpc_congest__nr_change][9] = { + [rxrpc_cong_begin_retransmission] = " Retrans", + [rxrpc_cong_cleared_nacks] = " Cleared", + [rxrpc_cong_new_low_nack] = " NewLowN", + [rxrpc_cong_no_change] = "", + [rxrpc_cong_progress] = " Progres", + [rxrpc_cong_retransmit_again] = " ReTxAgn", + [rxrpc_cong_rtt_window_end] = " RttWinE", + [rxrpc_cong_saw_nack] = " SawNack", +}; diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index 0c563e325c9d..cf43a715685e 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -36,7 +36,9 @@ struct rxrpc_pkt_buffer { * Fill out an ACK packet. */ static size_t rxrpc_fill_out_ack(struct rxrpc_call *call, - struct rxrpc_pkt_buffer *pkt) + struct rxrpc_pkt_buffer *pkt, + rxrpc_seq_t *_hard_ack, + rxrpc_seq_t *_top) { rxrpc_serial_t serial; rxrpc_seq_t hard_ack, top, seq; @@ -48,6 +50,8 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_call *call, serial = call->ackr_serial; hard_ack = READ_ONCE(call->rx_hard_ack); top = smp_load_acquire(&call->rx_top); + *_hard_ack = hard_ack; + *_top = top; pkt->ack.bufferSpace = htons(8); pkt->ack.maxSkew = htons(call->ackr_skew); @@ -96,6 +100,7 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type) struct msghdr msg; struct kvec iov[2]; rxrpc_serial_t serial; + rxrpc_seq_t hard_ack, top; size_t len, n; bool ping = false; int ioc, ret; @@ -146,12 +151,14 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type) goto out; } ping = (call->ackr_reason == RXRPC_ACK_PING); - n = rxrpc_fill_out_ack(call, pkt); + n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top); call->ackr_reason = 0; spin_unlock_bh(&call->lock); + pkt->whdr.flags |= RXRPC_SLOW_START_OK; + iov[0].iov_len += sizeof(pkt->ack) + n; iov[1].iov_base = &pkt->ackinfo; iov[1].iov_len = sizeof(pkt->ackinfo); @@ -203,18 +210,22 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type) if (ping) call->ackr_ping_time = ktime_get_real(); - if (ret < 0 && call->state < RXRPC_CALL_COMPLETE) { - switch (type) { - case RXRPC_PACKET_TYPE_ACK: + if (type == RXRPC_PACKET_TYPE_ACK && + call->state < RXRPC_CALL_COMPLETE) { + if (ret < 0) { clear_bit(RXRPC_CALL_PINGING, &call->flags); rxrpc_propose_ACK(call, pkt->ack.reason, ntohs(pkt->ack.maxSkew), ntohl(pkt->ack.serial), true, true, rxrpc_propose_ack_retry_tx); - break; - case RXRPC_PACKET_TYPE_ABORT: - break; + } else { + spin_lock_bh(&call->lock); + if (after(hard_ack, call->ackr_consumed)) + call->ackr_consumed = hard_ack; + if (after(top, call->ackr_seen)) + call->ackr_seen = top; + spin_unlock_bh(&call->lock); } } @@ -267,8 +278,11 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb) msg.msg_controllen = 0; msg.msg_flags = 0; - /* If our RTT cache needs working on, request an ACK. */ - if ((call->peer->rtt_usage < 3 && sp->hdr.seq & 1) || + /* If our RTT cache needs working on, request an ACK. Also request + * ACKs if a DATA packet appears to have been lost. + */ + if (call->cong_mode == RXRPC_CALL_FAST_RETRANSMIT || + (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) || ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), ktime_get_real())) whdr.flags |= RXRPC_REQUEST_ACK; diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c index 8c7f3de45bac..038ae62ddb4d 100644 --- a/net/rxrpc/recvmsg.c +++ b/net/rxrpc/recvmsg.c @@ -133,7 +133,7 @@ static int rxrpc_recvmsg_new_call(struct rxrpc_sock *rx, /* * End the packet reception phase. */ -static void rxrpc_end_rx_phase(struct rxrpc_call *call) +static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial) { _enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]); @@ -141,7 +141,7 @@ static void rxrpc_end_rx_phase(struct rxrpc_call *call) ASSERTCMP(call->rx_hard_ack, ==, call->rx_top); if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) { - rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, 0, true, false, + rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, serial, true, false, rxrpc_propose_ack_terminal_ack); rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK); } @@ -201,8 +201,19 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call) _debug("%u,%u,%02x", hard_ack, top, flags); trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack); - if (flags & RXRPC_LAST_PACKET) - rxrpc_end_rx_phase(call); + if (flags & RXRPC_LAST_PACKET) { + rxrpc_end_rx_phase(call, serial); + } else { + /* Check to see if there's an ACK that needs sending. */ + if (after_eq(hard_ack, call->ackr_consumed + 2) || + after_eq(top, call->ackr_seen + 2) || + (hard_ack == top && after(hard_ack, call->ackr_consumed))) + rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 0, serial, + true, false, + rxrpc_propose_ack_rotate_rx); + if (call->ackr_reason) + rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK); + } } /* diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c index 99939372b5a4..1f8040d82395 100644 --- a/net/rxrpc/sendmsg.c +++ b/net/rxrpc/sendmsg.c @@ -45,7 +45,9 @@ static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx, for (;;) { set_current_state(TASK_INTERRUPTIBLE); ret = 0; - if (call->tx_top - call->tx_hard_ack < call->tx_winsize) + if (call->tx_top - call->tx_hard_ack < + min_t(unsigned int, call->tx_winsize, + call->cong_cwnd + call->cong_extra)) break; if (call->state >= RXRPC_CALL_COMPLETE) { ret = -call->error; @@ -203,7 +205,8 @@ static int rxrpc_send_data(struct rxrpc_sock *rx, _debug("alloc"); if (call->tx_top - call->tx_hard_ack >= - call->tx_winsize) { + min_t(unsigned int, call->tx_winsize, + call->cong_cwnd + call->cong_extra)) { ret = -EAGAIN; if (msg->msg_flags & MSG_DONTWAIT) goto maybe_error; |