From 805b21b929e29192fb5de16154f616bfc1116e3e Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 24 Sep 2016 18:05:26 +0100 Subject: [PATCH] rxrpc: Send an ACK after every few DATA packets we receive Send an ACK if we haven't sent one for the last two packets we've received. This keeps the other end apprised of where we've got to - which is important if they're doing slow-start. We do this in recvmsg so that we can dispatch a packet directly without the need to wake up the background thread. This should possibly be made configurable in future. Signed-off-by: David Howells --- net/rxrpc/ar-internal.h | 3 +++ net/rxrpc/misc.c | 1 + net/rxrpc/output.c | 25 +++++++++++++++++-------- net/rxrpc/recvmsg.c | 13 ++++++++++++- 4 files changed, 33 insertions(+), 9 deletions(-) diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 042dbcc..e3bf9c0 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -533,6 +533,8 @@ 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 */ @@ -695,6 +697,7 @@ enum rxrpc_propose_ack_trace { 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 }; diff --git a/net/rxrpc/misc.c b/net/rxrpc/misc.c index 1ca1483..a473fd7 100644 --- a/net/rxrpc/misc.c +++ b/net/rxrpc/misc.c @@ -202,6 +202,7 @@ const char rxrpc_propose_ack_traces[rxrpc_propose_ack__nr_trace][8] = { [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 ", }; diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index 0c563e3..3eb0144 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; @@ -146,7 +151,7 @@ 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); @@ -203,18 +208,22 @@ 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); } } diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c index 8c7f3de..a7458c3 100644 --- a/net/rxrpc/recvmsg.c +++ b/net/rxrpc/recvmsg.c @@ -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) + if (flags & RXRPC_LAST_PACKET) { rxrpc_end_rx_phase(call); + } 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); + } } /* -- 2.7.4