From 84e28aa513af814807a5e9a0e5f3cab773946f3c Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 17 Oct 2022 10:55:41 +0100 Subject: [PATCH] rxrpc: Generate extra pings for RTT during heavy-receive call When doing a call that has a single transmitted data packet and a massive amount of received data packets, we only ping for one RTT sample, which means we don't get a good reading on it. Fix this by converting occasional IDLE ACKs into PING ACKs to elicit a response. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- include/trace/events/rxrpc.h | 3 ++- net/rxrpc/call_event.c | 15 ++++++++++++--- net/rxrpc/output.c | 7 +++++-- 3 files changed, 19 insertions(+), 6 deletions(-) diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index cdcadb1..450b8f3 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -360,11 +360,12 @@ EM(rxrpc_propose_ack_client_tx_end, "ClTxEnd") \ EM(rxrpc_propose_ack_input_data, "DataIn ") \ EM(rxrpc_propose_ack_input_data_hole, "DataInH") \ - EM(rxrpc_propose_ack_ping_for_check_life, "ChkLife") \ EM(rxrpc_propose_ack_ping_for_keepalive, "KeepAlv") \ EM(rxrpc_propose_ack_ping_for_lost_ack, "LostAck") \ EM(rxrpc_propose_ack_ping_for_lost_reply, "LostRpl") \ + EM(rxrpc_propose_ack_ping_for_old_rtt, "OldRtt ") \ EM(rxrpc_propose_ack_ping_for_params, "Params ") \ + EM(rxrpc_propose_ack_ping_for_rtt, "Rtt ") \ EM(rxrpc_propose_ack_processing_op, "ProcOp ") \ EM(rxrpc_propose_ack_respond_to_ack, "Rsp2Ack") \ EM(rxrpc_propose_ack_respond_to_ping, "Rsp2Png") \ diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index 1abdef1..cf9799b 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -498,9 +498,18 @@ bool rxrpc_input_call_event(struct rxrpc_call *call, struct sk_buff *skb) rxrpc_send_ACK(call, RXRPC_ACK_IDLE, 0, rxrpc_propose_ack_rx_idle); - if (atomic_read(&call->ackr_nr_unacked) > 2) - rxrpc_send_ACK(call, RXRPC_ACK_IDLE, 0, - rxrpc_propose_ack_input_data); + if (atomic_read(&call->ackr_nr_unacked) > 2) { + if (call->peer->rtt_count < 3) + rxrpc_send_ACK(call, RXRPC_ACK_PING, 0, + rxrpc_propose_ack_ping_for_rtt); + else if (ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), + ktime_get_real())) + rxrpc_send_ACK(call, RXRPC_ACK_PING, 0, + rxrpc_propose_ack_ping_for_old_rtt); + else + rxrpc_send_ACK(call, RXRPC_ACK_IDLE, 0, + rxrpc_propose_ack_input_data); + } /* Make sure the timer is restarted */ if (!__rxrpc_call_is_complete(call)) { diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index a9746be..98b5d0d 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -253,12 +253,15 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, struct rxrpc_txbuf *txb) iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len); ret = do_udp_sendmsg(conn->local->socket, &msg, len); call->peer->last_tx_at = ktime_get_seconds(); - if (ret < 0) + if (ret < 0) { trace_rxrpc_tx_fail(call->debug_id, serial, ret, rxrpc_tx_point_call_ack); - else + } else { trace_rxrpc_tx_packet(call->debug_id, &txb->wire, rxrpc_tx_point_call_ack); + if (txb->wire.flags & RXRPC_REQUEST_ACK) + call->peer->rtt_last_req = ktime_get_real(); + } rxrpc_tx_backoff(call, ret); if (!__rxrpc_call_is_complete(call)) { -- 2.7.4