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 <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
This commit is contained in:
David Howells 2022-10-17 10:55:41 +01:00
parent af094824f2
commit 84e28aa513
3 changed files with 19 additions and 6 deletions

View File

@ -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") \

View File

@ -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)) {

View File

@ -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)) {