From 4d843be56ba6a8c0e566afd58775742d9e721505 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 5 Apr 2022 21:48:48 +0100 Subject: rxrpc: Trace setting of the request-ack flag Add a tracepoint to log why the request-ack flag is set on an outgoing DATA packet, allowing debugging as to why. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- net/rxrpc/output.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) (limited to 'net/rxrpc/output.c') diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index 9683617db704..2922c10bd500 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -350,6 +350,7 @@ int rxrpc_send_abort_packet(struct rxrpc_call *call) int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb, bool retrans) { + enum rxrpc_req_ack_trace why; struct rxrpc_connection *conn = call->conn; struct rxrpc_wire_header whdr; struct rxrpc_skb_priv *sp = rxrpc_skb(skb); @@ -405,16 +406,29 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb, * service call, lest OpenAFS incorrectly send us an ACK with some * soft-ACKs in it and then never follow up with a proper hard ACK. */ - if ((!(sp->hdr.flags & RXRPC_LAST_PACKET) || - rxrpc_to_server(sp) - ) && - (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) || - retrans || - call->cong_mode == RXRPC_CALL_SLOW_START || - (call->peer->rtt_count < 3 && sp->hdr.seq & 1) || - ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), - ktime_get_real()))) + if (whdr.flags & RXRPC_REQUEST_ACK) + why = rxrpc_reqack_already_on; + else if ((whdr.flags & RXRPC_LAST_PACKET) && rxrpc_to_client(sp)) + why = rxrpc_reqack_no_srv_last; + else if (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events)) + why = rxrpc_reqack_ack_lost; + else if (retrans) + why = rxrpc_reqack_retrans; + else if (call->cong_mode == RXRPC_CALL_SLOW_START && call->cong_cwnd <= 2) + why = rxrpc_reqack_slow_start; + else if (call->tx_winsize <= 2) + why = rxrpc_reqack_small_txwin; + else if (call->peer->rtt_count < 3 && sp->hdr.seq & 1) + why = rxrpc_reqack_more_rtt; + else if (ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), ktime_get_real())) + why = rxrpc_reqack_old_rtt; + else + goto dont_set_request_ack; + + trace_rxrpc_req_ack(call->debug_id, sp->hdr.seq, why); + if (why != rxrpc_reqack_no_srv_last) whdr.flags |= RXRPC_REQUEST_ACK; +dont_set_request_ack: if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) { static int lose; -- cgit v1.2.3