From 32cf8edb079a6a687a2b5dba39a813a0bbd0ddf9 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 11 Nov 2022 13:47:35 +0000 Subject: rxrpc: Trace/count transmission underflows and cwnd resets Add a tracepoint to log when a cwnd reset occurs due to lack of transmission on a call. Add stat counters to count transmission underflows (ie. when we have tx window space, but sendmsg doesn't manage to keep up), cwnd resets and transmission failures. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- net/rxrpc/ar-internal.h | 3 +++ net/rxrpc/call_event.c | 4 +++- net/rxrpc/input.c | 7 +++++-- net/rxrpc/output.c | 2 ++ net/rxrpc/proc.c | 14 ++++++++++---- 5 files changed, 23 insertions(+), 7 deletions(-) (limited to 'net/rxrpc') diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 6b993a3d4186..6cfe366ee224 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -101,6 +101,9 @@ struct rxrpc_net { atomic_t stat_tx_data_retrans; atomic_t stat_tx_data_send; atomic_t stat_tx_data_send_frag; + atomic_t stat_tx_data_send_fail; + atomic_t stat_tx_data_underflow; + atomic_t stat_tx_data_cwnd_reset; atomic_t stat_rx_data; atomic_t stat_rx_data_reqack; atomic_t stat_rx_data_jumbo; diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index 18591f9ecc6a..9f1e490ab976 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -317,8 +317,10 @@ static void rxrpc_transmit_some_data(struct rxrpc_call *call) case RXRPC_CALL_CLIENT_AWAIT_REPLY: if (!rxrpc_tx_window_has_space(call)) return; - if (list_empty(&call->tx_sendmsg)) + if (list_empty(&call->tx_sendmsg)) { + rxrpc_inc_stat(call->rxnet, stat_tx_data_underflow); return; + } rxrpc_decant_prepared_tx(call); break; default: diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index dd2ac5d55e1c..2988e3d0c1f6 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -27,6 +27,7 @@ static void rxrpc_congestion_management(struct rxrpc_call *call, enum rxrpc_congest_change change = rxrpc_cong_no_change; unsigned int cumulative_acks = call->cong_cumul_acks; unsigned int cwnd = call->cong_cwnd; + ktime_t now; bool resend = false; summary->flight_size = @@ -59,13 +60,15 @@ static void rxrpc_congestion_management(struct rxrpc_call *call, /* If we haven't transmitted anything for >1RTT, we should reset the * congestion management state. */ + now = ktime_get_real(); if ((call->cong_mode == RXRPC_CALL_SLOW_START || call->cong_mode == RXRPC_CALL_CONGEST_AVOIDANCE) && ktime_before(ktime_add_us(call->tx_last_sent, - call->peer->srtt_us >> 3), - ktime_get_real()) + call->peer->srtt_us >> 3), now) ) { + trace_rxrpc_reset_cwnd(call, now); change = rxrpc_cong_idle_reset; + rxrpc_inc_stat(call->rxnet, stat_tx_data_cwnd_reset); summary->mode = RXRPC_CALL_SLOW_START; if (RXRPC_TX_SMSS > 2190) summary->cwnd = 2; diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index e5d715b855fc..8147a47d1702 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -485,6 +485,7 @@ dont_set_request_ack: up_read(&conn->local->defrag_sem); if (ret < 0) { + rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail); rxrpc_cancel_rtt_probe(call, serial, rtt_slot); trace_rxrpc_tx_fail(call->debug_id, serial, ret, rxrpc_tx_point_call_data_nofrag); @@ -567,6 +568,7 @@ send_fragmentable: } if (ret < 0) { + rxrpc_inc_stat(call->rxnet, stat_tx_data_send_fail); rxrpc_cancel_rtt_probe(call, serial, rtt_slot); trace_rxrpc_tx_fail(call->debug_id, serial, ret, rxrpc_tx_point_call_data_frag); diff --git a/net/rxrpc/proc.c b/net/rxrpc/proc.c index 5af7c8ee4b1a..6816934cb4cf 100644 --- a/net/rxrpc/proc.c +++ b/net/rxrpc/proc.c @@ -398,13 +398,16 @@ int rxrpc_stats_show(struct seq_file *seq, void *v) struct rxrpc_net *rxnet = rxrpc_net(seq_file_single_net(seq)); seq_printf(seq, - "Data : send=%u sendf=%u\n", + "Data : send=%u sendf=%u fail=%u\n", atomic_read(&rxnet->stat_tx_data_send), - atomic_read(&rxnet->stat_tx_data_send_frag)); + atomic_read(&rxnet->stat_tx_data_send_frag), + atomic_read(&rxnet->stat_tx_data_send_fail)); seq_printf(seq, - "Data-Tx : nr=%u retrans=%u\n", + "Data-Tx : nr=%u retrans=%u uf=%u cwr=%u\n", atomic_read(&rxnet->stat_tx_data), - atomic_read(&rxnet->stat_tx_data_retrans)); + atomic_read(&rxnet->stat_tx_data_retrans), + atomic_read(&rxnet->stat_tx_data_underflow), + atomic_read(&rxnet->stat_tx_data_cwnd_reset)); seq_printf(seq, "Data-Rx : nr=%u reqack=%u jumbo=%u\n", atomic_read(&rxnet->stat_rx_data), @@ -472,8 +475,11 @@ int rxrpc_stats_clear(struct file *file, char *buf, size_t size) atomic_set(&rxnet->stat_tx_data, 0); atomic_set(&rxnet->stat_tx_data_retrans, 0); + atomic_set(&rxnet->stat_tx_data_underflow, 0); + atomic_set(&rxnet->stat_tx_data_cwnd_reset, 0); atomic_set(&rxnet->stat_tx_data_send, 0); atomic_set(&rxnet->stat_tx_data_send_frag, 0); + atomic_set(&rxnet->stat_tx_data_send_fail, 0); atomic_set(&rxnet->stat_rx_data, 0); atomic_set(&rxnet->stat_rx_data_reqack, 0); atomic_set(&rxnet->stat_rx_data_jumbo, 0); -- cgit v1.2.3