diff options
| author | David Howells <dhowells@redhat.com> | 2024-12-04 07:46:57 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-12-09 13:48:30 -0800 |
| commit | 5c0ceba23bb47085d6c9c53bff08a29634ee4e7e (patch) | |
| tree | e0c6028976e4ba3a1140fe9648e6967dac74c8cc /net/rxrpc | |
| parent | a3d7f46d983fb2ed528b9cceb457c067fe4277a2 (diff) | |
rxrpc: Fix the calculation and use of RTO
Make the following changes to the calculation and use of RTO:
(1) Fix rxrpc_resend() to use the backed-off RTO value obtained by calling
rxrpc_get_rto_backoff() rather than extracting the value itself.
Without this, it may retransmit packets too early.
(2) The RTO value being similar to the RTT causes a lot of extraneous
resends because the RTT doesn't end up taking account of clearing out
of the receive queue on the server. Worse, responses to PING-ACKs are
made as fast as possible and so are less than the DATA-requested-ACK
RTT and so skew the RTT down.
Fix this by putting a lower bound on the RTO by adding 100ms to it and
limiting the lower end to 200ms.
Fixes: c410bf01933e ("rxrpc: Fix the excessive initial retransmission timeout")
Fixes: 37473e416234 ("rxrpc: Clean up the resend algorithm")
Signed-off-by: David Howells <dhowells@redhat.com>
Suggested-by: Simon Wilkinson <sxw@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/rxrpc')
| -rw-r--r-- | net/rxrpc/call_event.c | 3 | ||||
| -rw-r--r-- | net/rxrpc/rtt.c | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index f71773b18e22..4390c97e3ba6 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -103,7 +103,8 @@ void rxrpc_resend(struct rxrpc_call *call, rxrpc_serial_t ack_serial, bool ping_ .now = ktime_get_real(), }; struct rxrpc_txqueue *tq = call->tx_queue; - ktime_t lowest_xmit_ts = KTIME_MAX, rto = ns_to_ktime(call->peer->rto_us * NSEC_PER_USEC); + ktime_t lowest_xmit_ts = KTIME_MAX; + ktime_t rto = rxrpc_get_rto_backoff(call->peer, false); bool unacked = false; _enter("{%d,%d}", call->tx_bottom, call->tx_top); diff --git a/net/rxrpc/rtt.c b/net/rxrpc/rtt.c index e0b7d99854b4..3f1ec8e420a6 100644 --- a/net/rxrpc/rtt.c +++ b/net/rxrpc/rtt.c @@ -27,7 +27,7 @@ static u32 __rxrpc_set_rto(const struct rxrpc_peer *peer) static u32 rxrpc_bound_rto(u32 rto) { - return umin(rto, RXRPC_RTO_MAX); + return clamp(200000, rto + 100000, RXRPC_RTO_MAX); } /* |