[PATCH net-next v2 26/39] rxrpc: Generate rtt_min
From: David Howells <dhowells@redhat.com>
Date: 2024-12-04 07:49:10
Also in:
lkml
Subsystem:
library code, networking [general], rxrpc sockets (af_rxrpc), the rest · Maintainers:
Andrew Morton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Howells, Marc Dionne, Linus Torvalds
Generate rtt_min as this is required by RACK-TLP. Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org --- lib/win_minmax.c | 1 + net/rxrpc/ar-internal.h | 2 ++ net/rxrpc/rtt.c | 20 ++++++++++++++++---- 3 files changed, 19 insertions(+), 4 deletions(-)
diff --git a/lib/win_minmax.c b/lib/win_minmax.c
index ec10506834b6..1682e614309c 100644
--- a/lib/win_minmax.c
+++ b/lib/win_minmax.c@@ -97,3 +97,4 @@ u32 minmax_running_min(struct minmax *m, u32 win, u32 t, u32 meas) return minmax_subwin_update(m, win, &val); } +EXPORT_SYMBOL(minmax_running_min);
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 297be421639c..d0d0ab453909 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h@@ -371,6 +371,8 @@ struct rxrpc_peer { spinlock_t rtt_input_lock; /* RTT lock for input routine */ ktime_t rtt_last_req; /* Time of last RTT request */ unsigned int rtt_count; /* Number of samples we've got */ + unsigned int rtt_taken; /* Number of samples taken (wrapping) */ + struct minmax min_rtt; /* Estimated minimum RTT */ u32 srtt_us; /* smoothed round trip time << 3 in usecs */ u32 mdev_us; /* medium deviation */
diff --git a/net/rxrpc/rtt.c b/net/rxrpc/rtt.c
index 6dc51486b5a6..8048467f4bee 100644
--- a/net/rxrpc/rtt.c
+++ b/net/rxrpc/rtt.c@@ -127,16 +127,27 @@ static void rxrpc_set_rto(struct rxrpc_peer *peer) peer->rto_us = rxrpc_bound_rto(rto); } -static void rxrpc_ack_update_rtt(struct rxrpc_peer *peer, long rtt_us) +static void rxrpc_update_rtt_min(struct rxrpc_peer *peer, ktime_t resp_time, long rtt_us) +{ + /* Window size 5mins in approx usec (ipv4.sysctl_tcp_min_rtt_wlen) */ + u32 wlen_us = 5ULL * NSEC_PER_SEC / 1024; + + minmax_running_min(&peer->min_rtt, wlen_us, resp_time / 1024, + (u32)rtt_us ? : jiffies_to_usecs(1)); +} + +static void rxrpc_ack_update_rtt(struct rxrpc_peer *peer, ktime_t resp_time, long rtt_us) { if (rtt_us < 0) return; - //rxrpc_update_rtt_min(peer, rtt_us); + /* Update RACK min RTT [RFC8985 6.1 Step 1]. */ + rxrpc_update_rtt_min(peer, resp_time, rtt_us); + rxrpc_rtt_estimator(peer, rtt_us); rxrpc_set_rto(peer); - /* RFC6298: only reset backoff on valid RTT measurement. */ + /* Only reset backoff on valid RTT measurement [RFC6298]. */ peer->backoff = 0; }
@@ -157,9 +168,10 @@ void rxrpc_peer_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why, return; spin_lock(&peer->rtt_input_lock); - rxrpc_ack_update_rtt(peer, rtt_us); + rxrpc_ack_update_rtt(peer, resp_time, rtt_us); if (peer->rtt_count < 3) peer->rtt_count++; + peer->rtt_taken++; spin_unlock(&peer->rtt_input_lock); trace_rxrpc_rtt_rx(call, why, rtt_slot, send_serial, resp_serial,