Add a new 'b2hi' connection option which limits the reduction of inflight_hi based on cwnd instead of target inflight. protected by gfe2_reloadable_flag_quic_bbr2_limit_inflight_hi.
PiperOrigin-RevId: 313091939
Change-Id: Ic722bca8e08e42d7b3e3235e8d3c37c9a17ac836
diff --git a/quic/core/congestion_control/bbr2_misc.h b/quic/core/congestion_control/bbr2_misc.h
index e110a4c..ddef772 100644
--- a/quic/core/congestion_control/bbr2_misc.h
+++ b/quic/core/congestion_control/bbr2_misc.h
@@ -184,6 +184,9 @@
// Can be enabled by connection option 'B2LO'.
bool ignore_inflight_lo = false;
+
+ // Can be enabled by connection optoin 'B2HI'.
+ bool limit_inflight_hi_by_cwnd = false;
};
class QUIC_EXPORT_PRIVATE RoundTripCounter {
diff --git a/quic/core/congestion_control/bbr2_probe_bw.cc b/quic/core/congestion_control/bbr2_probe_bw.cc
index 6fb7eee..f6a0938 100644
--- a/quic/core/congestion_control/bbr2_probe_bw.cc
+++ b/quic/core/congestion_control/bbr2_probe_bw.cc
@@ -198,9 +198,9 @@
cycle_.is_sample_from_probing = false;
if (!send_state.is_app_limited) {
- QuicByteCount inflight_at_send = BytesInFlight(send_state);
+ const QuicByteCount inflight_at_send = BytesInFlight(send_state);
- QuicByteCount inflight_target =
+ const QuicByteCount inflight_target =
sender_->GetTargetBytesInflight() * (1.0 - Params().beta);
if (inflight_at_send >= inflight_target) {
// The new code does not change behavior.
@@ -209,7 +209,20 @@
// The new code actually cuts inflight_hi slower than before.
QUIC_CODE_COUNT(quic_bbr2_cut_inflight_hi_gradually_in_effect);
}
- model_->set_inflight_hi(std::max(inflight_at_send, inflight_target));
+ if (Params().limit_inflight_hi_by_cwnd) {
+ const QuicByteCount cwnd_target =
+ sender_->GetCongestionWindow() * (1.0 - Params().beta);
+ if (inflight_at_send >= cwnd_target) {
+ // The new code does not change behavior.
+ QUIC_CODE_COUNT(quic_bbr2_cut_inflight_hi_cwnd_noop);
+ } else {
+ // The new code actually cuts inflight_hi slower than before.
+ QUIC_CODE_COUNT(quic_bbr2_cut_inflight_hi_cwnd_in_effect);
+ }
+ model_->set_inflight_hi(std::max(inflight_at_send, cwnd_target));
+ } else {
+ model_->set_inflight_hi(std::max(inflight_at_send, inflight_target));
+ }
}
QUIC_DVLOG(3) << sender_ << " " << cycle_.phase
diff --git a/quic/core/congestion_control/bbr2_sender.cc b/quic/core/congestion_control/bbr2_sender.cc
index 8c3f7e5..7b891a6 100644
--- a/quic/core/congestion_control/bbr2_sender.cc
+++ b/quic/core/congestion_control/bbr2_sender.cc
@@ -127,6 +127,11 @@
QUIC_RELOADABLE_FLAG_COUNT(quic_bbr2_ignore_inflight_lo);
params_.ignore_inflight_lo = true;
}
+ if (GetQuicReloadableFlag(quic_bbr2_limit_inflight_hi) &&
+ config.HasClientRequestedIndependentOption(kB2HI, perspective)) {
+ QUIC_RELOADABLE_FLAG_COUNT(quic_bbr2_limit_inflight_hi);
+ params_.limit_inflight_hi_by_cwnd = true;
+ }
ApplyConnectionOptions(config.ClientRequestedIndependentOptions(perspective));
}
diff --git a/quic/core/crypto/crypto_protocol.h b/quic/core/crypto/crypto_protocol.h
index 172fd82..36ea6ca 100644
--- a/quic/core/crypto/crypto_protocol.h
+++ b/quic/core/crypto/crypto_protocol.h
@@ -125,6 +125,8 @@
// cwnd to be below BDP + ack
// height.
const QuicTag kB2LO = TAG('B', '2', 'L', 'O'); // Ignore inflight_lo in BBR2
+const QuicTag kB2HI = TAG('B', '2', 'H', 'I'); // Limit inflight_hi reduction
+ // based on CWND.
const QuicTag kBSAO = TAG('B', 'S', 'A', 'O'); // Avoid Overestimation in
// Bandwidth Sampler with ack
// aggregation
