This filter is no more needed after this commit:
BUG/MINOR: quic: fix BBB max bandwidth oscillation issue.
Indeed, one added this filter at delivery rate sampling level to filter
the BBR max bandwidth estimations and was inspired from ngtcp2 code source when
trying to fix the oscillation issue. But this BBR max bandwidth oscillation issue
was fixed by the aforementioned commit.
Furthermore this code tends to always increment the BBR max bandwidth. From my point
of view, this is not a good idea at all.
Must be backported to 3.1.
This patch fixes the loss of information when computing the delivery rate
(quic_cc_drs.c) on links with very low latency due to usage of 32bits
variables with the millisecond as precision.
Initialize the quic_conn task with TASK_F_WANTS_TIME flag ask it to ask
the scheduler to update the call date of this task. This allows this task to get
a nanosecond resolution on the call date calling task_mono_time(). This is enabled
only for congestion control algorithms with delivery rate estimation support
(BBR only at this time).
Store the send date with nanosecond precision of each TX packet into
->time_sent_ns new quic_tx_packet struct member to store the date a packet was
sent in nanoseconds thanks to task_mono_time().
Make use of this new timestamp by the delivery rate estimation algorithm (quic_cc_drs.c).
Rename current ->time_sent member from quic_tx_packet struct to ->time_sent_ms to
distinguish the unit used by this variable (millisecond) and update the code which
uses this variable. The logic found in quic_loss.c is not modified at all.
Must be backported to 3.1.
