There was some possible confusion between fields related to congestion
window size min and max limit which cannot be exceeded, and the maximum
value previously reached by the window.
Fix this by adopting a new naming scheme. Enforced limit are now renamed
<limit_max>/<limit_min>, while the previously reached max value is
renamed <cwnd_last_max>.
This should be backported up to 3.1.
Pacing support was previously activated on each bind line individually,
via an optional argument of quic-cc-algo keyword. Remove this optional
argument and introduce a global setting to enable/disable pacing. Pacing
activation is still flagged as experimental.
One important change is that previously BBR usage automatically
activated pacing support. This is not the case anymore, so users should
now always explicitely activate pacing if BBR is selected. A new warning
message will be displayed if this is not the case.
Another consequence of this change is that now pacing_inter callback is
always defined for every quic_cc_algo types. As such, QUIC MUX uses
global.tune.options to determine if pacing is required.
This should be backported up to 3.1, after a period of observation.
Extend extra pacing support for newreno and nocc congestion algorithms,
as with cubic.
For better extensibility of cc algo definition, define a new flags field
in quic_cc_algo structure. For now, the only value is
QUIC_CC_ALGO_FL_OPT_PACING which is set if pacing support can be
optionally activated. Both cubic, newreno and nocc now supports this.
This new flag is then reused by QUIC config parser. If set, extra
quic-cc-algo burst parameter is taken into account. If positive, this
will activate pacing support on top of the congestion algorithm. As with
cubic previously, pacing is only supported if running under experimental
mode.
Only BBR is not flagged with this new value as pacing is directly
builtin in the algorithm and cannot be turn off. Furthermore, BBR
calculates automatically its value for maximum burst. As such, any
quic-cc-algo burst argument used with BBR is still ignored with a
warning.
Move quic_path struct from quic_conn-t.h to quic_cc-t.h and rename it to quic_cc_path.
Update the code consequently.
Also some inlined functions in relation with QUIC path to quic_cc.h
Make all the congestion support the maximum congestion control window
set by configuration. There is nothing special to explain. For each
each algo, each time the window is incremented it is also bounded.
Move all QUIC trace definitions from quic_conn.h to quic_trace-t.h. Also
remove multiple definition trace_quic macro definition into
quic_trace.h. This forces all QUIC source files who relies on trace to
include it while reducing the size of quic_conn.h.
This very old bug is there since the first implementation of newreno congestion
algorithm implementation. This was a very bad idea to put a state variable
into quic_cc_algo struct which only defines the congestion control algorithm used
by a QUIC listener, typically its type and its callbacks.
This bug could lead to crashes since BUG_ON() calls have been added to each algorithm
implementation. This was revealed by interop test, but not very often as there was
not very often several connections run at the time during these tests.
Hopefully this was also reported by Tristan in GH #2095.
Move the congestion algorithm state to the correct structures which are private
to a connection (see cubic and nr structs).
Must be backported to 2.7 and 2.6.
This algorithm does nothing except initializing the congestion control window
to a fixed value. Very smart!
Modify the QUIC congestion control configuration parser to support this new
algorithm. The congestion control algorithm must be set as follows:
quic-cc-algo nocc-<cc window size(KB))
For instance if "nocc-15" is provided as quic-cc-algo keyword value, this
will set a fixed window of 15KB.
