Differential D33035 Diff 102444 share/man/man4/mod_cc.4

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share/man/man4/mod_cc.4

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	memory shortage as the new CC module malloc's memory, that prevented the			memory shortage as the new CC module malloc's memory, that prevented the
	switch is often transient.			switch is often transient.
	.Sh MIB Variables			.Sh MIB Variables
	The framework exposes the following variables in the			The framework exposes the following variables in the
	.Va net.inet.tcp.cc			.Va net.inet.tcp.cc
	branch of the			branch of the
	.Xr sysctl 3			.Xr sysctl 3
	MIB:			MIB:
	.Bl -tag -width ".Va abe_frlossreduce"			.Bl -tag -width ".Va hystartplusplus.css_growth_div"
	.It Va available			.It Va available
	Read-only list of currently available congestion control algorithms by name.			Read-only list of currently available congestion control algorithms by name.
				tuexenUnsubmitted Done Inline Actions I guess changing `control` to `coyntrol` was not intended. tuexen: I guess changing `control` to `coyntrol` was not intended.
	.It Va algorithm			.It Va algorithm
	Returns the current default congestion control algorithm when read, and changes			Returns the current default congestion control algorithm when read, and changes
	the default when set.			the default when set.
	When attempting to change the default algorithm, this variable should be set to			When attempting to change the default algorithm, this variable should be set to
	one of the names listed by the			one of the names listed by the
	.Va net.inet.tcp.cc.available			.Va net.inet.tcp.cc.available
	MIB variable.			MIB variable.
	.It Va abe			.It Va abe
	Enable support for RFC 8511,			Enable support for RFC 8511,
	which alters the window decrease factor applied to the congestion window in			which alters the window decrease factor applied to the congestion window in
	response to an ECN congestion signal.			response to an ECN congestion signal.
	Refer to individual congestion control man pages to determine if they implement			Refer to individual congestion control man pages to determine if they implement
	support for ABE and for configuration details.			support for ABE and for configuration details.
	.It Va abe_frlossreduce			.It Va abe_frlossreduce
	If non-zero, apply standard beta instead of ABE-beta during ECN-signalled			If non-zero, apply standard beta instead of ABE-beta during ECN-signalled
	congestion recovery episodes if loss also needs to be repaired.			congestion recovery episodes if loss also needs to be repaired.
				.It Va hystartplusplus.bblogs
				This boolean controls if black box logging will be done for hystart++ events.
				If set to zero (the default) no logging is performed.
				If set to one then black box logs will be generated on all hystart++ events.
				.It Va hystartplusplus.css_rounds
				This value controls the number of rounds that CSS runs for.
				The default value matches the current internet-draft of 5.
				.It Va hystartplusplus.css_growth_div
				This value controls the divisor applied to slowstart during CSS.
				The default value matches the current internet-draft of 4.
				.It Va hystartplusplus.n_rttsamples
				This value controls how many rtt samples must be collected in each round for
				hystart++ to be active.
				The default value matches the current internet-draft of 8.
				.It Va hystartplusplus.maxrtt_thresh
				This value controls the maximum rtt variance clamp when considering if CSS is needed.
				The default value matches the current internet-draft of 16000 (in microseconds).
				For further explanation please see the internet-draft.
				.It Va hystartplusplus.minrtt_thresh
				This value controls the minimum rtt variance clamp when considering if CSS is needed.
				The default value matches the current internet-draft of 4000 (in microseconds).
				For further explanation please see the internet-draft.
	.El			.El
	.Pp			.Pp
	Each congestion control module may also expose other MIB variables			Each congestion control module may also expose other MIB variables
	to control their behaviour.			to control their behaviour.
				Note that both newreno and cubic now support hystart++ based on the version 3 of the internet-draft.
	.Sh Kernel Configuration			.Sh Kernel Configuration
	.Pp			.Pp
	All of the available congestion control modules may also be loaded			All of the available congestion control modules may also be loaded
	via kernel configutation options.			via kernel configutation options.
	A kernel configuration is required to have at least one congestion control			A kernel configuration is required to have at least one congestion control
	algorithm built into it via kernel option and a system default specified.			algorithm built into it via kernel option and a system default specified.
	Compilation of the kernel will fail if these two conditions are not met.			Compilation of the kernel will fail if these two conditions are not met.
	.Sh Kernel Configuration Options			.Sh Kernel Configuration Options
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