[TCP]: Document several sysctls.

This adds documentation for tcp_moderate_rcvbuf, tcp_no_metrics_save,
tcp_base_mss, and tcp_mtu_probing.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Heffner 2007-02-27 10:03:56 -08:00 committed by David S. Miller
parent b08d5840d2
commit 71599cd1c3

View File

@ -147,6 +147,11 @@ tcp_available_congestion_control - STRING
More congestion control algorithms may be available as modules,
but not loaded.
tcp_base_mss - INTEGER
The initial value of search_low to be used by Packetization Layer
Path MTU Discovery (MTU probing). If MTU probing is enabled,
this is the inital MSS used by the connection.
tcp_congestion_control - STRING
Set the congestion control algorithm to be used for new
connections. The algorithm "reno" is always available, but
@ -243,6 +248,27 @@ tcp_mem - vector of 3 INTEGERs: min, pressure, max
Defaults are calculated at boot time from amount of available
memory.
tcp_moderate_rcvbuf - BOOLEAN
If set, TCP performs receive buffer autotuning, attempting to
automatically size the buffer (no greater than tcp_rmem[2]) to
match the size required by the path for full throughput. Enabled by
default.
tcp_mtu_probing - INTEGER
Controls TCP Packetization-Layer Path MTU Discovery. Takes three
values:
0 - Disabled
1 - Disabled by default, enabled when an ICMP black hole detected
2 - Always enabled, use initial MSS of tcp_base_mss.
tcp_no_metrics_save - BOOLEAN
By default, TCP saves various connection metrics in the route cache
when the connection closes, so that connections established in the
near future can use these to set initial conditions. Usually, this
increases overall performance, but may sometimes cause performance
degredation. If set, TCP will not cache metrics on closing
connections.
tcp_orphan_retries - INTEGER
How may times to retry before killing TCP connection, closed
by our side. Default value 7 corresponds to ~50sec-16min