Re: [patch] add tcp congestion control relevant parts

Michael Kerrisk
2008-01-02T09:55:21Z

Stephen Hemminger wrote:
> On Fri, 14 Dec 2007 09:48:32 +0100
> Michael Kerrisk <mtk.manpages@googlemail.com> wrote:
>
>> Hello Linux networking folk,
>>
>> I received the patch below for the tcp.7 man page. Would anybody here be
>> prepared to review the new material / double check the details?
>>
>> Cheers,
>>
>> Michael
>>
>> -------- Original Message --------
>> Subject: [patch] add tcp congestion control relevant parts
>> Date: Wed, 12 Dec 2007 16:40:23 +0100
>> From: Thomas Egerer <thomas.Egerer@secunet.com>
>> To: mtk.manpages@gmail.com
>> CC: linux-man@vger.kernel.org
>>
>> Hello *,
>>
>> man-pages version : 2.70 from http://www.kernel.org/pub/linux/docs/man-pages/
>> All required information were obtained by reading the kernel
>> code/documentation.
>> I'm not sure, whether it is completely bullet proof on when the sysctl
>> variables/socket option first appeared in the kernel, so you might as well
>> drop this information, but I'm pretty sure about how it works.
>> Here we go with my patch:
>>
>> diff -ru man-pages-2.70/man7/tcp.7 man-pages-2.70.new/man7/tcp.7
>> --- man-pages-2.70/man7/tcp.7 2007-11-24 14:33:34.000000000 +0100
>> +++ man-pages-2.70.new/man7/tcp.7 2007-12-12 16:34:52.000000000 +0100
>> @@ -177,8 +177,6 @@
>> .\" FIXME As at Sept 2006, kernel 2.6.18-rc5, the following are
>> .\" not yet documented (shown with default values):
>> .\"
>> -.\" /proc/sys/net/ipv4/tcp_congestion_control (since 2.6.13)
>> -.\" bic
>> .\" /proc/sys/net/ipv4/tcp_moderate_rcvbuf
>> .\" 1
>> .\" /proc/sys/net/ipv4/tcp_no_metrics_save
>> @@ -224,6 +222,20 @@
>> are reserved for the application buffer.
>> A value of 0
>> implies that no amount is reserved.
>> +.TP
>> +.BR tcp_allowed_congestion_control \
>> +" (String; default: cubic reno) (since 2.6.13) "
>> +Show/set the congestion control choices available to non-privileged
>> +processes. The list is a subset of those listed in
>> +.IR tcp_available_congestion_control "."
>> +Default is "cubic reno" and the default setting
>> +.RI ( tcp_congestion_control ).
>> +.TP
>> +.BR tcp_available_congestion_control \
>> +" (String; default: cubic reno) (since 2.6.13) "
>> +Lists the TCP congestion control algorithms available on the system. This
>> value
>> +can only be changed by loading/unloading modules responsible for congestion
>> +control.
>> .\"
>> .\" The following is from 2.6.12: Documentation/networking/ip-sysctl.txt
>> .TP
>> @@ -257,6 +269,17 @@
>> Allows two flows sharing the same connection to converge
>> more rapidly.
>> .TP
>> +.BR tcp_congestion_control " (String; default: cubic reno) (since 2.6.13) "
>> +Determines the congestion control algorithm used for newly created TCP
>> +sockets. By default Linux uses cubic with reno as fallback. If you want
>> +to have more control over the algorithm used, you must enable the symbol
>> +CONFIG_TCP_CONG_ADVANCED in your kernel config.
>
> You can choose the default congestion control as well as part of the kernel
> configuration.

Hi Stephen,

Other than this, did the doc patch look okay? (I'm not sure whether there
was an implied ACK in your message for the rest of the patch.)

Cheers,

Michael

--
Michael Kerrisk
Maintainer of the Linux man-pages project
http://www.kernel.org/doc/man-pages/
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