Re: [PATCH] Add somaxconn to Documentation/sysctl/net.txt

Re: [PATCH] Add somaxconn to Documentation/sysctl/net.txt

[Eric Dumazet]

Le mardi 13 avril 2010 à 13:25 -0500, Rob Landley a écrit :
> From: Rob Landley <rob@landley.net>
> 
> Add somaxconn to Documentation/sysctl/net.txt
> 
> Signed-off-by: Rob Landley <rob@landley.net>
> ---
> 
>  Documentation/sysctl/net.txt |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt
> index df38ef0..2740085 100644
> --- a/Documentation/sysctl/net.txt
> +++ b/Documentation/sysctl/net.txt
> @@ -90,6 +90,12 @@ optmem_max
>  Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence
>  of struct cmsghdr structures with appended data.
>  
> +somaxconn
> +---------
> +
> +Maximum backlog of unanswered connections for a listening socket.  Provides
> +an upper bound on the "backlog" parameter of the listen() syscall.
> +
>  2. /proc/sys/net/unix - Parameters for Unix domain sockets
>  -------------------------------------------------------
>  
> 

Please cc netdev for such patches

Extract of Documentation/networking/ip-sysctl.txt

somaxconn - INTEGER
	Limit of socket listen() backlog, known in userspace as SOMAXCONN.
	Defaults to 128.  See also tcp_max_syn_backlog for additional tuning
	for TCP sockets.

I guess you need to change both files ?

Re: [PATCH] Add somaxconn to Documentation/sysctl/net.txt

[Rob Landley]

On Tuesday 13 April 2010 13:40:12 Eric Dumazet wrote:
> Le mardi 13 avril 2010 à 13:25 -0500, Rob Landley a écrit :
> > From: Rob Landley <rob@landley.net>
> >
> > Add somaxconn to Documentation/sysctl/net.txt
> >
> > Signed-off-by: Rob Landley <rob@landley.net>
> > ---
> >
> >  Documentation/sysctl/net.txt |    6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt
> > index df38ef0..2740085 100644
> > --- a/Documentation/sysctl/net.txt
> > +++ b/Documentation/sysctl/net.txt
> > @@ -90,6 +90,12 @@ optmem_max
> >  Maximum ancillary buffer size allowed per socket. Ancillary data is a
> > sequence of struct cmsghdr structures with appended data.
> >
> > +somaxconn
> > +---------
> > +
> > +Maximum backlog of unanswered connections for a listening socket. 
> > Provides +an upper bound on the "backlog" parameter of the listen()
> > syscall. +
> >  2. /proc/sys/net/unix - Parameters for Unix domain sockets
> >  -------------------------------------------------------
>
> Please cc netdev for such patches
>
> Extract of Documentation/networking/ip-sysctl.txt
>
> somaxconn - INTEGER
> 	Limit of socket listen() backlog, known in userspace as SOMAXCONN.
> 	Defaults to 128.  See also tcp_max_syn_backlog for additional tuning
> 	for TCP sockets.
>
> I guess you need to change both files ?

Dunno.  I just got a question on the busybox mailing list:

  http://lists.busybox.net/pipermail/busybox/2010-April/072090.html

Looked in Documentation to see what /proc/sys/net/core/somaxconn actually 
_did_, found it was undocumented, grepped the kernel source for somaxconn, 
found just one chunk of code actually using it, replied to the guy's question:

  http://lists.busybox.net/pipermail/busybox/2010-April/072096.html

And then tweaked the documentation with what I'd found, and sent in a doc 
patch so I wouldn't have to do that twice.

It's quite possible I got it wrong.  Maybe it's per interface or something?

Rob
-- 
Latency is more important than throughput. It's that simple. - Linus Torvalds