linux-kernel - Re: What happened to CONFIG_TCP_NAGLE

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Message-ID: <bdd6985b0611300921u1a88f410vdaf9051c220719e1@mail.gmail.com>
Date:	Thu, 30 Nov 2006 11:21:44 -0600
From:	"Matt Garman" <matthew.garman@...il.com>
To:	"Phillip Susi" <psusi@....rr.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: What happened to CONFIG_TCP_NAGLE_OFF?

On 11/29/06, Phillip Susi <psusi@....rr.com> wrote:
> > How might I achieve having TCP_NODELAY effectively set for all sockets
> > (by default)?  Is there a new/different kernel config option, a patch,
> > a sysctl or proc setting?  Or can I "fake" this behavior by, e.g.
> > setting a send buffer sufficiently small?
>
> This is a bad idea and breaks api compatibility.  Nagle is very
> important for sockets being used for things like telnet.  Other
> applications, like ftp, should already disable nagle themselves.

I don't want to change the API at all.  I'm using a closed-source, 3rd
party library.  Using strace, I can see that the library does *not* do
a setsockopt(...TCP_NODELAY...) on opened sockets.  Since I can't
change the library, I would like to patch and/or configure my kernel
so that all TCP/IP sockets default to TCP_NODELAY.

Also, if my understanding of Nagle is correct, I think you have that
backwards: Nagle should be disabled (i.e. TCP_NODELAY) for telnet,
mouse movements, etc: we always want to send our packets, regardless
of size or previous packet ACK.

Thanks,
Matt
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