From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <ak@muc.de>
Subject: Re: [RFC] TCP congestion schedulers
Date: Sat, 19 Mar 2005 21:19:11 +0100
Message-ID: <m13bur5qyo.fsf@muc.de>
References: <421CF5E5.1060606@ev-en.org>
	<20050223135732.39e62c6c.davem@davemloft.net>
	<421D1E66.5090301@osdl.org> <421D30FA.1060900@ev-en.org>
	<20050225120814.5fa77b13@dxpl.pdx.osdl.net>
	<20050309210442.3e9786a6.davem@davemloft.net>
	<4230288F.1030202@ev-en.org>
	<20050310182629.1eab09ec.davem@davemloft.net>
	<20050311120054.4bbf675a@dxpl.pdx.osdl.net>
	<20050311201011.360c00da.davem@davemloft.net>
	<20050314151726.532af90d@dxpl.pdx.osdl.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: baruch@ev-en.org, netdev@oss.sgi.com
To: Stephen Hemminger <shemminger@osdl.org>
In-Reply-To: <20050314151726.532af90d@dxpl.pdx.osdl.net> (Stephen
 Hemminger's message of "Mon, 14 Mar 2005 15:17:26 -0800")
Sender: netdev-bounce@oss.sgi.com
Errors-to: netdev-bounce@oss.sgi.com
List-Id: netdev.vger.kernel.org

Stephen Hemminger <shemminger@osdl.org> writes:

> Since developers want to experiment with different congestion
> control mechanisms, and the kernel is getting bloated with overlapping
> data structure and code for multiple algorithms; here is a patch to
> split out the Reno, Vegas, Westwood, BIC congestion control stuff
> into an infrastructure similar to the I/O schedulers.

[...]

Did you do any benchmarks to check that wont slow it down? 

I would recommend to try it on a IA64 machine if possible. In the
past we found that adding indirect function calls on IA64 to networking
caused measurable slowdowns in macrobenchmarks.
In that case it was LSM callbacks, but your code looks like it will
add even more.

One way to avoid this concern would be to set up the "standard"
congestion avoidance in a way that it could be inlined.  

-Andi