Subject: Re: [net-next-2.6 PATCH] net: fast consecutive name allocation

From: Benjamin LaHaise <[email-masked]>
Date: Sun, 15 Nov 2009 11:50:15 -0500

Hi Denys,

On Sun, Nov 15, 2009 at 03:55:14AM +0200, Denys Fedoryschenko wrote:
> And interface creation speed is important for me, when electricity goes down 
> here, many customers disconnects (up to 500 on single NAS), and then join 
> again to NAS. Load average was jumping to sky on such situations, just option 
> to not create sysfs entries helped me a lot (was posted recently).
> Electricity outage is usual here, happens 2-3 times daily.

This is exactly the type of scenario I'm looking at.  The design of the 
Babylon PPP stack is meant to scale somewhat better that pppd.  It uses a 
single process (although I'm starting to add threads to improve scaling on 
SMP systems) for all PPP/L2TP sessions, and has rather lower connection 
setup overhead (no fork()/exec() being the biggest one).  With udev tuned, 
irqbalance disabled and a few other tweaks, it gets >500 connections per 
second in startup on a modern 2.6GHz processor for L2TP traffic.  There 
is PPPoE support, but it needs a bit more work done to scale automatically 
(there are a few hardcoded limits in the PPPoE implementation).

		-ben