Message-ID: <47585D66.3000404@nortel.com>
Date: Thu, 06 Dec 2007 14:36:54 -0600
From: "Chris Friesen" <cfriesen@nortel.com>
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To: Andi Kleen <andi@firstfloor.org>
CC: Renzo Davoli <renzo@cs.unibo.it>, linux-kernel@vger.kernel.org
Subject: Re: New Address Family: Inter Process Networking (IPN)
References: <20071205164055.GA2082@cs.unibo.it> <p73bq94k8yd.fsf@bingen.suse.de> <20071206053016.GA1464@cs.unibo.it> <20071206163538.GC20595@one.firstfloor.org>
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Andi Kleen wrote:
>>"This document describes Linux Netlink, which is used in Linux both as
>>   an intra-kernel messaging system as well as between kernel and user
>>   space."
> 
> 
> It can be used between user space daemons as well. In fact it is.
> e.g. they often listen to each other's messages.

One problem we ran into was that there are only 32 multicast groups per 
netlink protocol family.

We had a situation where we could have used netlink, but we needed the 
equivalent of thousands of multicast groups.  Latency was very 
important, so we ended up doing essentially a multicast unix socket 
rather than taking the extra penalty for UDP multicast.

Chris
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