From owner-freebsd-net@FreeBSD.ORG  Wed Aug 14 15:44:19 2013
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Date: Wed, 14 Aug 2013 17:48:53 +0200
From: Luigi Rizzo <rizzo@iet.unipi.it>
To: Marko Zec <zec@fer.hr>
Subject: Re: route/arp lifetime (Re: it's the output, not ack coalescing
 (Re: TSO and FreeBSD vs Linux))
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References: <520A6D07.5080106@freebsd.org> <520B74DD.1060102@ipfw.ru>
 <20130814124024.GA64548@onelab2.iet.unipi.it>
 <201308141740.28779.zec@fer.hr>
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Cc: freebsd-net@freebsd.org, Lev Serebryakov <lev@freebsd.org>,
 FreeBSD Net <net@freebsd.org>, "Alexander V. Chernikov" <melifaro@ipfw.ru>,
 Lawrence Stewart <lstewart@freebsd.org>
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On Wed, Aug 14, 2013 at 05:40:28PM +0200, Marko Zec wrote:
> On Wednesday 14 August 2013 14:40:24 Luigi Rizzo wrote:
> > On Wed, Aug 14, 2013 at 04:15:25PM +0400, Alexander V. Chernikov wrote:
...
> FWIW, apparently we already have that infrastrucure in place - if_rele() 
> calls if_free_internal() only when the last reference to the ifnet is 
> dropped, so with little care this should be usable for caching ifp pointers 
> w/o fears for kernel crashes mentioned above.

maybe Alexander was referring to holding references to the rte entries
returned as a result of the lookup. The rte holds a reference to the ifp.

cheers
luigi