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Date: Wed, 8 Feb 2012 17:01:46 +0400
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: Dmitrij Tejblum <tejblum@yandex-team.ru>
Message-ID: <20120208130146.GH13554@FreeBSD.org>
References: <201202081050.q18AoBwY042112@freefall.freebsd.org>
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Cc: freebsd-net@FreeBSD.org
Subject: Re: kern/161899: [route] ntpd(8): Repeating RTM_MISS packets causing
 high CPU load for ntpd
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  Dmitrij,

On Wed, Feb 08, 2012 at 10:50:11AM +0000, Dmitrij Tejblum wrote:
D>  I would suggest to remove RTM_MISS messages at all. I believe that there 
D>  is no sofware that actually use it. OTOH, in some cases RTM_MISS 
D>  messages are really disturbing.
D>  
D>  E.g., a router without default route (e.g. runnung BGP) will always 
D>  generate some amount of RTM_MISS messages. They have no use, but require 
D>  daemons to parse them, and could result in overflow on routing socket 
D>  queue and, in turn, cause some important routing messages to be dropped.
D>  
D>  I have a patch that add a sysctl to turn off RTM_MISS messages, but 
D>  since no one use them, it would be easier to just remove them entirely.

Sounds reasonable. A patch that adds a sysctl is definitely a commit candidate.
But we can't be sure that no one uses these messages, so we can't remove them
entirely.

-- 
Totus tuus, Glebius.