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Date: Fri, 30 Dec 2011 16:57:54 -0800
From: Maxim Sobolev <sobomax@FreeBSD.org>
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Cc: freebsd-net@freebsd.org, "Bjoern A. Zeeb" <bz@FreeBSD.ORG>,
	Jack Vogel <jfvogel@gmail.com>
Subject: Re: Panic in the udp_input() under heavy load
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On 12/30/2011 4:46 PM, Maxim Sobolev wrote:
> I see. Would you guys mind if I put that NULL pointer check into the
> code for the time being and turn it into some kind of big nasty warning
> in 8-stable branch only?

I could also open a ticket, put all debug information collected to date 
in there. And encourage people to report to it once they see this 
warning on their system. Then it would provide more information about 
the exposure. It is definitely looks like locking issue somewhere, not 
just bad luck or flaky hardware, as we see it happening consistently on 
top 4 most UDP-loaded systems here, and it correlates well with the 
load. With my small NULL catch the machines have been running happily 
for a month now, so there is no visible side-effects.

-Maxim