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From: Robert Watson <rwatson@FreeBSD.org>
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To: Julian Elischer <julian@elischer.org>
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Cc: FreeBSD Net <freebsd-net@freebsd.org>, freebsd-virtualization@freebsd.org
Subject: Re: Developers adding global variables.
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On Sun, 3 Aug 2008, Julian Elischer wrote:

> If you are adding globals to the networking code, (or if you have added soem 
> globals in the last few months, could you make sure that I am aware of them?
>
> marko Zec and I are trying to keep teh Vimage tree in perforce in sync with 
> -current but there is noo automatic way that we would be noticfied of the 
> sudden appearance of a new global variable in the networking code.
>
> Today I noticed tcp_do_ecn and tcp_ecn_maxretries but only because of their 
> proximity to another change.

While not a universal solution, one technique you could use to catch things 
like this is to compare the set of symbols in a !virtualization kernel with 
those in a virtualization kernels, perhaps using nm(1), and compare that 
difference set over time.  Not perfect, but it would allow you to look for 
things that have been missed.

FWIW, I have no immediate plans to add any global variables to the network 
stack.

Robert N M Watson
Computer Laboratory
University of Cambridge