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Date: Fri, 12 May 2006 23:32:44 +0300 (EEST)
From: Dmitry Pryanishnikov <dmitry@atlantis.dp.ua>
To: Robert Watson <rwatson@FreeBSD.org>
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Cc: freebsd-stable@FreeBSD.org
Subject: Re: RELENG_4 -> 5 -> 6: significant performance regression
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Hello!

On Tue, 2 May 2006, Robert Watson wrote:
>> options 	INVARIANTS
>> options 	INVARIANT_SUPPORT
>
> In FreeBSD 5.x and FreeBSD 6.x, the INVARIANTS option has been significantly 
> expanded to test a much larger set of invariants, and also incorporate kernel 
> use-after-free checking, which involves memory scrubbing.  This is great for 
> catching bugs, but it will have a significant performance impact, especially 
> for kernel-intensive loads.

  So maybe it's time to add, say,

options      INVARIANTS_EXTENDED

for these new and expensive checks, and leave only basic and cheap (yet
effective for bug hunting) asserts enabled when only

options      INVARIANTS

is defined?

> Robert N M Watson

Sincerely, Dmitry
-- 
Atlantis ISP, System Administrator
e-mail:  dmitry@atlantis.dp.ua
nic-hdl: LYNX-RIPE