RELENG_4 -> 5 -> 6: significant performance regression

[Robert Watson]

On Thu, 27 Apr 2006, Dmitry Pryanishnikov 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.

Robert N M Watson