Differences in malloc between 6 and 7?

[Bakul Shah]

On Mon, 03 Mar 2008 15:23:33 EST gnn at freebsd.org  wrote:
> One of the folks I'm working with found this.  The following code,
> which yes, is just an example, is 1/2 as fast on 7.0-RELEASE as on
> 6.3.  Where should I look to find out why?

Specifying malloc option K (double virtual memory chunk size)
roughly halves the runtime.  Additional Ks reduce it more and
more.  As this test spends most of its time in the kernel,
may be this is just due to the mmap overhead? Or may be the
defaults for 6.3 were different.