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From: des@des.no (Dag-Erling =?iso-8859-1?Q?Sm=F8rgrav?=)
To: Dmitry Morozovsky <marck@rinet.ru>
References: <200609141232.k8ECWTXj045191@lurza.secnetix.de>
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Date: Mon, 25 Sep 2006 13:32:31 +0200
In-Reply-To: <20060920123940.W63482@woozle.rinet.ru> (Dmitry Morozovsky's
	message of "Wed, 20 Sep 2006 12:45:37 +0400 (MSD)")
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Cc: freebsd-hackers@freebsd.org, Kris Kennaway <kris@obsecurity.org>
Subject: Re: numbers don't lie ...
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Dmitry Morozovsky <marck@rinet.ru> writes:
> Kris Kennaway <kris@obsecurity.org> wrote:
> > Dmitry Morozovsky <marck@rinet.ru> writes:
> > > My experiments show that if you have enough memory to host radmdrive =
for
> > > /usr/src you'd better leave it for caching - there were no statistica=
lly
> > > meaningful performance difference, at least on machines with 1G+ RAM.
> > Really?  My measurements show the opposite (on a system with 16GB of
> > RAM).
> My last test on amd64/dualcore with 4G of RAM and -j4 shows
> (buildworld+buildkernel):
>
> =3D=3D> /tmp/buildlog <=3D=3D
>      1996.45 real      3032.94 user       624.83 sys
> Script done on Tue Sep 19 14:44:54 2006
>
> =3D=3D> /tmp/buildlog.md <=3D=3D
>      1957.45 real      3033.93 user       585.78 sys
> Script done on Tue Sep 19 15:20:42 2006
>
> Second one was with 512M/4k/512 swap-backed md, the former with /usr/src =
on the
> gmirror'ed pair of SATAs.

Seems to me that your own numbers contradict you.  You saved about 40
seconds (2%) by keeping /usr/src in a ram disk.

DES
--=20
Dag-Erling Sm=F8rgrav - des@des.no