From owner-freebsd-hackers@FreeBSD.ORG Tue Sep 26 05:48:48 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 28B2016A417 for ; Tue, 26 Sep 2006 05:48:48 +0000 (UTC) (envelope-from marck@rinet.ru) Received: from woozle.rinet.ru (woozle.rinet.ru [195.54.192.68]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7021843D5F for ; Tue, 26 Sep 2006 05:48:41 +0000 (GMT) (envelope-from marck@rinet.ru) Received: from localhost (localhost [127.0.0.1]) by woozle.rinet.ru (8.13.8/8.13.6) with ESMTP id k8Q5md7O026613; Tue, 26 Sep 2006 09:48:39 +0400 (MSD) (envelope-from marck@rinet.ru) Date: Tue, 26 Sep 2006 09:48:39 +0400 (MSD) From: Dmitry Morozovsky To: Dag-Erling =?iso-8859-1?Q?Sm=F8rgrav?= In-Reply-To: <86hcywrxkg.fsf@dwp.des.no> Message-ID: <20060926094720.Q25959@woozle.rinet.ru> References: <200609141232.k8ECWTXj045191@lurza.secnetix.de> <20060919160511.T33371@woozle.rinet.ru> <20060919173421.GA45928@xor.obsecurity.org> <20060920123940.W63482@woozle.rinet.ru> <86hcywrxkg.fsf@dwp.des.no> X-NCC-RegID: ru.rinet X-OpenPGP-Key-ID: 6B691B03 MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0.2 (woozle.rinet.ru [0.0.0.0]); Tue, 26 Sep 2006 09:48:39 +0400 (MSD) Cc: freebsd-hackers@freebsd.org, Kris Kennaway Subject: Re: numbers don't lie ... X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Sep 2006 05:48:48 -0000 On Mon, 25 Sep 2006, Dag-Erling Sm?rgrav wrote: DS> > > > My experiments show that if you have enough memory to host radmdrive for DS> > > > /usr/src you'd better leave it for caching - there were no statistically DS> > > > meaningful performance difference, at least on machines with 1G+ RAM. DS> > > Really? My measurements show the opposite (on a system with 16GB of DS> > > RAM). DS> > My last test on amd64/dualcore with 4G of RAM and -j4 shows DS> > (buildworld+buildkernel): DS> > DS> > ==> /tmp/buildlog <== DS> > 1996.45 real 3032.94 user 624.83 sys DS> > Script done on Tue Sep 19 14:44:54 2006 DS> > DS> > ==> /tmp/buildlog.md <== DS> > 1957.45 real 3033.93 user 585.78 sys DS> > Script done on Tue Sep 19 15:20:42 2006 DS> > DS> > Second one was with 512M/4k/512 swap-backed md, the former with /usr/src on the DS> > gmirror'ed pair of SATAs. DS> DS> Seems to me that your own numbers contradict you. You saved about 40 DS> seconds (2%) by keeping /usr/src in a ram disk. Well, maybe I did used wrong wording (2% is statistically meaningful), but for me 2% is not worth all the efforts needed to organize ram disk infrastructure... Sincerely, D.Marck [DM5020, MCK-RIPE, DM3-RIPN] ------------------------------------------------------------------------ *** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck@rinet.ru *** ------------------------------------------------------------------------