From owner-freebsd-questions@FreeBSD.ORG Thu Nov 11 08:19:24 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 58F1416A4CE for ; Thu, 11 Nov 2004 08:19:24 +0000 (GMT) Received: from kane.otenet.gr (kane.otenet.gr [195.170.0.27]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4995843D1D for ; Thu, 11 Nov 2004 08:19:20 +0000 (GMT) (envelope-from keramida@ceid.upatras.gr) Received: from orion.daedalusnetworks.priv (aris.bedc.ondsl.gr [62.103.39.226])iAB8JFPd009526; Thu, 11 Nov 2004 10:19:17 +0200 Received: from orion.daedalusnetworks.priv (orion [127.0.0.1]) iAB8JDce000906; Thu, 11 Nov 2004 10:19:13 +0200 (EET) (envelope-from keramida@ceid.upatras.gr) Received: (from keramida@localhost)iAB8JDgw000905; Thu, 11 Nov 2004 10:19:13 +0200 (EET) (envelope-from keramida@ceid.upatras.gr) Date: Thu, 11 Nov 2004 10:19:13 +0200 From: Giorgos Keramidas To: LEI CHEN Message-ID: <20041111081913.GA710@orion.daedalusnetworks.priv> References: <1100098727.8070.5.camel@Tany.tabcuz.net> <20041110150727.GA33927@orion.daedalusnetworks.priv> <1100101672.8070.12.camel@Tany.tabcuz.net> <20041110155146.GA60145@orion.daedalusnetworks.priv> <1100103100.8070.15.camel@Tany.tabcuz.net> <20041110171405.GA1413@orion.daedalusnetworks.priv> <1100109989.8070.22.camel@Tany.tabcuz.net> <20041111054137.GA656@gothmog.gr> <1100153205.8070.28.camel@Tany.tabcuz.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1100153205.8070.28.camel@Tany.tabcuz.net> cc: freebsd-questions@freebsd.org Subject: Re: about the tmpmfs="YES" in rc.conf X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Nov 2004 08:19:24 -0000 On 2004-11-11 16:36, LEI CHEN wrote: >On Thu, 2004-11-11 at 16:11, Giorgos Keramidas wrote: >>On 2004-11-11 04:36, LEI CHEN wrote: >>>On Thu, 2004-11-11 at 03:44, Giorgos Keramidas wrote: >>>> If you're using the -pipe option of gcc, it shouldn't make such a >>>> great difference where /tmp is. I suspect it will make a HUGE >>>> difference where your /usr/obj tree is stored though. >>> >>> yes, I've read this in the handbook, /usr/obj shadows /usr/src >>> directories. But how can I put it into memory? >> >> Using mdmfs(8). The mdmfs(8) utility is what does all the work >> behind the tmpmfs="YES" option in rc.conf. > > I've found this url > http://bsdvault.net/sections.php?op=viewarticle&artid=53 > very helpful. > > But I got only 256Mb of memory, so I can't mount 300Mb mfs into RAM. Hmm, then it's probably not a very good idea to mount /usr/obj as a memory disk. Using swap backed (instead of malloc backed) md file systems is something I haven't tested, but my intuition says it's not going to be much faster than using a real disk partition. It's more likely to be slower, IMHO. > And therefore I can only mount 128Mb or so. Well in this case, would > there be a memory overflow during make world? And what to do if this > is the case? A filesystem overflow (and a broken buildworld because of the inability to write some object files), yes. A memory overflow, no, not really.