From owner-freebsd-questions@FreeBSD.ORG Tue Jun 21 18:24:39 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org 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 4E3B616A41C for ; Tue, 21 Jun 2005 18:24:39 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 19D1A43D1D for ; Tue, 21 Jun 2005 18:24:36 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from localhost (localhost [127.0.0.1]) by pi.codefab.com (Postfix) with ESMTP id 377245FA7; Tue, 21 Jun 2005 14:24:36 -0400 (EDT) Received: from pi.codefab.com ([127.0.0.1]) by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 14644-05; Tue, 21 Jun 2005 14:24:35 -0400 (EDT) Received: from [192.168.1.3] (pool-68-161-66-3.ny325.east.verizon.net [68.161.66.3]) by pi.codefab.com (Postfix) with ESMTP id 5C2455C46; Tue, 21 Jun 2005 14:24:34 -0400 (EDT) Message-ID: <42B85B62.3030303@mac.com> Date: Tue, 21 Jun 2005 14:24:34 -0400 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.8) Gecko/20050511 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Roland Smith References: <20050621180648.GB40187@slackbox.xs4all.nl> In-Reply-To: <20050621180648.GB40187@slackbox.xs4all.nl> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: amavisd-new at codefab.com Cc: Harrison Peter CSA BIRKENHEAD , freebsd-questions@freebsd.org Subject: Re: -DNOPROFILE with make buildworld... X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Jun 2005 18:24:39 -0000 Roland Smith wrote: > On Tue, Jun 21, 2005 at 01:49:06PM +0100, Harrison Peter CSA BIRKENHEAD wrote: >>I've cvsup'ed my source tree, and stepping through the instructions in >>the handbook I note that it recommends running make buildworld with >>-DNOPROFILE (or specifying it in make.conf). I'm not clear what the >>impact of running profiled libraries is against non-profiled >>libraries. I've done a quick search via google and through the list >>archives without success. Normally, you don't use the profiled versions of libraries unless you are running a binary which links against them. If you are running a binary which has not been compiled with profiling, the toolchain will link it against normal versions of the libraries. [ ... ] > Programs that have been compiled with profiling enabled might run > fractionally slower that without. But I doubt the difference is > significant on a modern machine. The amount of overhead seems to vary by platform, but it's generally only a couple of percent. Not very significant, but maybe noticable. The major downsides to having profiled libraries around is that they use more disk space than normal versions, and it takes longer to do a buildworld, but the runtime performance of the system for normal binaries will not be affected. > I'll be bold and say that modern machines are so fast that there is > seldom need to profile a program. Even people who write code on fast machines may run that code on slower boxes sometime. However, what you've said is still true: there is seldom need to profile a program. Get it working well enough that it doesn't leak memory, and then worry about profiling it. :-) -- -Chuck