From owner-freebsd-hackers@FreeBSD.ORG Mon May 28 15:18:39 2007 Return-Path: X-Original-To: hackers@freebsd.org Delivered-To: freebsd-hackers@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 0699E16A474; Mon, 28 May 2007 15:18:39 +0000 (UTC) (envelope-from stephen@math.missouri.edu) Received: from sccmmhc91.asp.att.net (sccmmhc91.asp.att.net [204.127.203.211]) by mx1.freebsd.org (Postfix) with ESMTP id B341613C4CA; Mon, 28 May 2007 15:18:38 +0000 (UTC) (envelope-from stephen@math.missouri.edu) Received: from laptop2.montlan (12-216-253-187.client.mchsi.com[12.216.253.187]) by sccmmhc91.asp.att.net (sccmmhc91) with ESMTP id <20070528151837m9100d22jne>; Mon, 28 May 2007 15:18:37 +0000 Message-ID: <465AF2CC.9020506@math.missouri.edu> Date: Mon, 28 May 2007 10:18:36 -0500 From: Stephen Montgomery-Smith User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.1.2) Gecko/20070525 SeaMonkey/1.1.1 MIME-Version: 1.0 To: Hartmut Brandt References: <4659EF80.70100@math.missouri.edu> <465AB421.10802@dlr.de> In-Reply-To: <465AB421.10802@dlr.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: ports@freebsd.org, hackers@freebsd.org Subject: Re: Looking for speed increases in "make index" and pkg_version for ports 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: Mon, 28 May 2007 15:18:39 -0000 Hartmut Brandt wrote: > Having done a great deal of rewriting of make some two years ago I can > tell you that even a small change to make is a tough job testing-wise: > run all the combinations of !-j and -j on all architectures and run > the change through the port-building cluster. That's a warning to start > with. > > Second I would start with careful profiling to find out where the > problem actually is. You might be surprised. As an example: several > times the idea came up to use a hash structure instead of linear lists > for make variables. I got a patch for this and - it makes absolutely no > difference performance-wise (well, there was some indication that > performance gets worse, but that was around or below noise level). With > careful I mean to find out who takes the time: Yes, I must admit that I thought that a hash structure for the variables would greatly increase the speed of make. I rewrote it using Berkeley databases, and like you said - absolutely no difference!! I even tried btrees.