From owner-freebsd-java@FreeBSD.ORG Fri Nov 10 22:34:38 2006 Return-Path: X-Original-To: freebsd-java@freebsd.org Delivered-To: freebsd-java@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 57BB616A542 for ; Fri, 10 Nov 2006 22:34:38 +0000 (UTC) (envelope-from freebsd@spatula.net) Received: from turing.morons.org (morons.org [64.147.161.226]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5A03D43D8F for ; Fri, 10 Nov 2006 22:33:33 +0000 (GMT) (envelope-from freebsd@spatula.net) Received: by turing.morons.org (Postfix, from userid 1001) id 2D8C317035; Fri, 10 Nov 2006 14:33:33 -0800 (PST) Received: from localhost (localhost [127.0.0.1]) by turing.morons.org (Postfix) with ESMTP id 29BDC1702F; Fri, 10 Nov 2006 14:33:33 -0800 (PST) Date: Fri, 10 Nov 2006 14:33:33 -0800 (PST) From: Nick Johnson X-X-Sender: spatula@turing To: Nikos Ntarmos In-Reply-To: <20061110213313.GA72658@ace.b020.ceid.upatras.gr> Message-ID: <20061110142436.G88944@turing> References: <20061110203714.GA89006@ace.b020.ceid.upatras.gr> <20061110124459.M88944@turing> <20061110213313.GA72658@ace.b020.ceid.upatras.gr> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-java@freebsd.org Subject: Re: Performance of Java on FBSD vs. others... X-BeenThere: freebsd-java@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting Java to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Nov 2006 22:34:38 -0000 On Fri, 10 Nov 2006, Nikos Ntarmos wrote: >> What about default GC tuning options? These can be platform-dependent. >> You may want to explicitly set these to compare apples to apples. > > My main consideration is not the fairness of the comparison but the > difference in speed. I've tried all possible -X combinations but > (guessed it?) without any noticeable difference; FreeBSD remains the > lagger... How can you compare differences in speed without comparing in the same set of circumstances? Otherwise, you're comparing apples to oranges and the comparison is not valid. > I was thinking something along the lines of "there are bits and pieces > of jre/jdk implemented in native code and fbsd doesn't have'em yet", or > (hopefully) "you have to sysctl-turn a.b.c on"... I can't imagine there is anything like that, since what gets compiled with the port (and what's included in the package) is a stock Sun JVM with patches applied to get it to compile and run correctly on FreeBSD. Did you compile the port or did you use the precompiled binary? It's also conceivable that the other platform JVMs are compiled with a more aggressive set of compiler optimizations, etc. You may notice a difference if the port is compiled with "CPUTYPE?=i686" in /etc/make.conf, for example. I can't really say for sure. Have you tried attaching to the JVM with VisualGC to watch what's going on in memory? Perhaps things are allocated differently by default on the different platforms. How was your kernel compiled? There are certainly tweaks to kernels that can make a major difference in performance. The default Generic kernel is pretty conservative. Options for AUTO_EOI_1, AUTO_EOI_2, HZ, maxusers and so-on can all make a significant difference. Other platforms may ship with a much more aggressive set of defaults. You have to control for these things or you're not doing a legitimate comparison. It's really difficult to guess without a great deal more contextual informaiton. Nick -- When you're a kid, they tell you it's all grow up, get a job, get married, get a house, have a kid, and that's it. No, the truth is the world is so much stranger than that. It's so much darker, and so much madder. And so much better. -- Elton, Doctor Who, "Love and Monsters" This message has been brought to you by Nick Johnson 2.1 and the number 6. http://healerNick.com/ http://morons.org/ http://spatula.net/