From owner-freebsd-hackers@FreeBSD.ORG Wed Jul 7 06:31:29 2004 Return-Path: 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 4F12416A4CE for ; Wed, 7 Jul 2004 06:31:29 +0000 (GMT) Received: from mps5.plala.or.jp (c148240.vh.plala.or.jp [210.150.148.240]) by mx1.FreeBSD.org (Postfix) with ESMTP id F2E0A43D1F for ; Wed, 7 Jul 2004 06:31:27 +0000 (GMT) (envelope-from e-kamo@trio.plala.or.jp) Received: from msvc2.plala.or.jp ([172.23.8.210]) by mps5.plala.or.jp with SMTP id <20040707063126.QVZQ2494.mps5.plala.or.jp@msvc2.plala.or.jp> for ; Wed, 7 Jul 2004 15:31:26 +0900 Received: ( 18931 invoked from network); 7 Jul 2004 15:31:26 +0900 X-SVCK: Received: from unknown (HELO mpb1.plala.or.jp) (172.23.8.16) by msvc2 with SMTP; 7 Jul 2004 15:31:25 +0900 Received: from trio.plala.or.jp ([219.25.148.126]) by mpb1.plala.or.jp with ESMTP id <20040707063124.XXVB19716.mpb1.plala.or.jp@trio.plala.or.jp>; Wed, 7 Jul 2004 15:31:24 +0900 Message-ID: <40EB9A46.2050409@trio.plala.or.jp> Date: Wed, 07 Jul 2004 15:37:58 +0900 From: Eitarou Kamo User-Agent: Mozilla/5.0 (Windows; U; Win98; ja-JP; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: ja MIME-Version: 1.0 To: Daniel Ellard , freebsd-hackers@freebsd.org References: <20040706120130.3DF9816A57D@hub.freebsd.org> <20040706101140.T92636@bowser.eecs.harvard.edu> In-Reply-To: <20040706101140.T92636@bowser.eecs.harvard.edu> X-Enigmail-Version: 0.76.8.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: Article on Sun's DTrace X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 07 Jul 2004 06:31:29 -0000 Hi Dan, Daniel Ellard wrote: >In a nutshell, here is what DTrace is about: > >- It has no impact on the system when it is not used. So you can > leave it in all the time, instead of having a debug kernel and > a production kernel. > > [I don't know how they achieve the "no impact" but they claim > that they really mean "no", not just "negligible".] > > Thanks good comment. This is the one everyone, of course me too, wants to know. I wanted to get brief instruction. >So, you could think of it as "a million debugging printf's magically >inserted into the kernel for you" along with a tool to analyze the >output, but it's really much more sophisticated than that. > >It looks very nice. I wish I'd had it during my forays into the >FreeBSD kernel. Is it hopelessly solaris-specific? Well, I was at >the presentation that Bryan Cantrill gave at USENIX, where he was >asked about the possibility of porting DTrace to linux. His response >was something like "well, we're really trying to encourage people to >use the *best* possible operating system, so no." (Of course, one >might argue that this means that a FreeBSD port is imminent, but I >don't think that's what he meant.) > >-Dan > > > FreeBSD has good features such as jail, chroot e.t.c. which can controll process or resources in parallel. So you need not port DTrace entirely. You can implement DTrace like one from scratch. Using legacy system sometimes makes new system feature. I would rather expect new one than porting. DTrace is one of example, I think. You may be able to fork new debug process in parallel in the future. If I dare name it, It's "B(SD)Trace"? But it's up to your effort. DTrace is a pioneer work. And for the people like me who bothers to put the debug lines in kernel this must be powerful tool. Eitarou -- *********************** Eitarou Kamo Tel. +81 75 7035997 Fax +81 75 7035997 VoIP 050 10585997(domestic only) e-mail e-kamo@trio.plala.or.jp For business: Feel free to mail me(above), please. Donation http://www.PayPal.Com GPG FingerPrint: 032D FDF9 D27B 23F7 9A81 BF4C 626C FBAA BC3A 9895 ************************************************************************