From owner-freebsd-hackers@FreeBSD.ORG Fri Mar 25 13:15:05 2011 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C00BE1065674; Fri, 25 Mar 2011 13:15:05 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from mail.ebusiness-leidinger.de (mail.ebusiness-leidinger.de [217.11.53.44]) by mx1.freebsd.org (Postfix) with ESMTP id 6A0748FC14; Fri, 25 Mar 2011 13:15:05 +0000 (UTC) Received: from outgoing.leidinger.net (p5B1553A9.dip.t-dialin.net [91.21.83.169]) by mail.ebusiness-leidinger.de (Postfix) with ESMTPSA id 33153844018; Fri, 25 Mar 2011 14:14:58 +0100 (CET) Received: from webmail.leidinger.net (webmail.Leidinger.net [IPv6:fd73:10c7:2053:1::2:102]) by outgoing.leidinger.net (Postfix) with ESMTP id 026E01478; Fri, 25 Mar 2011 14:14:54 +0100 (CET) Received: (from www@localhost) by webmail.leidinger.net (8.14.4/8.13.8/Submit) id p2PDEnQL015309; Fri, 25 Mar 2011 14:14:49 +0100 (CET) (envelope-from Alexander@Leidinger.net) Received: from pslux.ec.europa.eu (pslux.ec.europa.eu [158.169.9.14]) by webmail.leidinger.net (Horde Framework) with HTTP; Fri, 25 Mar 2011 14:14:49 +0100 Message-ID: <20110325141449.175625s5pqmtbrk0@webmail.leidinger.net> Date: Fri, 25 Mar 2011 14:14:49 +0100 From: Alexander Leidinger To: Andriy Gapon References: <20110325105213.53217afxpg1kj7s4@webmail.leidinger.net> <4D8C74F8.4010303@freebsd.org> In-Reply-To: <4D8C74F8.4010303@freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 7bit User-Agent: Dynamic Internet Messaging Program (DIMP) H3 (1.1.6) X-EBL-MailScanner-Information: Please contact the ISP for more information X-EBL-MailScanner-ID: 33153844018.AD0D7 X-EBL-MailScanner: Found to be clean X-EBL-MailScanner-SpamCheck: not spam, spamhaus-ZEN, SpamAssassin (not cached, score=1.2, required 6, autolearn=disabled, J_CHICKENPOX_32 0.60, J_CHICKENPOX_52 0.60) X-EBL-MailScanner-SpamScore: s X-EBL-MailScanner-From: alexander@leidinger.net X-EBL-MailScanner-Watermark: 1301663700.12118@3o/7kx0J3iGf1hdraGEkIw X-EBL-Spam-Status: No X-Mailman-Approved-At: Fri, 25 Mar 2011 13:25:18 +0000 Cc: hackers@freebsd.org Subject: Re: dtrace sdt problem: my fault or a generic problem (SYSINIT not working as expected for modules)? 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: Fri, 25 Mar 2011 13:15:05 -0000 Quoting Andriy Gapon (from Fri, 25 Mar 2011 12:56:56 +0200): > on 25/03/2011 11:52 Alexander Leidinger said the following: >> As I read it, it looks a little bit like the SYSINIT of the SDT >> probes didn't >> work as expected for my new probes (does this work in modules? >> fxr.watson.org >> AFAICS only lists SDT probes in kernel-code, not in module-code), a >> hit with the >> clue-bat is welcome. > > My reading of the code is that all modules with SDT proivders/probes > should be > loaded before sdt module itself. > SYSINIT in your module(s) works as expect, but dtrace_register() is > not called > on your SDT provider. See sys/cddl/dev/sdt/sdt.c for details: > sdt_modevent -> > sdt_load -> sdt_provider_listall(sdt_provider_reg_callback) -> > dtrace_register. So if I load linux.ko before sdt.ko, or if I unload sdt.ko and reload it, it should work? I'm going to try this after sending this mail. > I am not saying that this behavior is correct/desired, just that > this is what we > have now. Is someone working on this? If not, what would be a solution for this? Adding a call (which one) to the modevent of the module which is using SDT probes? Can we prevent a kernel panic for this case (maybe detecting a NULL ID and skipping... or maybe even registering it)? Something to add to the ideas list as a GSoC entry, or is this too small/big? Bye, Alexander. -- One way to make your old car run better is to look up the price of a new model. http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137